Abstracts of the Fourth Annual Meeting of the Associazione Italiana Sistema Nervoso Periferico, April 13–15, 2014, Sorrento (Na), Italy.

Journal of the Peripheral Nervous System 19(Supplement):S1–S36 (2014)

PROCEEDINGS

Abstracts of the Fourth Annual Meeting of the Associazione Italiana Sistema Nervoso Periferico April 13–15, 2014 Sorrento (Na), Italy President: Lucio Santoro Scientific Committee: Guido Cavaletti, Emilia Bellone, Chiara Briani, Marinella Carpo, Dario Cocito, Gianmaria Fabrizi, Fiore Manganelli, Luca Padua, Davide Pareyson, Stefano Previtali, Angelo Schenone Organizing Committee: Lucio Santoro, Maria Nolano, Fiore Manganelli Organizing Secretariat: the office srl www.theoffice.it reduction in the common peroneal nerve. Routine blood testing and onconeural antibodies were normal or negative. Gadolinium-enhanced brain and spinal cord MRI were normal. After IVIG administration the symptoms worsened. A neurological consult was obtained. Inability to stand, walk unattended for a severe sensory ataxia, and bladder dysfunction were observed. A subsequent MRI showed an altered pattern in the dorsal columns from the cervical to the dorsal spinal cord. Somatosensory evoked potentials (SSEP) revealed intraspinal sensory ascending pathways damage. NCS now evidenced a peripheral, mainly motor, involvement with diminished conduction velocities, augmented distal latencies and augmented F waves in lower limb nerves; these findings were stable during subsequent NCS monitoring. A bone marrow biopsy and positron emission tomography (PET) excluded a relapse. The neurological disturbance was then regarded as iatrogenic so no other specific treatment for neurological symptoms than long-term physiotherapy was performed and immunotherapy with donor lymphocytes infusion (DLI) was allowed, to maintain the oncological remission status. One year after the patient was asymptomatic and in complete remission. Only minor alterations were still present on MRI and SSEP. Nelarabine neurotoxicity can cause a severe neuropathy/myelopathy, still potentially reversible, provided prolonged physiotherapy, since no medical treatment is available. Thus, for nelarabine-treated patients, neurological monitoring should be suggested. DLI was performed without any worsening of neurological outcome, different from what was previously reported.

NELARABINE-INDUCED NEUROTOXICITY: REVERSIBLE DAMAGE NOT ONLY ON PERIPHERAL NERVES Alberti P1 , Parma M2 , Cavaletti G1 . 1 Department of Surgery and Translational Medicine, University of Milano-Bicocca, Monza, Italy; 2 Department of Haematology, San Gerardo Hospital, Monza, Italy. Nelarabine has a T-cell-specific action; neurotoxicity is an important dose-limiting toxicity. Rare, dramatic cases of peripheral neurotoxicity have been reported, also with features similar to Guillain-Barré syndrome (GBS). A 28-year-old man affected by T cell acute lymphoblastic leukaemia/lymphoma developed a severe neurotoxicity, after having being treated with nelarabine, obtaining a complete remission for a mediastinal relapse without bone marrow involvement. One month after treatment, he developed hypoesthesia in lower limbs and progressive gait imbalance: he was admitted to the Haematology ward. Haematologists decided to administer intravenous Immunoglobulin (IVIG), 0.4 mg/Kg per 5 days, in the hypothesis of a GBS. However, the clinical picture was not completely consistent with this hypothesis. There was mild bilateral inferior limb weakness, hypoesthesia with a L2-L3 sensory level bilaterally, increased deep tendon reflexes in lower limbs. Romberg’s signs was positive and gait imbalance worsened at eye closure. He underwent cerebrospinal fluid examination (mild hyperproteinorrachia, 52 mg/dL) with negative microbiological and virological tests. A nerve conduction study (NCS) was normal, except for mild conduction velocity

© 2014 Peripheral Nerve Society

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Del Sette M1 . 1 Department of Neurology, Osp. S. Andrea, La Spezia; 2 Laboratory of Neuroimmunology, ‘C. Mondino’ National Neurological Institute, Pavia; 3 Department of Neuroscience, University of Padova; 4 Department of Clinical and Experimental Medicine, Neurological Clinic, University of Pisa, Pisa; 5 Department of Nuclear Medicine, Osp. S. Andrea, La Spezia, Italy.

FOCUS THE GENETIC INVESTIGATION OF SPECIFIC GENES IN PATIENTS WITH STRICTLY LENGTH-DEPENDENT NEUROPATHY Balestrero R, Ursino G, Garnero M, Mandich P, Geroldi A, Capponi S, Reni L, Fabbri S, Grandis M, Bellone E, Schenone A. Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DiNOGMI), University of Genoa, Genoa, Italy.

Morvan’s syndrome (MoS) is a very rare disease that shows overlapping CNS and peripheral nerve hyperexcitability features, preferably with autonomic involvement. We describe a case of MoS with atypical EMG findings and abnormal cerebral FDG-PET. A 60-year-old man, who suffered from hypertension, prostatic hypertrophy and chronic obstructive pulmonary disease, presented with a 6-month history of pain and fasciculations in both lower limbs. Neurological examination revealed prominent fasciculations bilaterally in quadriceps femoris and gastrocnemius muscles. Deep tendon reflexes were brisk. Plantar responses were flexor. Muscle strength and sensory system were unaffected. Routine serum laboratory tests, which included TSH and autoantibodies, were normal, except for high creatine phosphokinase (909 IU/L). Cerebrospinal fluid analysis was normal, and oligoclonal bands were absent. ENG showed normal motor and sensory nerve responses. EMG disclosed fasciculations in gastrocnemius muscle bilaterally. Gabapentin (1200 mg/day) was administered without benefit. After 3 months, he presented generalized tonic-clonic seizures. EEG and brain MRI were normal. Lamotrigine (100 mg tds) was the therapeutic choice due to the concomitant neuropathic pain. After 6 months, the patient began sweating profusely, and had difficult sleeping, mild memory impairment, irritability were reported by his wife. Testing for paraneoplastic and autoimmune encephalitis antibodies resulted positive for anti-CASPR2 antibodies. EMG was unchanged, showing fasciculations, but not the typical doublets and triplets of spontaneous motor unit potentials (MUPs), trains of high frequency involuntary MUPs, and fibrillation potentials. Serum tumor markers, total body CT, and brain MRI were negative. Brain FDG-PET showed hypermetabolism in the left temporal region. Intravenous methylprednisolone (1 g/day for 5 days), followed by oral prednisone (75 mg/day) led to an improvement of pain and hyperhidrosis but the patient became increasingly disinhibited, irritable and aggressive so the therapy was stopped. Therefore he underwent 5 cycles of plasma exchange and 5 infusions of intravenous immunoglobulin (0.4 g/Kg/day) without improvement. A brain MRI control was still normal. Our case suggests that the diagnosis of MoS can be difficult when signs and symptoms of the disease manifest over time, and typical EMG features are lacking. On the other hand, the findings of pathogenetically-correlated anti-CASPR2 antibodies, which cause depolarization and muscle hyperactivity, and of the brain FDG-PET hypermetabolism, which can associate with encephalitis and epileptic activity, were fundamental for the diagnosis of MoS.

Charcot-Marie-Tooth (CMT) neuropathy is clinically and genetically heterogeneous. CMT patients may present with a length-dependent phenotype. Occasionally, impairment of the lower limbs in the absence of clinical and neurophysiological changes in the upper limbs may be observed. We evaluated the frequency of this unusual phenotype (which may be defined as a strictly length-dependent neuropathy) in the patients seen at our CMT clinic, particularly focusing on the correlation with mutations in specific genes. The patients were evaluated by full neurological, rehabilitative, neurophysiological examinations and routine laboratory testing to exclude acquired neuropathies. All patients were then tested for the following four genes: MPZ, GDAP1, HSPB1 and MFN2. 580 cases were present in the database. 56 cases fulfilled completely our selection criteria. 6 patients were excluded as the neurophysiological examination was not consistent with a peripheral neuropathy, 14 because the DNA was not available and 7 patients since a different diagnosis was performed (1 POEMS, 1 spastic paraparesis, 2 myopathies, 1 post-polio syndrome, 1 possible autoimmune neuropathy, 1 possible mitochondrial disease). Finally, in 6 patients genetic testing did not exclude a peripheral neuropathy (1 SMN2, 1 GNE, 3 SPG4, 1 DMPK ). In the remaining 23 patients, in relation to literature data and possible frequency, we tested four candidate genes (MPZ, HSPB1, GDAP1 and MFN2). All cases, except three, had a family history compatible with AD or AR inheritance. We found 5 mutations in two candidates genes: 3 MPZ (mean patients age 61 years) and 2 HSPB1 (mean patients age 33.5 years). No mutations in GDAP were found; MFN was negative in 10 patients and is currently under analysis in 13 more subjects. In all cases, the neurophysiological study was compatible with an axonal neuropathy (except in one case in which it showed both axonal and demyelinating changes). Our results show that a strictly length-dependent neuropathy is quite frequent (9.6%) in our population of patients. Among them, 41.6% were selected and tested for four candidate genes (MPZ, HSPB1, GDAP1 and MFN2). We found mutations in 21.7% of patients (13.04% MPZ and 8.69% HSPB1). Our results suggest that, in a strictly-length dependent, axonal and familiar neuropathy, the MPZ and HSPB1 genes should be tested first.

ATYPICAL ELECTROMYOGRAPHIC FEATURES AND FDG-PET HYPERMETABOLISM IN MORVAN’S SYNDROME Benedetti L1 , Franciotta D2 , Zoccarato M3 , Beronio A1 , Godani M1 , Schirinzi E1 , Siciliano G4 , Ciarmiello A5 ,

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by about 30% the islets amount to be co-transplanted, and that also reverses diabetic peripheral neuropathy and possibly relieves the related neuropathic pain. The study was conducted for two months after transplant; further studies are needed to extend the period of observation in order to determine the duration of these effects. This study was supported by MIUR (Firb Futuro in Ricerca 2008 Prot. N∘

EFFECTS OF ISLET TRANSPLANTATION AND MESENCHYMAL STEM CELL CO-TRANSPLANTATION IN THE PROTECTION OF DIABETIC NEUROPATHY IN STREPTOZOTOCIN-INDUCED DIABETIC RATS Bianchi R1 , Donzelli E2 , Rodriguez-Menendez V2 , Ballarini E2 , Monfrini M2 , Porretta-Serapiglia C1 , Bonandrini B3 , Canta A2 , Meregalli C2 , Oggioni N2 , Figliuzzi M3 , Remuzzi A3 , Lauria G1 , Cavaletti G2 , Scuteri A2 . 1 Neuromuscular Disease Unit, National Neurological Institute “Carlo Besta”, Milan, Italy; 2 Department of Surgery and Translational Medicine, University of Milan-Bicocca, Monza, Italy; 3 Department of Biomedical Engineering, IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Bergamo, Italy.

RBFR08VSVI-001).

IDIOPATHIC TRIGEMINAL SENSORY NEUROPATHY AND FACIAL ONSET SENSORY-MOTOR NEURONOPATHY (FOSMN). DO THEY SHARE COMMON PATHOPHYSIOLOGICAL MECHANISMS? Biasiotta A1 , Cruccu G1 , Pennisi EM2 , Antonini G3 , Di Stefano G1 , La Cesa S1 , Leone C1 , Raffa S4 , Sommer C5 , Truini A1 . 1 Department of Neurology and Psychiatry, Sapienza University, Rome, Italy; 2 Neurology Division, Neurosciences Department, San Filippo Neri Hospital, Rome, Italy; 3 Department NESMOS, Sant’Andrea Hospital, Rome, Italy; 4 Cellular Diagnostics Unit, Department of Clinical and Molecular Medicine, Sant’Andrea Hospital, Rome, Italy; 5 Department of Neurology, University of Würzburg, Würzburg, Germany.

Transplantation of pancreatic islets has been widely investigated as a strategy for blood glucose control in animals and in diabetic patients. Recently, we demonstrated that in vivo co-transplantation of mesenchymal stem cells (MSCs) and pancreatic islets is more effective with respect to pancreatic islets alone in ensuring glycemic control in diabetic rats. However, long-term diabetic complications, such as diabetic neuropathy, have not been explored in this setting. In the present study we investigated whether MSC/islet co-transplantation, with a reduced islet amount, ensured adequate islet function in rats with streptozotocin (STZ)-induced diabetes, and whether established complications like peripheral neuropathy regresses. Five groups of rats were used: a) healthy controls, b) diabetic rats, c) diabetic rats transplanted in the peritoneal cavity with microencapsulated syngeneic islets isolated from male Lewis rats (3000 islets/rat), d) diabetic rats transplanted (2000 islets/rat), together with 106 MSCs, e) diabetic rats intravenously injected with 106 MSCs. Islets were implanted two months after induction of diabetes, when established neuropathy was detectable by a decrease in nerve conduction velocity (NCV) and impaired nociceptive thresholds. At the end of the experimental period, group b) shows a marked hyperglycemia (+400%), a pronounced reduction in growth rate, a 26% and 76% decrease in NCV and mechanical sensitivity, respectively, and more than double time-latency for thermal sensitivity. The group MSCs injected (e) does not differ from the diabetic untreated group for any of the above parameters. On the contrary, both transplantation procedures (c, d) induced a significant reduction of hyperglycemia in more than 70% of the rats, followed by a gain of weight, that reached control values within 25 days. Among the parameters measured, NCV and Na,K-ATPase activity in the sciatic nerve were reduced by 25% and 34%, respectively, in diabetic rats, while co-transplantation restores quite completely NCV (7.5–10% of controls) and only partially Na,K-ATPase activity (27%). Thermal and mechanical sensitivity, respectively, increased 140% and decreased 76% in diabetic rats, co-transplantation progressively rescued thermal sensitivity and restored by about 50% mechanical sensitivity. In conclusion, these findings confirm that MSC co-transplantation not only ensures better glycemic control but was able to reduce

Idiopathic bilateral trigeminal hypoesthesia and pain might be the manifestation of an idiopathic trigeminal sensory neuropathy, a benign trigeminally-restricted disease, or the presenting symptom of the facial onset sensory motor neuronopathy (FOSMN), a seriously life-threatening condition. It is still unclear, however, which criteria may help to distinguish between the two conditions at their onset, and whether they are completely different diseases or share common pathophysiological mechanisms. In this clinical, neurophysiological and morphometric study we sought pathophysiological and diagnostic information to distinguish these two conditions at their onset. We neurophysiologically assessed function in myelinated and unmyelinated fibres and histologically examined supraorbital nerve biopsy specimens with optic and electron microscopy in 13 consecutive patients with recent onset of trigeminal hypoesthesia and pain. During a mean follow-up of 10 years while eight patients had relatively stable disease, five experienced progressive, possibly life-threatening motor disturbances and extra-trigeminal spread. From two to six years elapsed between the first sensory symptoms and the onset of motor disorders. Both in patients with idiopathic trigeminal sensory neuropathy and FOSMN neurophysiological and histological examination documented nerve damage selectively affecting myelinated fibres, but sparing the Ia-fibre-mediated proprioceptive reflex (i.e., a neuronopathy). Our study shows that in both conditions trigeminal nerve damage manifests as a dissociated neuronopathy affecting myelinated fibres and sparing unmyelinated fibres. The similar characteristics of trigeminal nerve damage in these two conditions raise the possibility that they might share similar pathogenetic mechanisms.

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DOES THE EPIDERMAL NERVE FIBRE DENSITY MEASURED BY SKIN BIOPSY IN PATIENTS WITH PERIPHERAL NEUROPATHIES CORRELATE WITH NEUROPATHIC PAIN?

pathway cause the onset of several neurodegenerative diseases of the central nervous system such as Parkinson’s or Alzheimer’s disease. The aim of this work is to investigate the involvement of Rab7 mutants causing CMT2B in the autophagic pathway. Control HeLa cells and HeLa cells expressing the Rab7 V162M mutant protein, control fibroblasts and fibroblasts from a CMT2B patient carrying the Rab7 V162M mutation were analyzed using several autophagy inhibitors. Western blot of autophagic markers after treatment with the drugs was performed to investigate possible alterations of the autophagic flux. In HeLa cells, no alterations of autophagy were detected, comparing control cells and cells expressing the Rab7 V162M mutant proteins, after treatment with wortmannin, a drug that inhibits the initial steps of autophagy. As expected, treatment of control cells with chloroquine, a drug that inhibits the maturation of autophagosomes in autolysosomes, results in a strong increase LC3-II, a well-known autophagy marker. Notably, we found that in cells expressing the Rab7 V162M mutant protein and treated with chloroquine, the abundance of LC3-II is instead much lower indicating an alteration of the autophagic flux. Similar results were obtained after expressing the Rab7 V162M mutant protein in Rab7-silenced HeLa cells. Furthermore, treatment of cells with other late autophagy inhibitors (pepstatin A, bafilomycin A1, E64D) fail to show any effect, indicating that the effect is restricted to chloroquine treatment. These results were also confirmed on human fibroblasts derived from a patient with CMT2B disease. Indeed, also in these cells, after treatment with chloroquine, LC3-II abundance was significantly lower than in control cells. Moreover, in order to study other aspects of vesicular traffic, we analyzed in these cells EGFR degradation demonstrating that this process is not impaired in CMT2B affected patient cells. We observed a strong difference between the abundance of the autophagic marker LC3-II in control cells and in cells expressing the Rab7 V162M, indicating that expression of the disease-causing mutant alters somehow autophagy. These data indicate a possible involvement of altered autophagic pathway in CMT2B disease.

Biasiotta A, Di Stefano G, Leone C, La Cesa S, Galosi E, Piroso S, Pepe A, Giordano C, Cruccu G, Truini A. Department of Neurology and Psychiatry, Sapienza University, Rome, Italy.

The different neuropathic pain types (e.g., ongoing burning pain and allodynia) are frequent and disabling complaints in patients with peripheral neuropathies. Although the reference standard technique for diagnosing painful small fibre neuropathies is nerve fibre density assessment by skin biopsy, the relationship between the epidermal nerve fibre (ENF) density and neuropathic pain is still unclear. In this clinical and skin biopsy study to investigate whether changes in ENF density are directly related to pain, we enrolled 139 consecutive patients with distal symmetric peripheral neuropathy. All patients underwent clinical examination, the Neuropathic Pain Symptom Inventory questionnaire to distinguish the different neuropathic pain types, and skin biopsy. ENFs were immunostained with the antiprotein gene product 9.5 and their linear density was quantified with bright-field microscopy. No difference was found in ENF density between patients with and without neuropathic pain, nor between patients with and without ongoing burning pain. Conversely, ENF density was higher in patients with provoked pains (including mechanical dynamic allodynia) than in those without. The variable association between ENF density and symptoms of neuropathic pain supports the idea that they arise through distinct underlying mechanisms. The lack of relationship between ongoing burning pain and ENF density suggests that this type of pain reflects factors other than loss of nociceptive afferents. The association between ENF density and provoked pain (including mechanical dynamic allodynia) suggests that this type of pain might be mediated by spared and sensitised nociceptive afferents.

DIAGNOSTIC SURPRISES WITH NERVE ULTRASOUND: 18-MONTH EXPERIENCE FROM ONE EMG/ENG LABORATORY

ALTERATIONS OF AUTOPHAGY IN CHARCOT-MARIE-TOOTH TYPE 2B DISEASE Bramato R1 , Manganelli F2 , Pisciotta C2 , Santoro L2 , Bucci C1 . 1 Department of Biological and Environmental Sciences and Technologies (DiSTeBA), Università del Salento, Via Provinciale Lecce Monteroni, Lecce, Italy; 2 Department of Neurosciences, Reproductive Sciences and Odontostomatology, University Federico II of Naples, Naples, Italy.

Cacciavillani M1 , Briani C2 . 1 CEMES – Data Medica Group, EMG Lab, Padova; 2 Department of Neurosciences, University of Padova, Padova, Italy.

Nerve ultrasound (US) is increasingly becoming a routine technique in neurophysiology labs for the information that can add to the classical electrodiagnostic (ENG-EMG) study. US examination provides anatomical information on nerve morphology and integrity, its relationship with the surrounding structures, and can also allow the direct location of nerve damage. We report the experience with US (ESAOTE MyLabOne) of our neurophysiology lab from August 2012 to January 2014. Out of 2671 patients evaluated with ENG-EMG, 1520 underwent also US evaluation. In

Charcot-Marie-Tooth type 2B disease (CMT2B) is caused by four missense mutations in the rab7 gene. Rab7 regulates transport to late endocytic compartments and, in the late steps of autophagy, the fusion between autophagosomes and lysosomes. Autophagy is a cellular process in which damaged proteins and organelles are delivered to lysosomes to maintain cellular homeostasis. Alterations of this

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effective on tactile allodynia threshold, glutamate release, astrocyte immunoreactivity and the expression of substance P, toll-like receptor 4, tumor necrosis factor-alpha, transforming growth factor beta-1, interleukin-1beta and translocator protein. These results suggest that testosterone metabolites are potential agents for the treatment of diabetic neuropathic pain.

particular, US was performed in all the cases of mononeuropathy, and in patients whose electrodiagnostic examination was doubtful or abnormal but did not allow the exact localization of the lesion. In 22 patients, US helped to solve diagnostic problems providing crucial information on the cause and site of neurological lesions. Of these 22 patients, 13 had median or ulnar nerve entrapment syndromes and one an ulnar nerve neurofibroma, all with negative ENG study. Of the patients with neurophysiological findings of equivocal interpretation, one turned out to have an ulnar nerve neuroma, and in 3 US helped identify the exact site of the lesion. Furthermore, US detected an accessory muscle at wrist, as well as the presence of a foreign body (namely a thorn) and a cyst in the hand that simulated carpal tunnel syndrome. Finally, in a patient complaining of sciatic symptoms, US revealed the presence of a huge aneurysm of the femoral artery. The results of our lab confirm the usefulness of US, as complementary to EMG-ENG, in the diagnostic process of mononeuropathies. The US “surprises”, besides allowing the identification of the nature and location of the neurological lesions, may help to choose targeted therapies.

OXALIPLATIN-INDUCED PERIPHERAL NEUROTOXICITY: RESULTS FROM A TWO-YEAR FOLLOW UP STUDY Campagnolo M1 , Bergamo F2 , Cacciavillani M3 , Dalla Torre C1 , Lucchetta M1 , Lonardi S2 , Briani C1 . 1 Department of Neurosciences, Neurology Unit, University of Padova, Padova; 2 Oncology Unit 1, Veneto Oncology Institute - IRCCS, Padova; 3 Data Medica Group, EMG Unit, CEMES, Padova, Italy.

Oxaliplatin (OXA)-induced peripheral neurotoxicity represents a dose-limiting adverse effect of chemotherapy, which can lead to severe disability. OXA may determine both acute and chronic neurotoxicity affecting a large group of patients, sometimes persisting for a long time or occurring after treatment withdrawal (coasting effect). Whereas several data are available on OXA neurotoxicity, little is known on the evolution of OXA-induced chronic neuropathy. The aim of our study was to evaluate the natural course and presence of residual neuropathy in patients treated with an OXA-based regimen. We convened in a control evaluation a cohort of 52 patients who had previously undergone capecitabine and OXA (XELOX protocol) therapy for metastatic colorectal cancer and had been prospectively neurologically (clinical evaluation with Total Neuropathy Score clinical version, TNSc) and neurophysiologically monitored from baseline to the end of therapy. Two years after OXA discontinuation, 17 (10 men, 7 women, mean age 61.7 yrs, range 40-70) of 52 patients were available for neurological evaluation. The presence and severity of neuropathy was scored with TNSc. Neurophysiological control was performed at the discretion of the physician provided that the patient was willing to do it. At enrollment, no patients had symptoms or signs of neuropathy. At the end of chemotherapy, in 10/17 patients TNSc worsened (median TNSc 5, range 3-8). At two-year follow up, all patients presented good oncologic response. Among the 10 patients who had developed OXA-induced neuropathy (median TNSc 5, range 3-8), 5 patients returned to baseline normal values, 2 patients remained stable (median TNSc at the end of OXA 3.5, median TNSc at follow-up 3), 3 patients showed an improvement in TNSc that however persisted >4 (median TNSc at the end of OXA 7, median TNSc at follow-up 4). Regarding neurophysiology, 9 of the 17 had evidence of sensory axonal neuropathy at the end of chemotherapy. At two year follow-up only 4 patients gave their consent to undergo neurophysiological examination, which was normal in 3 patients, while in the remaining patient documented a stable mild sensory axonal neuropathy. The preliminary results of our follow-up study show that, despite its frequency, OXA-induced peripheral neuropathy completely

DIABETIC NEUROPATHIC PAIN: A ROLE FOR TESTOSTERONE METABOLITES Calabrese D1 , Giatti S1 , Romano S1 , Porretta-Serapiglia C2 , Bianchi R2 , Milanese M3 , Bonanno G3 , Caruso D1 , Viviani B1 , Gardoni F1 , Garcia-Segura LM4 , Melcangi RC1 . 1 Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy; 2 Neuromuscular Disease Unit, IRCCS “Carlo Besta” Neurological Institute, Milan, Italy; 3 Department of Pharmacy and Center of Excellence for Biomedical Research, University of Genova, Italy; 4 Instituto Cajal, C.S.I.C., Madrid, Spain.

Diabetic neuropathy is associated with neuropathic pain in about 50% of diabetic subjects. Clinical management of neuropathic pain is complex and so far unsatisfactory. To this aim, in rats rendered diabetic by streptozotocin injection, we analyzed the effects of the testosterone metabolites, dihydrotestosterone (DHT) and 5alpha-androstane-3alpha,17beta-diol (3alpha-diol), on nociceptive and allodynia thresholds and on molecular and functional parameters related to pain modulation in the dorsal horns of spinal cord and in the dorsal root ganglia. Furthermore, the levels of DHT and 3alpha-diol were analyzed in the spinal cord. Diabetes resulted in a significant decrease in DHT levels in the spinal cord that was reverted by DHT or 3alpha-diol treatments. In addition, 3alpha-diol treatment resulted in a significant increase in 3alpha-diol in the spinal cord over control values. Both steroids showed analgesic properties on diabetic neuropathic pain, affecting different pain parameters and possibly by different mechanisms of action. Indeed, DHT counteracted the effect of diabetes on mechanical nociceptive threshold, pre- and post-synaptic components, glutamate release, astrocyte immunoreactivity and expression of interleukin-1beta, while 3alpha-diol was

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of lipid biosynthesis may result in abnormal myelin and PNS pathology. It has been recently shown that: i) the inherited neuropathy HSAN1 is caused by a gain of function mutation, which results in the formation of two atypical and neurotoxic sphingolipid metabolites; ii) diabetes-induced myelin abnormalities are associated with an altered lipid pattern; iii) aberrant Schwann cell lipid metabolism linked to mitochondrial deficits leads to axon degeneration and neuropathy; iv) the P0S63del mutation, causing CMT1B neuropathy, is associated with down-regulation of the lipid synthesis program. Moreover, we found in experimental models of CMT1A disease a striking reduction of genes primarily related to lipid metabolism and a significant reduction of sphingomyelin and cholesterol content which mirrors the dys-demyelinating phenotype observed in these models. Interestingly, the analysis of purified myelin from sciatic nerves of CMT1A rats showed that the decrease of lipids in pathological nerves is not merely due to the lack of myelin but also to an altered arrangement of these lipids in the myelin sheath. This prompted us to perform a lipidomic profiling in both the sciatic nerve and cerebrospinal fluid of 60-day-old CMT1A rats and wild type littermates. Due to the structural complexity of lipids and the low abundance of many lipid mediators, we carried out the analysis by both shotgun and targeted analysis using high resolution mass spectrometry (LC-MS/MS). In particular, by shotgun lipidomics, data were acquired over a broad mass range and analyzed altogether at the same time to capture the general picture of the metabolic profile of the samples. Collected data were then analyzed by multivariate data analysis tools such as Principal Component Analysis (PCA) to identify metabolic differences between the CMT1A and control group. In targeted analysis, we focused on the sphingomyelin pathway to clarify the critical step causing the significant reduction of this sphingolipid in experimental CMT1A. As the sphingolipid signal transduction pathway induces apoptosis, differentiation, proliferation, and growth arrest which have been shown to be involved in CMT1A pathogenesis, we are confident with this comprehensive study to improve our knowledge on the molecular mechanisms underlying this myelin disorder and to get insights which may contribute to the development of therapeutic approaches aiming at the preservation of myelin.

reversed in half of the patients after 2 years from OXA discontinuation, improved in one-third of the cases and persisted stable in 20% of the patients. The ongoing study on a larger population will help better clarify the long-term course of OXA-induced neurotoxicity. AGING ACTION ON PERIPHERAL NERVOUS SYSTEM IN C57BL/6 MICE: A MORPHOLOGICAL AND MORPHOMETRIC STUDY Canta A1 , Buccomino S1 , Carozzi VA1 , Meregalli C1 , Chiorazzi A1 , Marmiroli P1 , Lombardi R2 , Guido Cavaletti1 . 1 Department of Surgery and Translational Medicine, University of Milan-Bicocca, Monza (MB), Italy; 2 Neurological Institute “C. Besta”, Milan (MI), Italy. In the literature it is well known that aging influences several structural and functional features of peripheral nerves (Ceballos et al., 1999; Verdù et al., 2000; Jeronimo et al., 2008). However, the role of these changes in the damage/repair mechanisms occurring in acquired peripheral neuropathies is still unclear. For this purpose, a multimodal, long-term evaluation in an animal model would represent an optimal instrument to perform experimental neuropathy studies designed to assess the role of aging in relationship with a given nerve injury. In this study we used 66 female 4-week-old C57B1/6 mice and we followed them for sixteen months. Nerve conduction velocity (NCV) was assessed monthly in the caudal and digital nerves; moreover, four animals were sacrificed every two months and ventral caudal nerve, sciatic nerve, dorsal root ganglia (DRG) and skin were collected and processed for morphological and morphometric analysis. The neurophysiological studies evidenced a remarkable increase of caudal NCV until the age of 6 months and then it remained unchanged until the end of the study. Similarly, digital NCV increase was also observed even if less marked. At the pathological level, both caudal and sciatic nerves showed a decrease in fiber density related to age, whereas axon and fiber diameters tended to increase. DRG morphometric analysis evidenced an increase in somatic area and a mild reduction in nucleolus area in 15-month-old mice. Moreover, an age-related reduction in intraepidermal fiber density was also observed. These preliminary data can be considered a first step aiming at creating a background for future studies on the relationship between aging and peripheral nervous system induced damage.

SMALL HEAT SHOCK PROTEIN B8: AN ADDITIONAL GENE FOR DHMN WITH PREDOMINANT UPPER LIMBS INVOLVEMENT? Capponi S1 , Geroldi A1 , Ciotti P2 , Gulli R2 , Pazzaglia C3 , Padua L4 , Mandich P1,2 , Bellone E1,2 . 1 Departement of Neuroscience, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, Section of Medical Genetics, University of Genoa, Genoa; 2 IRCCS AOU San Martino-IST, UOC Medical Genetics, Genoa; 3 Don Gnocchi Foundation, Rome; 4 Institute of Neurology, Università Cattolica del Sacro Cuore, Rome, Italy.

EMERGING BIOLOGICAL ROLE OF LIPIDS IN PERIPHERAL MYELIN PATHOLOGY Capodivento G1 , Visigalli D1 , Basit A2 , Armirotti A2 Mancardi GL1 , Schenone A1 , Nobbio L1 . 1 Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal-Infantile Sciences and CEBR, University of Genoa; 2 Istituto Italiano di Tecnologia, Drug Discovery and Development Department, Genova, Italy.

The distal hereditary motor neuropathy (dHMN) type V is a pure motor inherited neuropathy characterized by the predominant involvement of the upper limbs (UL). It usually

Active myelination requires the high demand of lipid biosynthesis in Schwann cell processes, and the disruption

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presents weakness and wasting of thenar and first dorsal interosseous muscles, within the II decade. Some patients develop lower limbs (LL) weakness in later stages of the disease while the pyramidal tracts are rarely involved. The dHMN type V results from mutations in three different genes: Glycyl-tRNA synthetase (GARS), Berardinelli-Seip Congenital Lipodystrophy type 2 (BSCL2) and the recently identified Receptor Expression-Enhancing Protein 1 (REEP1). Herein, we describe an Italian family with a late onset dHMN. The clinical and electrophysiological features of the proband were consistent with a dHMN type V. The molecular analysis of GARS, BSCL2 exon 3 and REEP1 exon 5 were negative. In order to further explore the genetic defect underlying the dHMN type V phenotype in the family, we investigated other dHMN-associated genes. Interestingly, we identified the missense variant p.Arg78Met in the small Heat Shock Protein B8 gene (HSPB8). The variant segregated with the disease in six affected family members and was excluded in three familial healthy individuals. The variant was already reported in the 1000 Genomes EUR population, although with an extremely low minor allele frequency. The variant was therefore excluded in 250 matching normal controls. Moreover, it affected an amino acid conserved among evolution. On the other hand, the pathogenicity predictions studied, with specific bioinformatics tools, were conflicting. According to the wide intra-familial segregation, we are prone to consider the HSPB8 p.Arg78Met as a disease-causing mutation. The identification of additional dHMN families with the same substitution and specific in vitro studies will definitely clarify the role of the p.Arg78Met in the pathogenesis of dHMN type V.

tested in vivo neuroprotective properties of EQ through nerve conduction velocity (NCV) studies, morphological and morphometrical analysis of DRG, caudal and sciatic nerves and behavioral assessment of neuropathic pain. Cisplatin (i.p., 2 mg/Kg, twice weekly) and/or EQ (i.p., 75 micrograms/kg, daily) were administered in female Wistar rats for four weeks. When co-administered, EQ was injected 1 hour after cisplatin. A group of control animals was left untreated. At the third week of treatment, cisplatin alone determined piloerection, kyphosis and hypokinesia while co-treated animals had only piloerection. Neurophysiological measurements showed that cisplatin induced functional abnormalities in caudal nerve evident as a significant decrease in NCV (p < 0.001 vs. controls) while, if EQ was co-administered, the NCV impairment was significantly prevented (p < 0.05 cisplatin alone vs. cisplatin+EQ). Similarly, cisplatin-induced mechanical allodynia (p < 0.05 vs. controls) and thermal hypoalgesia (p < 0.01 vs. controls) were avoided when EQ was co-administered (p < 0.001 and p < 0.05 cisplatin alone vs. cisplatin+EQ for mechanical and thermal tests). Qualitative and quantitative analysis of DRG damage demonstrated that cisplatin alone induced somatic, nuclear and nucleolar atrophy in sensory neurons (p < 0.001 vs. controls for somatic, nuclear and nucleolar sizes); if co-administered with EQ atrophy was not observed (p < 0.001, p < 0.05 and p < 0.01 cisplatin alone vs. cisplatin+EQ for somatic, nuclear and nucleolar sizes). These data support the neuroprotective action of EQ against cisplatin-induced peripheral neurotoxicity and allow a future evaluation in tumor xenograft models of the interfering effects on the antineoplastic activity of platinum-based chemotherapy.

ETHOXYQUIN IS EFFECTIVE IN PREVENTING CISPLATIN-INDUCED PAINFUL PERIPHERAL NEUROPATHY IN RATS

PAINFUL SENSORY-MOTOR NEUROPATHY IN AN UNCOMMON TRANSTHYRETIN MUTATION GENE

Carozzi VA1 , Chiorazzi A1 , Marmiroli P1 , Oggioni N1 , Ceresa C1 , Zhu J2 , Hoke A2 , Cavaletti G1 . 1 Department of Surgery and Translational Medicine, University of Milan-Bicocca, Monza (MB), Italy; 2 Departments of Neurology and Neuroscience, Johns Hopkins School of Medicine, Baltimore, MD, USA.

Carpo M1 , Pareyson D2 , Piscosquito G2 , Del Bo R3 , Comi GP3 , Ferraro B1 . 1 UO Neurology-Stroke Unit, Az Ospedaliera Treviglio; 2 IRCCS Foundation, Ist. Neurol. C. Besta, Milan; 3 IRCCS Foundation Ca’ Granda, Osp. Maggiore Policlinico, Milan, Italy.

Ethoxyquin (EQ) is a synthetic potent antioxidant approved by the Federal Drug Administration for use in animal food in order to protect it against lipid peroxidation and stabilize fat soluble vitamins. It was found that diet supplemented with EQ allowed mice to live longer than littermates. Antimutagenic effect was observed in mice and rats treated with cancer chemotherapy. However, these observations were never carried out in human studies and the primary use of EQ is still as a supplement in animal food. EQ should be considered a potential neuroprotective drug against platinum-based chemotherapy, a cornerstone of the current antineoplastic treatment limited by the onset of peripheral nervous system dysfunction in cancer patients. In fact platinum-induced oxidative stress contributes to dorsal root ganglia (DRG) and peripheral nerve damage. Intriguing preliminary in vitro data demonstrated that EQ can prevent platinum toxicity on primary DRG culture. In this study we

Mutations of the transthyretin (TTR) gene induce an extracellular amyloid deposition predominantly in peripheral nervous system and/or heart. About 120 mutations in the TTR gene have been described and Val30Met is the most common mutation found in a large number of patients. Here we describe a 71-year-old man affected by chronic severe neuropathic pain associated with progressive weakness at lower limbs that had begun 3 years before. He was admitted to our department and underwent clinical examination, neurophysiological studies indicating a severe axonal-demyelinating sensory motor neuropathy. CSF protein level was moderately increased. A diagnosis of CIDP was considered and the patient treated by IVIg (0.4 g/Kg/day) for 5 consecutive days without benefit. During the 2 following years, because of the persistence of symptoms, the patient was admitted to another hospital and underwent several investigations. Since the clinical and instrumental findings confirmed the

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diagnosis of CIDP, the patient was treated with steroid ev without benefit and subsequently with 4 courses of IVIg with marginal improvement of neuropathic pain and weakness at the lower limbs. Unfortunately, during the last course of IVIg the patient developed rapidly progressive heart failure with left ventricular ejection fraction markedly reduced (25%). A cardiac MRI showed a previously unknown hypertrophic cardiomyopathy. His family history was negative for neuromuscular disorder or cardiomyopathy. The periumbilical fat biopsy did not show any amyloid deposition. A TTR gene molecular analysis detected the presence of heterozygous Tyr78Phe mutation. This TTR gene mutation had only been described in one patient with late-onset peripheral neuropathy and bilateral carpal tunnel syndrome and another one with predominant motor involvement. An atypical clinical presentation as CIDP-like phenotype has been previously described in Val30Met mutation. The discovery of the uncommon Tyr78Phe mutation in this atypical clinical presentation of amyloid neuropathy confirms the clinical heterogeneity of TTR amyloidosis. We suggest to consider TTR gene mutation analysis in all patients with chronic progressive peripheral nervous system involvement of late onset and in CIDP with no clear response to therapy.

actual communication with the artery. US diagnosis of pseudoaneurysm was made. Two weeks later, while the patient was on the surgery waiting list, sensory disturbances and weakness markedly improved, consistent with SCV normalization, motor CB resolution, reduction of pseudoaneurysm size (14 mm2 ) and different position of the nerve which was no longer compressed. Rare pseudoaneurysms of the ulnar artery are usually due to repetitive trauma and few cases are secondary to a single trauma not producing fractures or wounds. A post-traumatic micro-injury of the artery wall with hematoma in the surrounding parenchyma is hypothesized as the main pathogenetic mechanism of the delayed nervous damage in the current case. The spontaneous clinical improvement has been probably caused by partial rupture of the pseudoaneurysm, pressure reduction in the canal and rapid recovery of nerve functions impaired by the CB rather than by the axonal degeneration. We suggest that this rare condition, if not associated with HHS, should be EMG and US monitored before surgical referral.

SPONTANEOUSLY REVERSIBLE GUYON SYNDROME DUE TO ULNAR ARTERY PSEUDOANEURYSM

Cazzato D, Dalla Bella E, Dacci P, Mariotti C, Lauria G. 1 Neuroalgology and Headache Unit and 2 Clinical Pathology and Genetics Unit, IRCCS Foundation, “Carlo Besta” Neurological Institute, Milan, Italy.

CEREBELLAR ATAXIA, NEUROPATHY, AND VESTIBULAR AREFLEXIA SYNDROME: A SLOWLY PROGRESSIVE DISORDER WITH STEREOTYPICAL PRESENTATION

Casali S, Filippou G, Franci L, Ginanneschi F, Volpi N, Franci D, Giannini F. Dipartimento di Scienze Mediche, Chirurgiche e Neuroscienze – Università di Siena, Siena, Italy.

Cerebellar ataxia, neuropathy and vestibular areflexia syndrome (CANVAS) is a rare condition with adulthood onset, characterized by progressive impairment of cerebellar, vestibular and sensory functions leading to severe balance impairment. A syndrome characterized by late onset axial and limb ataxia due to bilateral vestibular deficit with cerebellar dysfunction was first described with the acronym of CABV (cerebellar ataxia with bilateral vestibulopathy). More recently, sensory or sensory-motor axonal neuropathy have been included to compose CANVAS. We describe four patients showing a similar clinical picture, characterized by slowly progressive ataxia and sensory disturbances in the feet as presenting features, evolving into severe balance dysfunction. Proprioceptive impairment along with cerebellar and vestibular dysfunctions were associated with gaze evoked horizontal or down-beating nystagmus, saccadic breakdown of smooth pursuit and abnormal oculo-cephalic reflex, also known as “doll’s eye” reflex. Otoneurologic examination demonstrated bilateral vestibular areflexia and impaired visual enhanced vestibulo-ocular reflex (VVOR), which are the prototypical changes in CANVAS patients. Brain MRI revealed vermian cerebellar atrophy. Nerve conduction study showed severe sensory neuropathy with non-length-dependent distribution and almost completely preserved motor nerve conduction. This pattern suggested that CANVAS may be associated with a primary sensory neuronopathy. Possible causes of predominantly sensory neuropathy such as inflammatory, autoimmune, vitamin deficiency, neurotoxic, metabolic or

Among several causes of ulnar nerve compression in the Guyon’s canal, true aneurysm, pseudoaneurysm or thrombosis of the ulnar artery are uncommon conditions. In many cases, symptomatic ischemia of fourth and fifth fingers occurs (hypothenar hammer syndrome, HHS). Anyway, based on EMG and imaging methods, early diagnosis and prompt surgical treatment are recommended. We report the case of ulnar artery post-traumatic pseudoaneurysm causing an acute Guyon syndrome. A 52-year-old man had been complaining for 3 weeks of weakness and tenderness of all ulnar supplied muscles of the left hand and tingling/hypoesthesia in palmar aspect of IV and V fingers, associated with painful non pulsating swelling in hypothenar eminence. No ischemic signs were observed in the hand. He reported a previous (4 months) hand trauma following a forward tumble. Motor nerve conduction study recording from FDI and ADM muscles showed: mildly reduced distal CMAPs and severe (97%) conduction block (CB) across the swelling. Sensory nerve conduction study showed reduced SAP/SCVs in IV and V finger-wrist segment. Mild denervation activity at rest and reduced interference pattern were detected at needle EMG. Electrodiagnosis of Guyon syndrome type I was made. The US examination showed an anechoic round-shaped formation (30 mm2 ) with sharp margins, adjacent to and partially wrapping the ulnar artery, and crashing the ulnar nerve against the bone profile. Doppler signal was poor, thus excluding

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immunoglobulin (IVIg) in the treatment of dysimmune chronic neuropathies. However, most literature data are still based on small single-centre studies. This nationwide multicentre study aims to investigate the clinical efficacy, side effects and quality of life in a large series of patients affected by CIDP and MMN shifted from IVIg to SCIg. We describe the results of a 4 month prospective trial including 87 patients affected by dysimmune polyneuropathies: 66 subjects were affected by CIDP and 21 subjects by MMN. All patients were diagnosed according to the EFNS/PNS diagnostic criteria and were previously treated with IVIg for at least 6 months, with clinical improvement. Patients were evaluated at T0 (shift from IVIg to SCIg) and at T1 (after 4 months of follow-up) by means of ONLS, MRC scale and LQI questionnaire. The group of CIDP patients showed a significant improvement in the ONLS score between T0 and T1, which ranged from 4.1 ± 2.8 to 3.1 ± 2.1 (P = 0.023). On the other hand no significant changes were observed at the MRC scale, which ranged from 70 ± 10.0 to 72 ± 10.4 (P = 0.3); several LQI scale sub-scores (I, II, III) showed a significant improvement between T0 and T1. MMN patient scores remained stable between T0 and T1, both for the ONLS (from 3.2 ± 1.6 to 3.5 ± 1.6; P = 0.6) and the MRC (from 73.3 ± 7.3 to 73 ± 7.9; P = 0.9). Moreover, no significant changes were observed in the LQI sub-scores. No subject was lost at follow-up and only minor side effects were observed in both groups, mostly represented by transient rush or edema in the site of injection. This study confirms the clinical equivalency of SCIg versus IVIg; moreover, the ONLS total score and several LQI scale sub-scores significantly improved in the group of CIDP patients after the shift from IVIg to SCIg. However, further studies are required to confirm the long term efficacy of SCIg and to evaluate whether this mean of immunoglobulin administration may have a different clinical efficacy in CIDP and MMN patients. The SCIg and Chronic Dysimmune Neuropathies Italian Network: R Fazio, A Toscano, S Pontecorvo, A Francia, G Antonini, A Clemenzi, M Filosto, R Liguori, A Clemenzi, AM Clerici, G Bono, G Siciliano, E Schirinzi, I Cecconi, M Suprani, P Valentino, R Nisticò, GA Marfia, G Mataluni, D Cocito, E Peci, A Merola.

paraneoplastic diseases were ruled out. Genetic disorders, such as dominant spinocerebellar ataxia and mitochondrial diseases characterized by cerebellar atrophy, sensory neuropathy and early ataxia, such as POLG1 and C10ORF2 mutations, were ruled out. Treatment with steroids and IVIG did not change the course of the disease in our patients. In conclusion, CANVAS should be suspected in patients with sensory neuropathy symptoms, early mixed ataxia and eye movement abnormalities suggesting cerebellar and vestibular dysfunction. BEYOND PERIPHERAL NERVE: SPINAL GLIOPATHY AND MALADAPTIVE SYNAPTIC PLASTICITY FOLLOWING PERIPHERAL NERVE INJURY Cirillo G1 , Todisco V1 , Tessitore A1 , Papa M2 , Tedeschi G1 . 1 Department of Medical, Surgical, Neurological, Metabolic and Aging Sciences, Second University of Naples, Italy; 2 Department of Public Clinic and Preventive Medicine, Institute of Human Anatomy, Second University of Naples, Italy. Peripheral nerve injury (PNI) represents a valid model to study both peripheral and central nervous system (CNS). Converging neuropathological evidence has well documented the modifications of a spinal nerve following an injury. However, the concept of the spinal glial reaction following PNI has emerged only recently. Glial cells in the CNS are more than brain glue: key components of the synapse (tripartite synapse), influence neuronal communication through the release of specific molecules (gliotransmitters), modulate synaptic transmission through the uptake/re-uptake neurotransmitter system, participate to ion homeostasis, and synapse formation. It is now well accepted that neuro-glia interactions are the basis for CNS synaptic plasticity (adaptive plasticity). When glial cells become activated, as in response to several peripheral or CNS insults, they undergo to specific phenotypic changes (hypertrophy and increased expression of glial fibrillary acidic protein - GFAP), determining structural and functional alterations of tripartite synapse that in turn impair the neuro-glial network function (maladaptive plasticity). This condition is called gliopathy, and is currently considered a “non cell-autonomous” mechanism for CNS disease onset and progression. Targeting reactive glial cells and glial-specific pathways might ultimately impact the development of therapeutic strategies for clinical management of “non-cell autonomous” processes.

SHORT-TERM EFFICACY OF PALMITOYLETHANOLAMIDE IN PERIPHERAL NEUROPATHIC PAIN Cocito D1 , Peci E1 , Ciaramitaro P2 , Cocito C3 , Merola A1 , Lopiano L1 . 1 Neurologia 2, 2 Neurochirurgia e 3 Dipartimento di Scienze Veterinarie, Università di Torino, Italy.

SUBCUTANEOUS IMMUNOGLOBULIN IS A SAFE AND EFFECTIVE THERAPY FOR CHRONIC DYSIMMUNE NEUROPATHIES: A NATIONWIDE STUDY

Palmitoylethanolamide (PEA) is an endogenous fatty acid amid that can inhibit the recruitment and activation of mast cells at sites of nerve injury, reducing the inflammatory reactions associated with peripheral neuropathic pain. In this study, we evaluated the clinical efficacy of PEA as an add-on treatment in patients with diabetic or traumatic neuropathic pain. 30 patients with chronic neuropathic pain were included and treated with 1200 mg/day of PEA for 40 days. Subjects were evaluated with VAS, Neuropathic Pain Symptom Inventory (NPSI), Health questionnaire five dimensions (EQ-5D),

Cocito D, Merola A, Peci E, Romagnolo A, Lopiano L; on behalf of the SCIg and Chronic Dysimmune Neuropathies Italian Network. Neurologia 2, Dipartimento di Neuroscienze dell’Università di Torino, Italy. Several clinical evidences suggest a clinical equivalency of subcutaneous immunoglobulin (SCIg) versus intravenous

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both at t basal evaluation and after 10 and 40 days of treatment. All other therapies were maintained stable during the follow-up period. Follow-up clinical data were available for 27/30 patients (20 diabetic neuropathy and 7 brachial plexus traumatic lesions). VAS mean score showed a significant improvement within the first 10 days, ranging between 8.2 ± 1.53 to 6.4 ± 1.83 (p < 0.002), with a further decrease to 5.8 ± 2.04 (p < 0.001) after 40 days of continuative oral PEA administration (T2). Moreover, NPSI total score improved from 0.52 ± 0.15 to 0.38 ± 0.21 (p: 0.025) and EQ-5D ranged from −0.3 ± 0.65 to 0.5 ± 0.34 (p < 0.001) between T0 and T2. This study reports the prospective short-term efficacy data of oral PEA treatment in patients with diabetic or traumatic neuropathic pain. We observed a significant improvement in both VAS and NPSI scores and in the quality of life scales after 40 days of treatment. Nevertheless, some limitations should be considered, including the short term follow-up and the open-label study design.

COMMON FIBULAR NERVE CONDUCTION BLOCK AT FIBULAR HEAD: CORRELATION BETWEEN NEUROPHYSIOLOGY AND ULTRASOUND Coraci D1 , Granata G2 , Tsukamoto H3 , Paolasso I4 , Padua L2,4 . 1 Board of Physical Medicine and Rehabilitation, Department of Orthopaedic Science, “Sapienza” University, Rome, Italy; 2 Institute of Neurology, Università Cattolica del Sacro Cuore, Rome, Italy; 3 Institute of Neurology, Teiko University, Tokyo, Japan; 4 Don Carlo Gnocchi Onlus Foundation, Milan, Italy. Common fibular mononeuropathy (CFN) is an important pathological condition often evaluated with neurophysiological examination. In addition, ultrasound (US) reveals its usefulness in the assessment of this disease because it is able to show the morphology of the damaged nerve. There is only a report comparing US and electrophysiological parameters in patients with CFN block at fibular head. We investigated the correlation between US and neurophysiologic findings in this condition. We retrospectively reviewed 24 patients with CFN assessed in our lab during the last two years. Each patient underwent clinical, neurophysiological and US evaluations. Cross sectional area (CSA) of CFN at fibular head was assessed. Motor nerve conduction study showed a reduction of distal compound muscle action potential (CMAP) amplitude in 10 patients (mean 1.3 mV). US showed an increased CSA in 10 patients. Statistical analysis revealed a strong correlation between the increased CSA and the CMAP reduction of CFN. The results of the current study show that US examination is normal in CFN conduction block at fibular head. However, the association with axonal damage is frequently accompanied by increased nerve CSA. The correlation between neurophysiology and US allows us to understand the nerve morpho-functional condition and may provide information for diagnosis and prognosis.

ALPHA-LIPOIC ACID IN THE TREATMENT OF ELDERLY PATIENTS WITH DIABETIC NEUROPATHIC PAIN Conti G, Bresolin N. Department of Neuroscience Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, “Dino Ferrari” Centre, University of Milan, Italy. Patients presenting with neuropathic pain are increasing in frequency as the population ages. New treatment options have recently been developed, and as clinicians we face a broader spectrum of efficacious therapy. For this reason, side-effect profiles play an important role in pain management. In diabetes, pain is associated with peripheral neuropathy, and occurs in one out of six patients. Treatment is based on four cornerstones; multifactorial intervention aimed to control glycemia and cardiovascular risk, treatment based on pathogenetic mechanisms, symptomatic treatment, avoidance of risk factors and complications. Since significant pain relief has been recently reported in diabetic patients using alpha-lipoic acid, we decided to treat with this compound 40 elder diabetic patients with neuropathic pain who in the past year had no relief with different drugs. Alpha-lipoic acid was administered at the dosage of 300 mg twice a day for one month and efficacy was measured by evaluation of pain scores, pain related sleep interference and Hamilton anxiety scale. 40% of the treated patients reported an approximately 2 point decrease in score of pain at the Likert scale, and amelioration in both sleep and anxiety. Among the refractory patients, 50% reported pain relief when pregabalin or duloxetine were added to alpha-lipoic acid while the remaining patients did not respond to any kind of management. No side effects have been reported to alpha-lipoic acid, while in the combination regimens side effects were related to the introduction of the second drug, but not severe enough to stop the treatment. In conclusion, alpha-lipoic acid shows efficacy on neuropathic pain relief and an extremely high tolerability, and it should be considered as an important option in the management of diabetic pain alone or in combination with other drugs.

CLINICAL AND DEMOGRAPHIC ASPECTS OF ATTR AMYLOIDOSIS: GENETIC HETEROGENEITY, PROGNOSTIC MARKERS AND NOVEL THERAPEUTIC APPROACHES Cortese A1 , Obici L2 , Palladini G2 , Milani P2 , Sforzini C2 , Perlini S3 , Verga L4 , Lavatelli F2 , Casarini S2 , Merlini G2 . 1 C. Mondino National Institute of Neurology Foundation IRCCS, Pavia, Italy; 2 Amyloidosis Research and Treatment Center, IRCCS Policlinico San Matteo, and Department of Molecular Medicine, University of Pavia, Italy; 3 Clinica Medica II, Department of Internal Medicine, Fondazione IRCCS Policlinico San Matteo and University of Pavia, Italy; 4 Department of Pathology, Fondazione IRCCS Policlinico San Matteo and University of Pavia, Italy. Hereditary transthyretin amyloidosis (ATTR) is characterized by high genetic and phenotypic variability, with differences in disease presentation and progression across different countries. Therapeutic resources are limited. We report longitudinal data of 14 years follow-up of patients affected by ATTR in Italy. 150 patients with ATTR amyloidosis were diagnosed and followed-up at the Amyloid Research and

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of IENF density. We recruited 11 patients aged between 29 and 77 years who were referred to our Institute to perform a diagnostic skin biopsy for suspected small fibre neuropathy. Skin biopsies were taken at the distal leg on the right and left side at the same time. Nine patients were diagnosed with small fibre neuropathy and 2 patients had normal IENF density compared with normative age and gender-adjusted values. Mean IENF density was 2.86 at right side (SD 1.46) and 2.72 at left side (SD 1.38). Values of IENF density at both right and left side were comparable and under the same cut off value for all patients. The correlation between right and left side was very high (Pearson coefficient 0.92). These preliminary findings demonstrate that IENF density at the distal leg does not vary between the right and the left side, leading to the same diagnosis in all the observed cases. A larger number of cases, including healthy subjects, is needed to confirm our observation.

Treatment Center, Pavia, between July 1999 and September 2013. They were investigated according to a standardized protocol including genetic testing, typing of amyloid deposits (immunohistochemical and/or proteomic assessment) and thorough clinical investigation. Patients were offered standard and experimental therapies. Mean age of onset was 63 (31-86) and male-to-female ratio was 3:1. A positive history was present in 45% of index cases. The mean delay to diagnosis was 34 months (12-96) and in 35% of cases the disease was initially misdiagnosed and unsuccessfully treated with steroids and immunoglobulins. At first examination, 64% of cases had heart and peripheral nervous system (PNS) involvement, 25% and 27% had isolated heart or PNS involvement, respectively. Orthostatic hypotension and diarrhea/vomiting were present in 30% of patients. Median PND score was 2 (0-4) and 25% of patients had already lost independent ambulation. Of note, 41% of patients had previously undergone surgery for bilateral carpal tunnel syndrome. Mutations in TTR detected in our cohort included Val30Met (25.5%), Glu89Gln (17.8%), Phe64Leu (12.1%) and Ile68Leu (10.2%) and 23 other mutations with lower frequency in the remaining 34.4%. Private mutations were identified in 9 subjects. Although Italy is considered a non-endemic area, over 50% of patients came from cluster areas in Sicily, Piedmont, Lazio and Emilia. 22 patients (14%) underwent liver or combined liver-heart transplant, 45 patients (29%) were treated with anti-amyloidogenic drugs including diflunisal, doxycycline-TUDCA, and tafamidis with promising results. Median survival from disease onset was 68 months, At Cox-multivariable analysis, the presence of Leu68 mutation, mLVW thickness >13.5 mm, mLVW thickness >13.5 mm and the presence of orthostatic hypotension were significantly associated with reduced survival. Mutated TTR amyloidosis shows high genetic and clinical heterogeneity in Italy. A sensory-motor peripheral neuropathy is the commonest presentation; however, one-fourth of patients presented with isolated cardiomyopathy. The disease is still largely misdiagnosed. Early diagnosis is essential to improve the care considering the availability of novel promising therapies.

HETEROZYGOUS D90A-SOD1 MUTATION IN A PATIENT WITH FACIAL ONSET SENSORY MOTOR NEURONOPATHY (FOSMN) SYNDROME: A BRIDGE TO AMYOTROPHIC LATERAL SCLEROSIS Dalla Bella E1 , Rigamonti A2 , Mantero V2 , Morbin M3 , Saccucci S3 , Gellera C4 , Mora G5 , Lauria G1 . 1 Headache and Neuroalgology, 3 Neuropathology and 4 Clinical Pathology and Genetics Units, IRCCS Foundation, “Carlo Besta” Neurological Institute, Milan, Italy; 2 Department of Neurology, “Alessandro Manzoni” General Hospital, Lecco, Italy; 5 IRCCS “Salvatore Maugeri” Foundation, Milan, Italy.

Facial onset sensory motor neuronopathy (FOSMN) syndrome has been recently described in patients with slowly progressive bulbar and upper limb amyotrophy. Sensory symptoms, mainly involving the trigeminal territory, typically precede the onset of motor weakness by months or years. We report the first case of FOSMN syndrome in a patient harboring D90A mutation in superoxide dismutase (SOD1) gene. A 53-year-old man presented with a 5-year history of tingling at lips and near the nose region. His familiar and personal history was unremarkable. Three years later, he had a significant weight loss, and reported generalized asthenia and weakness at upper limbs. Neurological examination showed absence of corneal reflex bilaterally, mild dysarthria, rhinolalia, hypotrophy and weakness of the tongue, diffuse fasciculations, predominantly proximal and asymmetric weakness at upper limbs, absence of deep tendon reflexes, normal superficial and proprioceptive sensation. Hematological exams revealed IgG-k MGUS. Cerebrospinal fluid examination, brain and spinal cord magnetic resonance imaging were unremarkable. Nerve conduction study showed reduced amplitude of sensory nerve action potentials in upper limbs alone with normal conduction velocities. Needle electromyography revealed acute denervation in upper limb and genioglossus muscles, and chronic neurogenic changes at all limbs. Cranial nerve neurophysiologic examination showed altered trigeminal-facial and trigeminal-trigeminal responses at blink reflex and jaw reflex recording, respectively, with normal

SKIN INNERVATION AT THE LEG: RIGHT TO LEFT VARIABILITY Dacci P, Lombardi R, Porretta-Serapiglia C, Dalla Bella E, Cazzato D, Lauria G. Headache and Neuroalgology Unit, IRCCS Foundation “Carlo Besta” Neurological Institute, Milan, Italy.

Skin biopsy with standardized quantification of intraepidermal nerve fiber (IENF) density at the distal site of the leg has become a diagnostic tool in clinical practice for the evaluation of painful neuropathy patients. Despite normative reference values are available, no study has systematically investigated the variability of IENF density between right and left side. This information would be useful both for diagnostic purposes in individual patients and for the use of skin biopsy as a biomarker of nerve regeneration in clinical trials, within the definition of the intrinsic potential variability

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is already a candidate marker for monitoring progression of small vessel vasculitis. The objective of this study was to assess whether plasma Pentraxin 3 (PTX3) levels might be an additional candidate marker for POEMS syndrome. Plasma PTX3 and serum vascular endothelial growth factor (VEGF) levels were measured (ELISA) longitudinally (mean follow-up 2 years) in 6 POEMS patients (4 men, 2 women, mean age 56 yrs, 42-70 range) and the results correlated with clinical course and therapy response. Sera from 16 age-matched patients with inflammatory or paraproteinemic neuropathies were used as control. PTX3 staining of sural nerve biopsies from patients with POEMS syndrome and vasculitic neuropathies were performed. Median plasma PTX3 level was 1.10 ng/ml (range 0.33–19.94, SD 3.40). Median serum VEGF level was 733 pg/ml (range 136–2679, SD 573.39). No statistic correlation was found between plasma PTX3 levels and VEGF serum levels in POEMS patients (p 0.17; r 0.19) or in controls patients (p 0.56; r 0.16). Sural nerve biopsies from patients with vasculitic neuropathy, but not those from POEMS patients, showed a strong PTX3 staining. Our data confirms VEGF as a very useful and more specific marker in the diagnostic and monitoring process of POEMS syndrome, also when compared to other markers of vascular inflammation/damage/injury, such as PTX3.

facial CMAP amplitude and latency. Motor evoked magnetic potential examination demonstrated normal central and peripheral motor conduction. Sural nerve biopsy demonstrated a mild loss of large size nerve fibers. Skin biopsy showed decreased intraepidermal nerve fiber density at the distal leg. Mutational assay of SOD1 gene identified a known nucleotide variant in heterozygosis causing aspartate-alanine substitution at codon 90 (pD90A). Several findings support the hypothesis that FOSMN syndrome is a primary degenerative disorder which widens the spectrum of motor neuron diseases. They include the anecdotal observation of TAR DNA-binding protein 43 inclusions in one patient, the disproportion between almost negligible sensory symptoms and progressive bulbar and upper limb muscle waste and weakness, and the dismal prognosis. Our finding of D90A-SOD1 mutation in a sporadic case presenting with clinical and neurophysiologic features of FOSMN syndrome strengthened the link with ALS. FOSMN should be considered a variant of ALS with slow progression and early sensory symptoms at face and upper limbs. The diagnosis should be considered in patients with bulbar amyotrophy and abnormal corneal reflex.

PENTRAXIN 3 AND VEGF LEVELS IN POEMS SYNDROME: A 2-YEAR LONGITUDINAL STUDY AND CORRELATION WITH NERVE PATHOLOGY

ULTRASONOGRAPHIC AND ELECTRODIAGNOSTIC CHARACTERISTICS ARE CORRELATED IN CIDP

Dalla Torre C1 , Cavallaro T2 , Ferrari S2 , Cabrini I2 , Lessi F3 , Scarlato M4 , Campagnolo M1 , Lucchetta M1 , Ruggero S1 , Toffanin E1 , Manfredi A5 , Morbin M6 , Lauria G6 , Ermani M1 , Adami F4 , Briani C1 . 1 Department of Neuroscience, University of Padova; 2 Neurological, Neuropsychological, Morphological and Movement Sciences, University of Verona; 3 Department of Medicine, Haematology Unit, University of Padova; 4 Division of Neuroscience, Department of Neurology & INSPE, San Raffaele Scientific Institute, Milan; 5 Department of Internal Medicine, San Raffaele Scientific Institute, Milan; 6 IRCCS Fondazione Istituto Neurologico “Carlo Besta”, Milan, Italy.

Di Pasquale A, Morino S, Saltelli G, Licchelli L, Antonini G. NESMOS Department, Clinic of Neuromuscular Disorders, University of Rome “Sapienza”, Italy.

Several MRI studies have demonstrated hypertrophy and abnormal enhancement of spinal nerve roots or brachial plexus in CIDP. More recently, nerve ultrasonography (US) has shown to be a promising diagnostic supportive tool for demyelinating neuropathy, but few data are still available on its diagnostic application in CIDP and there are only anecdotal reports on correlations between US and electrodiagnostic studies (EDX). In 2013 we started a blinded case-control study to evaluate the US nerve characteristics in CIDP and their correlations with NCS. According to the protocol, CIDP patients and age- and body-mass-index matched healthy controls are submitted, in the same day, to EDX and US study on median, ulnar and peroneal nerves, separately performed by two blinded neurologists (SM and ADP). For statistical analysis, nerve cross sectional area (NCSA) and nerve qualitative changes are recorded in the US study; motor nerve conduction and conduction blocks are recorded in the EDX. Here we present the correlations between US and EDX in 15 CIDP patients (11 males and 4 females, aged 28-78 years), which have been enrolled up to now. Disease duration at the time of the study ranged from 1 to 18 years (Mean 8 years; SD: 5.6). INCAT was 0-4. The US characteristics at each single nerve segment were compared with the EDX characteristics across the same segment. Because the entrapment sites were excluded from the analysis and ERB surface stimulation was considered unreliable for EDX, the correlation between

Polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes (POEMS) syndrome is a multisystem disorder associated with plasma cell dyscrasia. Elevated serum levels of vascular endothelial growth factor (VEGF), which strongly promotes neovascularization and vasopermeability, are considered to be responsible for many of POEMS syndrome’s symptoms, such as edema, pleural effusion/ascites, angiomata, organomegaly, and probably polyneuropathy itself. The insufficient clinical effects obtained by suppression of VEGF alone, as from using an anti-VEGF specific antibody (bevacizumab), suggests a more complex pathogenesis of POEMS syndrome. In order to explore other possible players, we focused on Pentraxin 3 (PTX3), a prototypic member of the long pentraxins family. PTX 3 is a multimeric glycoprotein acting as a soluble receptor with a non-redundant protective role against selected pathogens in innate response and playing a role in regulating inflammation through a cross-talk between innate immunity, extracellular matrix deposition and vascular biology. PTX3

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EDX and US was evaluated only for median and ulnar nerves at arm and forearm, for a total number of 120 nerve segments examined. According to EDX, 52 segments showed predominant myelin damage; their mean NCSA was 24.0 mm2 (SD: 23.8; 95% CI: 17.3-30.6). Twenty-five segments showed predominant axonal damage; their mean NCSA was 8.3 mm2 (SD: 3.9; 95% CI: 6.7-9.9). Forty-three segments had normal EDX; their mean NCSA was 8.4 mm2 (SD: 4.8; 95% CI: 6.9-9.9). NCSA of segments with EDX evidence of myelin damage was significantly higher than NCSA of segments with axonal damage and normal segments (One-way ANOVA; Post-Hoc Multiple Comparisons; p < 0.0001). Linear regression analysis showed that nerve conduction velocity was inversely correlated with NCSA only in those segments with EDX evidence of myelin damage (R2 : 0.40; p < 0.0001).

thrombosis, acute renal failure, stroke-like episodes and anaphylaxis, may occur but are rarely serious. Recently, the subcutaneous use of immunoglobulin (SCIg) showed the same ability to induce improvement and less adverse effects, besides improving the quality of life and reduce medication costs. We evaluated IVIG infusions performed at the outpatient service of the DiNOGMI from 2010 to 2013. In particular, we analyzed indication in neuromuscular diseases, incidence and type of AEs and therapeutic response, in 61 patients treated with IVIG. Response to IVIG was assessed by Medical Research Council (MRC) sum score and INCAT Sensory Sum Score, depending on the type of neuromuscular disorder the treatment was used for. Most patients were affected by CIDP (46%); 11.6% had myasthenia gravis, 10% had MMN and 28% had other neurological diseases (neuropathies not fulfilling the criteria for CIDP or MMN, possible motor neuron disease, myopathies or multiple sclerosis). Over a total of 227 infusions, AEs occurred in 7.9% of cases. Most AEs were mild, like headache (2.6%), transient hypertension (2.2%), hypotension and syncope (0.8%), fever (0.4%). Serious AEs were very rare and consisted in deep vein thrombosis (1 patient), haemolysis (1 patient) and delirium requiring hospitalization (1 patient). 72.6% of patients could be considered as responders to IVIG. Among these, 61% had CIDP and 31% needed at least three infusions/years. Most non-responder patients, after further testing, turned out to be affected by a neurodegenerative or inherited disease. IVIG are an important therapeutic and safe option in patients affected by neuromuscular diseases, especially CIDP with frequent relapses. As AEs confirm to be mild and not frequent, shift to subcutaneous infusion is not clinically indicated, unless in the presence of comorbidities which may predispose to severe side effects, particularly in patients requiring multiple infusions.

ULTRASOUND EVIDENCE OF CONCOMITANT TRAUMATIC NERVE LESIONS FAR FROM THE TRAUMA SITE Erra C1 , De Franco P1 , Briani C, Granata G1 , Paolasso I2 , Coraci D, Padua L1,2 . 1 Institute of Neurology, Università Cattolica del Sacro Cuore, Rome, Italy; 2 Don Carlo Gnocchi Onlus Foundation, Milan, Italy.

High-resolution ultrasound (US) of peripheral nerves is a valuable tool in the evaluation of traumatic nerve lesions. Sometimes in traumatic nerve lesions multiple site damages can be observed. The aim of this study was to identify cases of traumatic double site radial nerve involvement assessed through US. We evaluated 33 patients admitted to our neurophysiology lab from January 2010 to January 2014 for traumatic radial nerve lesions following humeral fractures. All the patients underwent clinical, electrodiagnostic and sonographic evaluation. In 17 patients a double site involvement of radial and posterior interosseous nerve was observed through US. Multiple site nerve lesions following a trauma can be suspected based on clinical evaluation (presence of non homogeneous motor or sensory deficit) but are difficult to demonstrate through electrodiagnostic tests. US can detect unexpected nerve impairment and help identify multiple site traumatic nerve lesions showing that they are often more frequent than we can imagine.

GENETIC HETEROGENEITY OF CMT2 AND DHMN Ferrarini M, Taioli F, Cavallaro T, Ferrari S, Cabrini I, Fabrizi GM. Department of Neurological and Movement Sciences, Section of Neurology, University of Verona, Italy.

The axonal form of CMT (CMT2) and the distal (hereditary) motor neuropathy (dHMN) are an heterogeneous spectrum of clinically and genetically overlapping disorders. They subtend high locus heterogeneity and the majority of the causal genes remain unknown; de novo cases, late onset and reduced penetrance complicate the recognition of a true hereditary neuropathy from an acquired disease (Rossor et al., Nat Rev Neurol 2013). Here we present a systematic molecular screening of CMT2 and dHMN in a large cohort of patients with definite or possible hereditary neuropathy referred to us for a molecular diagnosis. Molecular screening of known CMT2/dHMN genes (MFN2, MPZ, NEFL, GDAP1, GARS, YARS, HSPB8, HSPB1, DNM2, BSCL2, TRPV4, DCTN1) was performed by denaturing high performance liquid chromatography (DHPLC) and Sanger sequencing in more than 500 index patients. The role of detected mutations was investigated by looking up Ensembl and dbSNP databases, by interrogating bioinformatics tools

INTRAVENOUS IMMUNOGLOBULINS: USE AND ADVERSE EVENTS Fabbri S, Ursino G, Garnero M, Cabella I, Gemelli C, Schenone A, Grandis M. Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DiNOGMI), University of Genoa, Italy.

Intravenous immune globulins (IVIG) are biologic agents used to treat numerous neuromuscular disorders, such as Guillain-Barré syndrome (GBS), chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), myasthenia gravis and multifocal motor neuropathy (MMN). Adverse events (AEs), like hypotension, hypertension, deep venous

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were equally observed with each therapy. Two MMN and two CIDP patients increased the monthly dose for disease progression but this was not related to the change in IVIg. No variation in the MRC sumscore and in IVIg dose was observed in the other patients despite the change of IVIg. Chronic maintenance treatment with IVIg in our patients with MMN and CIDP was not associated with a different tolerability or efficacy despite the use of different brands of IVIg.

(PolyPhen-2, SIFT, Mutation Taster) and, in available families, by examining retrospectively the cosegregation in affected or healthy relatives by clinical and nerve-conduction tests. In our cohort, 79% of patients were referred as CMT2, 14% as pure dHMN, 7% as dHMN overlapping with CMT2. We identified 81 different mutations in 108 unrelated cases with an overall mutational yield of 16.3%. Seventy-one nucleotide variations were missense, the remaining were micro-indel, frameshift or splice-site mutations. Sixty-five mutations were clearly pathogenic based upon the adopted strategies and the analysis of intrafamilial cosegregation in 33 cases with ascertainable dominant inheritance: MFN2 20 mutations in 32 probands, MPZ 7 in 7, NEFL 8 in 11, GDAP1 6 in 6, GARS 5 in 8, YARS 2 in 2, HSPB8 1 in 1, HSPB1 7 in 7, DNM2 6 in 7, BSCL2 2 in 4, TRPV4 1 in 2. Sixteen mutations were possibly pathogenic and occurred in as many unrelated patients without other molecular lesions: MFN2 5 mutations, NEFL 5, GARS 3, DNM2 1, BSCL2 1, TRPV4 1. In conclusion, the molecular diagnosis of CMT2 and dHMN remains a challenging field. Because of the absence of easily recognizable phenotype-to-genotype correlations and of major causal genes besides MFN2 (which represents approximately 30% of cases), a gene-by-gene algorithm is time-consuming, cost-consuming and discouraging. Implementation of a disease-specific Next-Generation-Sequencing panel will represent a major breakthrough in the diagnosis. Nevertheless, deep genotyping will discover many variations with uncertain roles. Development of clinical and molecular databases and of easy functional tests in vitro may help to address the genetic heterogeneity of CMT2 and dHMN.

AUTOSOMAL RECESSIVE AXONAL NEUROPATHY WITH NEUROMYOTONIA DUE TO HINT1 GENE MUTATION Gandioli C1 , Taroni F2 , Milani M2 , Piscosquito G3 , Pareyson D3 , Moroni I1 . 1 Divisione di Neuropsichiatria Infantile, 2 SOSD Genetica delle Malattie Neurodegenerative e Metaboliche, 3 SOSD Clinica delle Neuropatie Degenerative Centrali e Periferiche, Fondazione IRCCS Istituto Neurologico C. Besta, Milano, Italy.

Autosomal recessive axonal neuropathy has been recently described in association with mutations in HINT1 gene, located on chromosome 5q31.1 and encoding histidine triad nucleotide-binding protein 1. The majority of the affected individuals carrying HINT1 mutations present with motor more than sensory axonal neuropathy in association with action myotonia at the hands and/or neuromyotonic discharges at needle electromyography (spontaneous high-frequency motor unit action potentials); cases suffering from a pure distal motor neuropathy have been recently reported as well. We screened for HINT1 mutations a series of 32 patients affected with sporadic or recessive axonal neuropathy (9 children and 23 adults). Clinical neuromyotonia was present in only two cases. A HINT1 mutation was found in one patient only, who carried the His112Asn substitution in homozygous form. The proband was a boy, now 22 yeard old, born to Italian consanguineous parents, presenting since the age of six years with progressive atrophy and weakness in distal lower limb muscles, associated with mild mental retardation. Clinical myotonia, characterized by percussion myotonia and slow and painful muscle relaxation after sustained contraction of the hands and of the proximal lower limb muscles, was observed at age 13 years. Electrophysiologic studies confirmed the presence of neuromyotonia associated with a severe predominantly motor axonal neuropathy. A previously described homozygous mutation (c.334C>A, p.His112Asn, Zimon et al., 2012) was detected in HINT1 gene; both parents and the healthy sister were heterozygous for the mutation, confirming autosomal recessive inheritance. He was treated with carbamazepine with partial benefit of myotonic symptoms but showed a progressive deterioration during the following years with severe weakness and atrophy at distal lower limbs and upper limbs involvement. The low detection rate of HINT1 mutations in our group of patients with recessive or sporadic axonal neuropathies suggests a low prevalence of HINT1 mutations in the Italian population compared to other case series previously described from other regions (particularly Eastern Europe). HINT1 is the only gene currently associated with axonal neuropathy and neuromyotonia and

EFFICACY AND TOLERABILITY OF DIFFERENT BRAND OF IVIG IN THE MAINTENANCE TREATMENT OF CHRONIC IMMUNE MEDIATED NEUROPATHY Gallia F, Balducci C, Di Pietro D, Nobile-Orazio E. 2nd Neurology, Department of Medical Biotechnology and Translational Medicine, Humanitas Clinical and Research Center, Milan University, Rozzano, Milan, Italy.

Treatment with high dose intravenous immunoglobulin (IVIg) is effective in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and multifocal motor neuropathy (MMN). Not all brands of IVIg are however licensed for their use in these neuropathies. We now analysed the efficacy and tolerability of different brands of IVIg in the maintenance treatment of CIDP and MMN. We reviewed the reports of six patients with CIDP and seven with MMN treated with IVIg from 2009 to 2013. Two patients with CIDP and two with MMN started ex novo their treatment while 9 continued the treatment initiated 2–169 months before (mean 45). In all patients we measured the MRC score in the six most affected muscles before each infusion, the monthly dose and brand of IVIg and adverse events. Patients were treated with IVIg for 25-60 months (mean 48) with a monthly dose of 70 g (range 20–160 g including starting dose). Patients were treated with IgVena, Gammagard, Kiovig and Flebogamma for a variable period of time. Minor and transient side effects

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has been reported in approximately 2/3 of patients (Zimon et al., 2012). Our results show the importance of looking for clinical and neurophysiological neuromyotonia in CMT patients to perform appropriate gene testing but also provide further evidence for genetic heterogeneity of this peculiar neuropathic phenotype.

both known risk factors for acute arterial hypertension, furthermore elevated levels of cytokines described in GBS can play a role in the pathogenesis of PRES by changing capillary permeability.

PERIPHERAL NERVOUS SYSTEM COMPLICATIONS OF CARDIAC SURGERY CORRELATION OF GUILLAIN-BARRÉ SYNDROME AND VARICELLA-ZOSTER INFECTION: DESCRIPTION OF TWO CASES

Gavazzi A1 , De Rino F1 , Dentali S1 , Picozzi A2 , Franceschi M1 . 1 Neurology Department, 2 Cardiology Department, Multimedica Hospital Castellanza (Va), Italy.

Garnero M, Ursino G, Fabbri S, Ferrara M, Tetarelli P, Viscoli C, Del Bono V, Reni L, Grandis M, Schenone A. Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DiNOGMI), University of Genoa, Italy.

We prospectively evaluated 245 consecutive patients from May to December 2013 who underwent cardiac surgery. Each patient had an interview and a neurological clinical examination during rehabilitation period. Patients with possible peripheral nervous system (PNS) complications underwent other examinations, particularly electrodiagnostic tests. Among 245 patients undergoing open heart surgery (coronary artery bypass grafting, valvular heart surgery, ascending aortic aneurysm repair), 15 (6.12%) developed the following 24 PNS complications: 3 brachial plexopathies, 3 carpal tunnel syndromes, 2 critical illness neuropathies, 2 worsening of signs or symptoms of pre-existing neuropathies, 2 involvement of X, 1 of IX and 1 of XII cranial nerves, 3 peroneal (at knee), 1 saphenous, 1 median (at Struthers ligament), 5 ulnar (at elbow) mononeuropathies. A preliminary analysis shows that diabetes is a strong risk factor for PNS complications (p = 0.007 at chi-square test), while we did not find any correlation with other clinical conditions, population data (gender, age) or type of surgical intervention. The mononeuropathies of right arms can be related to ipsilateral vein cannulation; position of body and stretching from chest wall retraction may be the cause of left arm mononeuropathies (more frequent); the use of saphenous vein and position of the limbs may be the cause of leg mononeuropathies; surgical and anesthesia procedures may injure cranial nerves. Careful preoperative assessment and careful postoperative management may reduce risk of long term neurological complications after cardiac surgery.

Guillain-Barré syndrome (GBS) is an acute, monophasic, immune-mediated peripheral neuropathy, usually preceded by an infective event. Among the many precipitants associated with GBS, the varicella-zoster virus (VZV) was rarely reported. A 47-year-old man displayed acute onset of paresthesia and weakness at lower limbs, and numbness at hands. A week before he had chickenpox. At neurological examination, the tendon reflexes were absent. The first spinal tap showed hyperproteinorachia (711 mg/L) and pleocytosis (40/mm3 ), the second one typical albumin-cytological dissociation (protein 2513 mg/L; cells 0.80/mm3 ). PCR for VZV was negative. Electroneurography evidenced a demyelinating neuropathy. Despite IVIG (0.4 g/Kg/day for 5 days) therapy, the course was rapidly progressive, as he presented dysphagia, facial palsy, tetraplegia and respiratory failure and underwent tracheostomy in the intensive care unit. After 21 days from IVIG, five sessions of plasmapheresis were administered with progressive clinical improvement. At 5 months, after a period of rehabilitation, the patient showed almost complete recovery, complaining only of acral painful paresthesias, alleviated by Gabapentin. A 42-year-old woman, six days after having suffered from chickenpox, showed acute onset of lumbar pain and global weakness. She underwent intravenous Acyclovir therapy, but after two days displayed bilateral facial weakness, dysphagia and dysphonia. Tendon reflexes were weak. Brain CT scan and electroneurography at the four limbs were negative. The spinal tap evidenced hyperproteinorachia (655 mg/L) without pleocytosis. During IVIG administration (0.4 g/Kg/day for 5 days), she had multiple episodes of high blood pressure, nausea and headache. She underwent brain MRI that showed signs of posterior reversible encephalopathy (PRES). She had no risk factors for PRES. After 15 days from IVIG, she gradually improved and was discharged to a rehabilitative department with only residual facial palsy and dysphagia. These cases suggest that primary VZV infection can be considered as a precipitating factor for GBS. From 1956, only 37 cases of GBS after VZV infection have been described. A causal mechanism might be a “molecular mimic”, as in other well-described associations. In the literature, very few cases of PRES in combination with GBS have been described. GBS and IVIG therapy are

GENOTYPE-PHENOTYPE CORRELATION IN TTR-FAP: DESCRIPTION OF A COHORT OF PATIENTS FROM SOUTH ITALY Gentile L, Russo M, Stancanelli C, Toscano A, Vita G, Mazzeo A. Department of Neurosciences, AOU “G. Martino,” Messina, Italy.

Transthyretin-related familial amyloidotic polyneuropathy (TTR-FAP) usually presents as a progressive sensorimotor polyneuropathy with severe autonomic dysfunction and cardiomyopathy. However, it is now known that clinical picture of TTR-FAP patients is widely variable and variation in the clinical presentation can occur between individual kindreds with the same mutation and even among family members. We collected data from 64 TTR-FAP patients followed since

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neuropathy, while seventy-one presented an axonal phenotype. The entire cohort was negative for 17p11.2 rearrangements. We studied nine different genes, namely PMP22, MPZ, GJB1, LITAF, MFN2, GDAP1, EGR2, LMNA A/C and SH3TC2. We identified mutations in eight different genes in sixty-four index cases. Among these, thirty-three had a demyelinating phenotype and thirty-one had an axonal one. This study shows MFN2 as the first autosomal dominant gene involved with a high percentage of de novo events. On the other hand, GDAP1 and SH3TC2 are the most relevant autosomal recessive genes, showing a very similar percentage.

1995 in our referral Centre for Neuromuscular Diseases. Our records include 24 unrelated families from South Italy harbouring three different mutations: Glu89Gln 32 patients (6 families), Phe64Leu 25 patients (15 families), and Thr49Ala 7 patients (3 families). Available patients underwent a series of regular follow-ups, including neurological examination, neurophysiological tests, cardiological evaluations, and cardiovascular autonomic tests. Glu89Gln was responsible for early cardiac involvement. A late onset of a slowly progressive disease which reached its terminal stage after about 10 years was observed in the Phe64Leu patients. Autonomic dysfunction was present in all three mutations but was more severe in the Thr49Ala. It is reasonable to consider Southern Italy as an endemic focus of TTR-FAP. An underestimation of disease prevalence could be caused by a late onset of FAP, which can manifest in patients up to their late 70s. Follow-up of asymptomatic individuals may permit the early detection of symptoms and signs, allowing a detailed record of the natural history of the disease from the beginning and facilitating prompt treatment.

ANTI-SULFATIDE IGM ANTIBODIES IN PERIPHERAL NEUROPATHY: TO TEST OR NOT TO TEST? Giannotta C, Balducci C, Gallia F, Di Pietro D, Nobile-Orazio E. 2nd Neurology, Department of Medical Biotechnology and Translational Medicine, Humanitas Clinical and Research Center, Milan University, Rozzano, Milan, Italy.

A GENETIC REVIEW OF A COHORT OF EARLY ONSET CHARCOT-MARIE-TOOTH DISEASE PATIENTS 1

1

3

3

Anti-sulfatide IgM antibodies have been associated with different forms of neuropathy and were variably associated with serum IgM monoclonal gammopathy and antibodies to the myelin-associated glycoprotein (MAG). This clinically heterogeneous association has induced some skepticism on the pathogenetic relevance of this reactivity. We reviewed the clinical association of high titers of anti-sulfatide IgM antibodies in patients with neuropathy and related disorders examined in our laboratory since 2004. The sera from 570 patients evaluated in our Institution for neuropathy or related disorders were tested for anti-sulfatide IgM antibodies by ELISA. After our previous report (Nobile-Orazio et al., 2008), sera were tested at the initial serum dilution of 1:32,000 and subsequently titrated by serial two-fold dilution. In all positive patients IgM antibodies to MAG were also measured and titrated by western blot. The data were correlated with the clinical and electrophysiological reports of the patients. High titers of anti-sulfatide IgM antibodies (1.32,000 or more) were found in 39 patients, including 19 patients with titers up to 1:64,000, and 20 with titers of 1:128,000 or more. In 33 of the 39 positive patients (85%), moderately (up to 1:25,600, 13 patients) or markedly (1:50,000 or more, 20 patients) increased titers of anti-MAG IgM antibodies were also found. In these patients the neuropathy had the typical features of a chronic demyelinating sensory ataxic neuropathy associated with anti-MAG antibodies. Six patients did not have increased titers of anti-MAG antibodies. Five of them had moderately increased anti-sulfatide titers (1:32,000 to 1:64,000) that were associated in one each with chronic sensory axonal neuropathy and IgG monoclonal gammopathy, POEMS syndrome, transthyretin associated amyloidotic neuropathy, minimal and asymptomatic neuropathy and paraneoplastic subacute sensory neuropathy. Only one patient with a demyelinating neuropathy associated with IgM monoclonal gammopathy had markedly increased anti-sulfatide titers (1:256,000). Increased titers of anti-sulfatide IgM antibodies are not infrequent in patients with neuropathy even

1

Geroldi A , Capponi S , Ciotti P , Gulli R , Pezzini I , Lamp M1 , Gotta F1 , Grandis M2 , Ursino G2 Schenone A2 , Reni L2 , Mandich P1,3 , Bellone E1,3 . 1 Departement of Neuroscience, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health - Section of Medical Genetics, University of Genoa, Genoa; 2 Departement of Neuroscience, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health - Section of Neurology, University of Genoa, Genoa, Italy; 3 IRCCS Azienda Ospedaliera Universitaria San Martino – IST National Institute of Cancer Research, Genoa, Italy.

Charcot-Marie-Tooth (CMT) disease is a clinical and genetic heterogeneous group of inherited peripheral neuropathies. CMT patients usually show disease onset in the second decade of life but cases with onset within the first decade are not rare. Literature data report more than 10 genes whose mutations are associated with inherited childhood peripheral neuropathies, mainly with autosomal recessive inheritance. However, mutations in autosomal dominant genes have been described, with a high frequency of de novo event. Although the number of genes involved is constantly increasing, they do account in a small percentage, making the molecular diagnosis extremely labor intensive. We have collected a cohort of 147 childhood onset (1st decade) neuropathies, both demyelinating and axonal. All patients were recruited through the Ambulatorio Integrato per la Diagnosi e Cura delle Neuropatie Ereditarie (IRCCS Azienda Ospedaliera Universitaria San Martino-Genova) or through the collaboration with other genetic or neurologic centres in Italy. The cohort was framed into different groups according to their clinical, electrophysiological and neuropathological features, in order to approach a targeted mutational analysis. Seventy-five patients were classified as demyelinating

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if they are often associated with a concomitant reactivity to MAG. A selective reactivity to sulfatide is rarely found and is associated with different forms of neuropathy indicating that testing for these antibodies may rarely help in the diagnosis of patients with neuropathy.

with controls, while IL-17 producing CD4+ T lymphocytes were increased in the group of “atypical” patients. Moreover in the group of patients with “atypical” phenotype we observed an increase of ROR 𝛾T expressing CD4+ T lymphocytes if compared with healthy subjects. Finally, the percentage of Blimp-1 expressing CD19+ B lymphocytes (plasma cells) was increased only in patients with “classical” phenotype if compared with controls. The hypothesis that different lymphocytes subset may be involved in different clinical phenotypes of IgM related neuropathy may explain the observation that patients with the classical phenotype generally improve after monoclonal antibody therapy specific for CD20 (Rituximab), while cases with atypical presentation often show good response to long-term corticosteroids therapy. However “population-based” studies are needed to definitively ascertain the role of the different lymphocyte subsets in the course of IgM neuropathy.

ULTRASOUND EVALUATION IN TRANSTHYRETIN-RELATED AMYLOID NEUROPATHY Granata G1 , Luigetti M1 , Coraci D2 , Del Grande A1 , Romano A1 , Bisogni G1 , Bramanti P3 , Rossini PM1,4 , Sabatelli M1 , Padua L1,2 . 1 Institute of Neurology, Catholic University of Sacred Heart, Rome, Italy; 2 Don Gnocchi Foundation, Milano, Italy; 3 IRCCS Centro Neurolesi Bonino-Pulejo, Messina, Italy.

Familial amyloid polyneuropathy is a rare condition caused by mutations of the transthyretin (TTR) gene. We assessed the pattern of nerve ultrasound (US) abnormalities in patients with TTR-related neuropathy. Seven patients with TTR-related neuropathy (TTR-N) and 5 asymptomatic TTR-mutation carriers (TTR-C) underwent neurological examination, nerve conduction studies, and US evaluation. Multifocal US abnormalities were identified in 6/7 TTR-N. A single patient with only a mild sensory polyneuropathy had normal nerves on US evaluation. In the TTR-C we only detected an enlarged ulnar nerve at the elbow. Interestingly, disease severity correlated with number of nerves affected on US evaluation. No specific pattern of US abnormalities was identified in this cohort. However, in TTR-related amyloid neuropathy, US may be a helpful tool in monitoring disease progression and/or clinical response to pharmacological treatment.

A NEW NAV1.7 SODIUM CHANNEL HAPLOTYPE ASSOCIATED WITH RESPONSIVENESS TO DULOXETINE: A PHARMACOGENOMICS STUDY OF NEUROPATHIC PAIN THERAPY Kapetis D, Pierro T, Galbardi B, Lauria GP. “Carlo Besta” Neurological Institute, Neuromuscular Diseases Unit, IRCCS Foundation, Milan, Italy.

Pharmacogenomics aim to study the inter-individual patient variability to drug response and efficacy by analyzing polymorphisms in relevant genes. Useful information could be obtained from genetic factors towards the choice of appropriate pharmacological treatment. In this work, we studied genotype-phenotype correlations of Nav1.7 sodium channel in neuropathic pain patients. The study involved 77 Italian patients treated with duloxetine and pregabalin. Nav1.7 exons were amplified by PCR with primers complementary to flanking intronic sequences. Calculation of pairwise linkage disequilibrium between single nucleotide polymorphisms (SNPs) and haplotype block partition analysis were carried out using Haploview software. SNP- and haplotype-trait associations were tested within the 5-kb block region of Nav1.7. Through PCR genotyping SCN9A gene a new haplotype has been detected consisting of two SNPs (rs9646771 and rs6432901) of the Nav1.7 gene. This haplotype was significantly associated through regression analysis (p-value 90%). F-wave inversion could be predicted only by DML and abnormal F-wave latency of the median nerve. Our study did not confirm the diagnostic usefulness of F-wave inversion

EPIDEMIOLOGY AND POTENTIAL PROGNOSTIC FACTORS IN GUILLAIN-BARRÉ SYNDROME: TEN-YEAR EXPERIENCE OF “POLICLINICO TOR VERGATA” Mataluni G, Rossi S, Rocchi C, Mangiardi M, Marfia GA. Institute of Neurology, Department of Systems Medicine, University of Tor Vergata, Rome, Italy. Guillain-Barré syndrome (GBS) is an acute immune-mediated peripheral neuropathy with a high variable clinical course and outcome. Despite immunotherapy, up to 20% of patients remain severely disabled and mortality in the first year is approximately 4%. The aim of this study is to perform an epidemiological analysis of clinical and electrophysiological features of patients admitted in our ward for GBS in the last ten years; to test the incidence of different GBS subtypes and their clinical and electrophysiological evolution; to test on our sample the prognostic value of variables known in the literature and our suggested integration with new prognostic markers. We collected data prospectively from 89 patients regarding: demographic features, previous infections, clinical manifestations, kind of therapy received, motor deficit and disability (evaluated respectively with MRC sumscore and GBS disability score (GBSDS)). We measured dosage of protein in the cerebrospinal fluid (CSF). Serial nerve conduction studies (NCS) were performed. Differences between groups were compared by Fisher’s exact test. Potential prognostic factors were tested in uni and multivariable logistic analysis and were estimated by regression analysis. 19% of GBS were acute motor axonal neuropathy (AMAN) and showed more severe prognosis.

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hobby), medical history (general anaesthesia, diabetes, renal failure, thyroid diseases, elbow and wrist fracture or trauma) and occupational biomechanical exposures (forceful work, repetitive elbow movement, fixed and forced elbow position, vibrating tools). The patients fill in also a hand diagram and self-administered questionnaire on symptom severity. The neurophysiologist calculates body and elbow anthropometric measures including the new obesity indexes (shape body index, waist-to-hip ratio) and scores clinical and electrophysiological UNE severity. Logistic regressions are used for calculating the odds ratios of potential risk factors. Our study seeks to show whether particular elbow dimensions in presence of specific work tasks and usual daily elbow positions can be associated with UNE and whether high or low BMI can be associated with different UNE aetiologies.

in the early stage of CTS. All F-wave parameters, including F-wave inversion, did not increase electrodiagnostic sensitivity and specificity and predictive values in CTS with respect to conventional neurographic methods. All F-wave anomalies depended on DML delay, CMAP amplitude reduction or axonal degeneration of motor fibres proximally to the entrapment site. F-wave inversion was present only if DML was delayed. One might wonder why the F-wave should be used in the electrodiagnosis of CTS when there are more sensitive and specific tests that measure directly the median nerve conduction across carpal tunnel.

ANTHROPOMETRIC, LIFESTYLE AND OCCUPATIONAL RISK FACTORS FOR ULNAR NEUROPATHY AT THE ELBOW: STUDY DESIGN Mondelli M1 , Aretini A1 , Ciaramitaro P2 , Coraci D3 , Greco G1 , Padua L5 , Rota E6 , Sicurelli F4 , Mattioli S7 . 1 EMG Service, Local Health Service 7, Siena; 2 Unit of Neurophysiology, Hospital CTO-Maria Adelaide, Torino; 3 Department of Orthopaedic Science, University of “La Sapienza”, Rome; 4 Department of Medical, Surgical and Neurosciences, University of Siena, Siena; 5 Department of Neurology, Catholic University, Rome and “Don Gnocchi Foundation”, Rome; 6 Neurology Unit, Hospital “G. da Saliceto”, Piacenza; 7 Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy.

SMALL FIBER INVOLVEMENT IN CMT1A Nolano M1 , Provitera V1 , Manganelli F2 , Pisciotta C2 , Iodice R2 , Stancanelli A1 , Saltalamacchia AM1 , Lullo F1 , Caporaso G1 , Santoro L2 . 1 “S. Maugeri” Foundation IRCCS, Center of Telese Terme (BN); 2 Department of Neurological Sciences, University of Naples “Federico II”, Naples, Italy. Sensory symptoms in CMT1A are generally attributed to large fiber dysfunction (loss of touch, vibration and position sense in the lower limbs). However, an involvement of small fibers has been recently brought up through findings from quantitative sensory testing (QST), laser-evoked potentials (LEP) and corneal confocal microscopy studies. It has been hypothesized that using adequate techniques, a more widespread involvement of somatic and autonomic small fibers could be documented in CMT patients. Based on this assumption, we performed an extensive clinical, morphological and functional study of cutaneous somatic and autonomic innervation in 10 patients affected by CMT 1A, in order to assess small fiber involvement in this condition. We used a dedicated questionnaire (SFN-siq) to investigate symptoms of small fiber impairment and QST to evaluate somatic C and A-delta fibers. The autonomic function was investigated using dynamic sweat test (DST) and SSR for sudomotor and Ewing tests for cardiovascular pathway. Morphological analysis on skin biopsies from distal leg included ENF density and sudomotor nerve assessment. Biopsies from 20 age- and sex-matched controls were used to compare patients’ morphological data while functional findings were compared with normative data from our laboratory. The SFN-siq revealed that all patients complained of at least 2 symptoms related to small fiber dysfunction. More frequently reported symptoms were paresthesias (80%), sweating disorders (60%), palpitations (50%) and gastrointestinal complaints (50%). Burning feet were present in 3 out of 10 patients. 9 out of ten patients had an increase in thermal/pain thresholds indicating an impairment of both C and A-delta fibers. DST revealed hypohidrosis in all patients (41.8 ± 22.8 vs. 83.7 ± 17.3 sweat drops/cm2 ). SSR amplitude at feet was significantly lower (p < 0.05) in patients compared to controls (1.6 ± 0.7 vs. 4.2 ± 3.2 mV). One patient showed a cardiac dysautonomia

Ulnar neuropathy at the elbow (UNE) is the second most common focal neuropathy, after carpal tunnel syndrome. Some studies showed association between UNE and male gender, elbow trauma, systemic disease (diabetes, hypothyroidism, renal failure), smoking, alcoholism, lower socio-economic status. A recent paper on occupational factor demonstrated that UNE was associated with forceful work but not with repetitive movements. The reports on BMI are contradictory: some authors did not demonstrate association with UNE; others showed relation with high and others with low BMI. There are no studies on the elbow anthropometric measures. The aim of this study is to evaluate the association between anthropometric, lifestyle and occupational risk factors with UNE. Here we report the design of this study. This is a multicentre, observational, case-control study. The sample size of cases and controls is calculated in at least 213 cases and 426 controls. The cases and controls aging between 14 and 70 years are enrolled among the patients sent to EMG labs of all participating centres by their doctors with an EMG request. The duration of case recruitment is one year. UNE diagnosis is made according to clinical and electrophysiological findings. The controls are patients admitted to the same EMG labs with upper limb complaints other than UNE. We exclude from cases and controls the patients with history of hereditary neuropathy, cancer in the previous 5 years, amyotrophic lateral sclerosis, C8-T1 radiculopathy and thoracic outlet, Guyon’s canal, carpal tunnel syndromes. Cases and controls fill in a questionnaire including queries on demographic data, handedness, lifestyle factors (smoking, alcohol consumption, fast weight loss, habit to keep the elbow in various positions, hand-arm intensive sport or

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with abnormalities in at least 2 tests, while 3 showed abnormalities in only one test. ENF density was significantly lower (p < 0.01) compared to age- and sex-matched control subjects. A significant loss (p < 0.001) of sudomotor nerves compared to controls was observed using both the pan-neuronal marker PGP and the selective cholinergic marker VIP. The density of both PGP-ir and VIP-ir sudomotor nerves, correlated with activated sweat gland density, with ENF density and with QST score (p < 0.01). Our findings confirm widespread small fiber damage in CMT 1A patients with a parallel involvement of autonomic and somatic nerve fiber subpopulations.

intra-nerve CSA abnormalities and roots CSA enlargement. In anti-MAG neuropathy patients, US revealed diffuse nerve alterations, regardless of disease severity or duration. The diverse US findings from CIDP might express the different pathogenic mechanisms and structural nerve changes of the different demyelinating neuropathies.

MOVEMENT ANALYSIS IN PATIENTS WITH CHRONIC IMMUNE-MEDIATED NEUROPATHIES IN IMMUNOMODULATORY THERAPY Paolasso I1,2 , Di Sipio E2 , Coraci D3 , Simbolotti C2 , Padua L1,2 . 1 Università Cattolica del Sacro Cuore, Roma; 2 Don Gnocchi Onlus Foundation, Centro S. M. Provvidenza, Roma; 3 Università La Sapienza, Roma, Italy.

NERVE US FINDINGS IN NEUROPATHY ASSOCIATED WITH ANTI-MAG ANTIBODIES Padua L1,2 , Granata G2 , Lucchetta M3 , Luigetti M1 , Coraci D4 , Campagnolo M3 , Dalla Torre C3 , Sabatelli M1 , Briani C3 . 1 Institute of Neurology, Catholic University of the Sacred Heart, Rome; 2 Don Carlo Gnocchi Onlus Fundation, Milan; 3 Department of Neurosciences, University of Padova, Padova; 4 Physical Medicine and Rehabilitation, Department of Orthopaedic Science, “Sapienza” University, Rome, Italy.

The response to immunomodulatory therapies and disease follow-up in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and multifocal motor neuropathy (MMN) are commonly evaluated examining muscle strength and disability. Clinical outcome scales are not sensitive enough to discriminate mild improvement in patient’s movements. Human motion analysis has been widely used in the evaluation of treatment and rehabilitation of neuromusculoskeletal diseases. Regarding polyneuropathies some papers have been published on gait analysis in CMT, but, to the best of our knowledge, no data are available on upper and lower limbs movement analysis in patients with immune-mediated neuropathies. The objective of this study is to evaluate the sensitivity of biomechanical measures in the evaluation of patients with CIDP and MMN in immunomodulatory treatment, in correlation with the clinical picture. Seven patients with chronic immune-mediated neuropathies (definite or probable MMN or CIDP) in IVIg treatment were enrolled. Muscle strength and disability were assessed with the Medical Research Council (MRC) sum score and the Overall Neuropathy Limitation Scale (ONLS). Motor tasks were recorded using the Smart D500 stereohotogrammetric systems, a piezoelectric force platform and a surface electromyographic system (sEMG). For each patient a minimum of two evaluations had been performed (pre- and post-IVIg treatment). Each patient performed finger abduction-adduction, flexion-extension and reaching-grasping tasks for upper limbs, linear walking and stabilometric evaluation for lower limbs. Upper limbs MRC score has been related with the relative task evaluating the range of motion (ROM). Lower limbs MRC score was related with the relative joint power peak. A total of 5 upper limbs analysis and 4 lower limbs analysis from 3 patients with CIDP and 4 patients with MMN were obtained. For upper limbs: in 2 patients motion analysis data reflected the clinical improvement; in 2 patients MRC score was stable while motion data showed mild worsening; in one patient MRC improved while motion analysis resulted stable. For lower limbs all motion data showed post-therapy improvement in power peaks and all MRC scores showed improvement or stability. Our preliminary results in a small sample of patients showed that 6/9 movement analysis results correlated with clinical behaviour. Follow-up studies will allow to ascertain whether

No nerve Ultrasound (US) studies have so far been performed in patients with neuropathy and anti-myelin-associated glycoprotein (MAG) antibodies. 28 patients (18 men, 10 women, mean age 69.2 ± 10.9 yrs; mean disease duration 6.9 yrs, range 1–28) with anti-MAG antibodies neuropathy underwent US evaluation at four limbs. All patients underwent widespread US evaluation using a US system equipped with a high-frequency broadband probe of up to 18 MHz. Echotexture and nerve cross sectional area (CSA) were assessed at distal and proximal sites at four limbs. Intra-nerve and inter-nerve CSA variability were also calculated. Patients with IgM paraproteinemic neuropathy without anti-MAG antibodies or with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) associated with IgM monoclonal gammopathy were also studied and the results compared. US findings were correlated with disease duration and clinical severity, as assessed with INCAT disability score. At clinical evaluation all patients with neuropathy and anti-MAG antibodies complained mainly of sensory symptoms. Eight of them presented also strength deficits. Median INCAT disability score was 2 (range 0-5). At US evaluation, 23/28 patients with anti-MAG antibodies neuropathy had increased CSA of at least one nerve outside of the entrapment sites. CSA intra-nerve variability was abnormal in 21/28 patients, in 14 of whom was secondary to an increase of nerve CSA out of entrapment sites. Inter-nerve CSA variability was abnormal in 16 patients, in half of whom for nerve CSA increase out of entrapment sites. Overall only one of the 28 patients with anti-MAG antibodies neuropathy had normal US findings. No correlation was found between US findings and INCAT score or disease duration. Patients with IgM paraproteinemic neuropathy without anti-MAG antibodies had similar CSA abnormalities. Instead 4/5 patients with CIDP and IgM monoclonal gammopathy presented higher inter- and

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the discrepancy between movement data and clinical picture, when present, might be predictive of disease evolution. Studies on a larger sample of patients will enable to see whether the motion analysis study may represent a sensitive outcome measure in immune-mediated neuropathies.

Bellone E1,2 . 1 Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health (DiNOGMI), University of Genoa, Genoa; 2 IRCCS Azienda Ospedaliera Universitaria San Martino, IST National Institute of Cancer Research, Genoa; 3 IRCCS G. Gaslini, Genova; 4 University of Napoli Federico II; 5 Azienda Ospedaliera SS Antonio e Biagio e C. Arrigo, Alessandria; 6 Azienda Ospedaliera S. Croce e Carle, Cuneo, Italy.

FOOT DROP AT ONSET IN SPINAL CORD MULTIPLE SCLEROSIS: EVIDENCE OF EARLY AXONAL DAMAGE Perozzi C, Lupidi F, Di Bella P, Provinciali L, Logullo F. Neurological Clinic, Ospedali Riuniti Ancona, Italy.

Ganglioside-induced differentiation associated-protein 1 (GDAP1) mutations are commonly associated with autosomal recessive Charcot-Marie-Tooth (AR-CMT2K) neuropathy; however, they also lead to autosomal dominant Charcot-Marie-Tooth (CMT2K). We aimed to investigate the frequency of autosomal dominant GDAP1 mutations in a cohort of Italian patients with axonal CMT. 109 axonal CMT patients, either with demonstrated autosomal dominant inheritance or isolated cases and representative of all Italian regions, were recruited. GDAP1 mutation analysis was performed by direct sequencing. Intragenic GDAP1 deletions were excluded using a Multiple Ligation Probe Assay. In seven CMT families (6.4%) we identified five pathogenic heterozygous GDAP1 mutations (p.Arg120Gly, p.Arg120Trp, p.His123Arg, p.Gln218Glu, p.Arg226Ser). Segregation of the mutation within the family was demonstrated in all cases. Disease onset in the affected individuals was variable between the first and the third decade. Disease progression was slow in most patients and overall severity was milder than typically seen in autosomal recessive GDAP1 mutations. Electrophysiological changes are heterogeneous but compatible with axonal neuropathy. With this study, we show that in our cohort of axonal CMT Italian patients, GDAP1 mutations represent the most common genetic defect compared with MFN2 and MPZ mutations (6.4% vs. 6.3% and 5.0%, respectively). The frequency of mutations in AD cases plus recessive cases, 7.0% in our series, makes GDAP1 the gene most frequently involved in axonal neuropathy in our population (13.4%). This suggests that a different molecular approach should be assessed on the basis of patients’ ethnic origin.

Axonal damage is the major determinant of functional disability in multiple sclerosis (MS), but its timing and extension is still debated. We describe a case of MS with unilateral foot drop at onset, with evidence of axonal loss on needle EMG, caused by a demyelinating plaque in the dorsal spinal cord. A previously healthy 44-year-old woman presented in November 2013 with acute right foot drop without pain or loss of sensitivity. On admission to our Clinic, neurological examination showed a severe weakness of all right extensor muscles of the foot and toes. Deep and superficial sensitivity were preserved. At first, electrophysiological findings seemed to be consistent with an acute L5 motor radiculopathy. In particular, motor and sensory nerve conduction studies were normal and a compressive peroneal neuropathy at the fibular capital was excluded. The F wave from the right peroneal nerve could not be elicited. EMG revealed an acute muscle denervation with spontaneous fibrillations and sharp waves at right peroneal, anterior tibial, toe extensor and flexor muscles. However, given the finding of a diffuse hyperreflexia at four limbs, the patient underwent spinal cord MRI that revealed a T2 hyperintensity lesion, with Gad-enhancement, in the anterior right side of dorsal spinal cord at D11-D12 level. A cerebral MRI showed bilateral demyelinating lesions on the periventricular white matter. An acute radiculopathy has already been described as presenting symptom in patients with MS, even if most of the cases reported in the literature are painful. Our patient presented with an acute motor painless motor deficit and spinal MRI showed a concordant demyelinating plaque. The needle examination highlighted signs of acute denervation compatible with an axonal injury with a myomeric distribution. Although it is not possible to discriminate whether axonal damage interests motor neurons in the anterior horn or L5 ventral root to its emergence from the spinal cord, the electromyographic findings allowed to demonstrate the presence of axonal loss at disease onset. Axonal damage in MS is present from the earliest stages of the disease and it is not just a late event following the demyelinating process.

ANALYSIS OF SCN9A AND SCN10A VARIANTS IN A COHORT OF 100 PAINFUL NEUROPATHY PATIENTS Pierro T, Lombardi R, Kapetis D, Lauria G. IRCCS Foundation, “Carlo Besta” Neurological Institute, Milan, Italy.

SCN9A and SCN10A encode the alpha subunit of Nav1.7 and Nav1.8 voltage-gated sodium channels, respectively, which are preferentially expressed in small diameter DGR neurons. Gain- and loss-of-function mutations in the SCN9A gene explained conditions at the edge of the spectrum of pain disorders, from inherited erythromelalgia (IE) and paroxysmal extreme pain disorders (PEPD) to congenital insensitivity to pain (CIP), respectively. Nav1.8 and Nav1.7 interact each other and changes in their expression level and function may affect the excitability of nociceptors.

AUTOSOMAL DOMINANT MUTATIONS IN GDAP1 ARE A FREQUENT CAUSE OF AXONAL CHARCOT-MARIE-TOOTH DISEASE IN ITALIAN PATIENTS Pezzini I1 , Capponi S1 , Geroldi A1 , Ciotti P2 , Gulli R2 , Doria Lamba L3 , Manganelli F4 , Grandis M1 Cremonte M5 , La Piana C6 , Santoro L4 , Schenone A1 , Mandich P1,2 ,

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We describe novel pathogenic Nav1.7 and Nav1.8 mutations in a cohort of painful predominantly small fibre neuropathy (SFN) patients. DNA was extracted from blood and amplified by PCR. Sequences were analyzed by SeqScape Software. Each variant was assessed in 300 blood donors. SCN9A analysis: one patient harboured 1964A>G (K655R) mutation, previously described in association with febrile seizures. This mutation causes an amino acid substitution into a highly conserved intracellular loop. The 2215A>G (I739V) mutation, previously profiled as gain-of-function by current and voltage clamp assays, was found in the index case, the sister and the asymptomatic mother. Three mutations (2794A>C M932L; 2971G>T V991L; 4612T>C W1538R) were identified in two patients. Two of them (M932L+V991L) were previously found in two SFN patients and their pathogenicity demonstrated by voltage and current-clamp assay. W1538R, previously associated with IE and CIP, maps on the fourth sodium channel domain in the second transmembrane segment and revealed gain-of-function properties. One patient was heterozygous for the 3799C>G (L1267V) previously associated with Dravet syndrome. SCN10A analysis: we recently found the 1661T>C (L554P) gain-of-function mutations in one patient with diabetic painful neuropathy and his non-diabetic father with SFN. Its pathogenicity was demonstrated by voltage and current-clamp assay. We report seven novel SCN9A and SCN10A mutations, which were found to induce pathogenic variations in the sodium channel and to affect its function. Our findings broaden the spectrum of channelopathy-associated painful neuropathies and support the view biophysical property changes may lead to different clinical phenotypes. SCN9A and SCN10A gene variants influence the susceptibility to pain and cause painful neuropathy.

these changes. In humans, NAC did not change the thermal-pain perceptive thresholds as assessed by quantitative sensory testing, but reduced the laser pain ratings and the amplitude of laser evoked potentials (P < 0.05). In mice, NAC inhibited tail flick (P < 0.05), and this inhibition was prevented by a single injection of the mGlu2 receptor antagonist, LY341495. Our findings, showing that NAC reduces the laser pain ratings and the amplitude of laser-evoked potentials, indicate that NAC inhibits nociceptive pathway function in humans. In animals, the block of NAC-induced changes of tail flick by LY341495 indicates that the NAC-induced nociceptive pathway modulation is mediated by mGlu2 receptor. Our study suggests that NAC is worthy of being tested in a clinical trial in patients with pain.

REDUCED NEUROFILAMENT EXPRESSION IN CUTANEOUS NERVE FIBERS OF CMT2E PATIENTS Pisciotta C, Bai Y, Brennan K, Grider T, Feely S, Wang S, Moore S, Shy M. University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA.

The objective of this study is to investigate the effects of NEFL Glu396Lys mutation on the expression and assembly of neurofilaments (NF) in cutaneous nerve fibers of CMT2E patients. CMT2E patients are heterogeneous and different NEFL mutations lead to distinct pathological effect. Previous studies have demonstrated accumulations of NF in the cell body in transgenic mouse models of CMT2E with a concomitant defect of the NF network resulting in the absence of axonal NF. Presumably, because accumulations are proximal, sural nerve biopsies from patients with NEFL Glu396Lys mutation have not demonstrated aggregates despite the presence of axons devoid of NF. All affected members of a large CMT2E family underwent clinical, electrophysiological and skin biopsy studies. Biopsies were processed either by indirect immunofluorescence or by electron microscopy. The clinical features demonstrated intra-familial phenotypic variability and the electrophysiological findings revealed nerve conductions that were either slow or in the intermediate range. All patients had reduced or absent CMAP amplitudes. Skin biopsies demonstrated variable reduction of axonal fibers. Interestingly, many axons were labeled with the axonal marker PGP 9.5 but were not labeled by antibodies to NF, unlike what we observed in controls. Electron microscopy revealed clusters of regenerated fibers and bands of Bungner, in absence of significant myelin sheath abnormalities. Both immunohistochemistry and electron microscopy failed to show NF aggregates in dermal axons. Correlations between neuropathological results and clinical severity are underway. Decreased immunolabeling of axons by antibodies to NF may be an early marker of axonal degeneration in CMT2E. The lack of NF aggregates is consistent with prior studies suggesting that such aggregates occur proximally, leading to subsequent alterations in the axonal cytoskeleton. Our results also demonstrate that skin biopsy can provide evidence of pathological and pathogenic abnormalities in patients with CMT2E.

N-ACETYL-CYSTEINE INHIBITS NOCICEPTIVE PATHWAY FUNCTION. A TAIL FLICK STUDY IN MICE AND DOUBLE-BLIND, PLACEBO-CONTROLLED STUDY OF QUANTITATIVE SENSORY TESTING AND LASER EVOKED POTENTIALS IN HUMANS Piroso S, Biasiotta A, Nicoletti F, Pasquale E, Truini A. Department of Neurology and Psychiatry, Sapienza University, Rome, Italy.

Previous studies showed that N-Acetylcysteine (NAC), the old and safe drug used as a mucolytic agent, causes analgesia in animal models of chronic pain, possibly by reinforcing the endogenous activation of type-2 metabotropic glutamate receptors (mGlu2 receptors). In this study, we aimed at testing whether NAC inhibits nociceptive pathway function in humans, and then verifying in animals whether this NAC-induced inhibition is mediated by mGlu2 receptors. In 10 healthy humans we have measured changes induced by 1200 mg of oral NAC on nociceptive pathway-mediated quantitative sensory testing and laser evoked potentials, according to a cross over, double-blind placebo-controlled design. Then we have investigated the NAC-induced changes in tail flick evoked by heat stimulation in 6 mice, testing whether LY341495 (mGlu2 receptor antagonist) prevented

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PURE SENSORY NEUROPATHY AS LONG-LASTING ISOLATED MANIFESTATION OF POLG1-RELATED DISORDERS

SUBCUTANEOUS INFUSION OF HUMAN IMMUNOGLOBULINS IS EFFECTIVE FOR TREATMENT OF PAINFUL DIABETIC POLYNEUROPATHY: A CASE REPORT

Piscosquito G, Salsano E, Lamantea E, Rossi Sebastiano D, Lamperti C, Pareyson D. IRCCS Foundation, C. Besta Neurological Institute, Milan, Italy.

Plasmati R, Pastorelli F, Michelucci R. UOC Neurologia, IRCCS Istituto delle Scienze Neurologiche, Bologna, Italy.

A 60-year-old man with insulin dependent diabetes mellitus developed severe neuropathic pain. He presented with burning paraesthesia and marked allodynia at upper limbs and chest, so that he could hardly tolerate the touch of clothes on his skin. Antiepileptic drugs and amitriptyline were ineffective. Neurologic evaluation showed hyposthenia of foot dorsiflexion, sensory hypoesthesia with sock and glove distribution, hypopallesthesia at lower limbs and diffuse dolorific dysesthesia with tactile allodynia. Deep tendon reflexes were diffusely reduced. Electrodiagnostic studies showed sensorimotor axonal and demyelinating polyneuropathy, with reduction of SAP and cMAP amplitudes, reduced sensory and motor conduction velocities and prolonged F wave latencies at four limbs. The patient was treated with intravenous immunoglobulin (IVIG) infusions, 0.4 gr/kg for five days: hyposthenia and neuropathic pain improved significantly. The treatment was repeated (0.4 gr/kg for three days every month) with complete and persistent remission of pain and transient improvement of hyposthenia following each treatment. Being the patient is a freelance, travelling abroad many times a year, subcutaneous immunoglobulin (SCIG) infusion was considered as the best treatment choice. For this reason, the patient was switched to weekly 20% SCIG (Hizentra®; CSL Behring) infusions at doses equivalent to his previous IVIG treatment. The disease remained stable and no serious adverse events were reported. Peripheral neuropathy associated with diabetes mellitus often causes severe neuropathic pain that is difficult to alleviate. Pain associated with diabetic neuropathy is multifactorial and causative factors are heterogeneous. It is well known that IVIg may reduce pain and improve motor function in diabetic polyneuropathy, multiple neuropathy and lumbosacral radiculoplexus neuropathy. However, a chronic hospital-based IVIG treatment can hamper the patient’s working life as well as general quality of life. We suggest that SCIG infusions can be an effective and safe solution for patients with painful diabetes-related neuropathy.

POLG1 mutations result in highly heterogeneous phenotypes that often have overlapping clinical findings. Ptosis associated with ophthalmoparesis (PEO) is the most frequent clinical presentation in adults and often associated with diffuse myopathy. Ataxia neuropathy spectrum (ANS), including MIRAS (MItochondrialRecessive-Ataxia-Syndrome) and SANDO (Sensory-AtaxiaNeuropathy-Dysarthria-Ophthalmoplegia) are also common, whereas only in one family a CMT-like presentation was described (Harrower et al., Ann Neurol, 2008). We report three patients (2 females; age 40-69 years) with POLG1 mutations, in whom sensory neuropathy was the onset manifestation and remained the only disease expression for a long time (13-30 years). All patients complained of paresthesias in lower limbs and two (Pt2, Pt3) had also mild-to-moderate balance difficulties. Clinical examination showed: isolated moderate sensory neuropathy without ataxia (Pt1); moderate ataxic gait, severe deep sensation and pain/touch impairment (Pt2, Pt3). Notably, Pt3 had also mild motor involvement with pes cavus (CMT2-like phenotype). Nerve conduction study showed severe sensory nerve action potential amplitude (SAP) reduction in Pt1, while in Pt2 and Pt3 SAPs were absent. Only Pt3 had mild reduction of compound motor action potential amplitudes, while motor conduction velocities were normal in all the subjects. In Pt2 and Pt3, somatosensory evoked potentials were absent from all limbs, and in Pt1 the N22-P37 interval was markedly prolonged. The other multimodal evoked potentials were normal in all subjects. Brain MRI showed minimal cerebellar atrophy only in Pt3. Cervical spinal cord MRI demonstrated posterior column T2-hyperintesity in Pt1 and Pt3. Muscle biopsy showed mild-to-moderate mitochondrial alterations including COX-negative fibres and/or Ragged Red Fibers in all patients. We identified a POLG1 recessive mutations in all patients: Pt1 was homozygous for in cis p.Thr251Ile/p.Pro587Leu; Pt2 was compound heterozygous for p.Arg562Trp and p.Ser1201fs*23; Pt3 was compound heterozygous for p.Pro753Leu and p.Arg807Pro. Sensory neuropathies are known to occur in patients harboring dominant and recessive POLG1 mutations, often causing profound sensory ataxia; however, the neuropathy is never isolated, but associated with additional neurological features, clearly suggesting the diagnosis of a mitochondrial disorder (MD) (Horvath et al., Brain, 2006). By contrast, two of our patients (Pt1, Pt2) had an isolated pure sensory neuropathy for over 2 decades, and sensory ataxia became manifest only later in the disease course, without ophthalmoplegia or other signs that characterize the well-described MD. This report further widens the phenotypic spectrum of POLG1-related disorders, which includes for the first time pure isolated sensory neuropathy. Furthermore, we confirm that MDs may present as CMT2 (Pt3).

L-SERINE SUPPLEMENTATION IMPROVES DEFINED NEUROPATHY IN A TYPE 1 DIABETIC RAT MODEL Porretta-Serapiglia C1 , Othman A3 , Chiorazzi A2 , Meregalli C2 , Oggioni N2 , Cavaletti G2 , Lauria G1 , Hornemann T3 , Bianchi R1 . 1 Headache and Neuroalgology Unit, IRCCS Foundation “Carlo Besta” Neurological Institute, Milan, Italy; 2 Department of Neuroscience and Biomedical Technologies, University of Milan Bicocca, Italy; 3 Institute for Chemical Chemistry, University Hospital Zurich, Zurich, Switzerland. 1-Deoxysphingolipids (1-deoxySL) are atypical sphingolipids which lack the C1 hydroxyl group of normal sphingolipids and are therefore not converted into complex

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sphingolipids or degraded by the normal catabolic pathway. They are formed by the enzyme serine-palmitoyltransferase (SPT) due to a promiscuous use of L-alanine over its canonical substrate L-serine. Several missense mutations in SPT lead to the pathologically increased 1-deoxySL levels observed in HSAN1, an inherited axonal neuropathy. The neurotoxic effect played by 1-deoxySL on cultured primary neurons and the elevated 1-deoxySL plasma levels observed in diabetic patients suggested that these lipids are also involved in the pathology of the diabetic neuropathy (DN). The formation of 1-deoxySL is markedly suppressed by oral L-serine supplementation in HSAN1 patients and a transgenic HSAN1 mouse model. We explored the role of serine supplementation in counteracting diabetic neuropathy in a streptozotocin (STZ)-induced diabetic rat model. We previously observed suppression of deoxySL and improvement of peripheral neuropathy applying a preventive treatment scheme in which rats had immediate access to either a standard or a serine-enriched diet. In the present study we extended our investigation to frankly diabetic rats with established peripheral neuropathy by administering serine 8 weeks after uncontrolled diabetes and lasting another 16 weeks. Rats fed with standard diet were used as controls. STZ rats developed a severe hyperglycaemia (400-700 mg/dl) and a clear neuropathic condition, characterized by impaired nociceptive thresholds and reduced nerve conduction velocity (NCV), associated with significantly increased plasma 1-deoxySL levels. As in the preventive study, serine supplementation did not influence hyperglycemia, body weight and food and water intake, but significantly lowered by 70% the 1-deoxySLs (p < 0.0001) without altering typical sphingolipid levels. After 16 weeks of serine supplementation, diabetic rats showed a significant (p < 0.001) recovery of mechanical threshold of about 50%. Also NCV significantly improved (p < 0.01) in serine treated versus non treated diabetic rats (28.5 ± 2.3 and 33.5 ± 3.4 m/sec, respectively). Furthermore, tibial nerve from serine treated diabetic rats showed a 17% increase of Na+ ,K+ -ATPase activity (p < 0.05) in the diabetic untreated group which showed a 28% reduction with respect to normal controls. In summary, our data support the hypothesis that increased atypical 1-deoxySL formation is involved in the pathology of DN. Reduction of these lipids by serine supplementation according to the therapeutic protocol, confirming early preventive studies, could be a novel therapeutic option to treat DSN.

are found in the 5% of CMT patients, representing one of the main genetic defects associated with CMT (Mandich, 2009). Ten years ago, P0 related neuropathies were divided into early onset demyelinating and late onset axonal neuropathies (Shy et al., 2004). We revised all the novel MPZ mutations published during the last ten years to clarify if the previous classification proved to be valid or not. We found 56 novel MPZ mutations reported and considered 51 of them in which detailed clinical data were provided. In 29 novel MPZ mutations (51%), a late onset axonal phenotype was described, while 20 mutations (39%) were associated to an early onset demyelinating neuropathy and 5 cases (10%) had a more typical CMT1 neuropathy. In about half of the patients affected by an early onset P0 neuropathy, variable motor skill delays were described and in most cases the upper limb MCV was below 10 m/s, thus confirming previous observations. The patients presenting a late onset neuropathy had, in most cases, the first symptoms above the third decade. The disability of those patients was frequently mild (CMT neuropathy score below 10) and the course slowly progressive, however, a novel late onset mutation with a rapid progression was reported (Laura et al., 2007). While in most cases a genotype-phenotype correlation could be established, the mutation L48P may have a very variable onset and disease severity, suggesting that, in some cases, other factors may influence the phenotype. In summary, the previous classification proved to be valid in most cases. The number of late onset MPZ mutations has dramatically increased in the last years and this phenotype seems to account for 30% of the P0 related neuropathies. Since the familiarity for neuropathy is often unclear due to the late disease onset, the number of patients carrying this genotype is still probably underestimated.

EPIDERMAL NERVE FIBER QUANTIFICATION IN IMMUNOFLUORESCENCE WITH AND WITHOUT CONFOCAL MICROSCOPY Provitera V1 , Nolano M1 , Stancanelli A1 , Caporaso G1 , Vitale DF1 , Santoro L2 . 1 “S. Maugeri” Foundation IRCCS, Center of Telese Terme (BN); 2 Department of Neurological Sciences, University of Naples “Federico II”, Naples, Italy. The count of epidermal nerve fibers per linear millimeter, performed on skin biopsies, is an objective and reliable tool to detect small fiber neuropathies. Indirect immunofluorescence is one of the two immunohistochemical techniques used to visualize nerve fibers in the skin, the other one being brightfield microscopy. The count on skin samples processed with indirect immunofluorescence is classically performed by manually tracing ENFs while navigating through the optical sections of 3D confocal images with the aid of the dedicated image analysis software Neurolucida. Alternatively, similarly to the procedure adopted for brightfield microscopy, ENFs can be counted, without confocal, directly through the oculars of a standard epifluorescence microscope. No study has specifically compared counts obtained using Neurolucida and direct observation through the oculars of an epifluorescence microscope so far, therefore we designed this study to verify the agreement between the two count methods.

EARLY AND LATE ONSET P0-RELATED NEUROPATHIES: IS THIS CLASSIFICATION STILL USEFUL? Prada V1 , Callegari I1 , Passalacqua M1 , Capponi S1 , Bellone E1 , Mandich P1 , Shy ME2 , Schenone A1 , Grandis M1 . 1 Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics and Maternal/Child Sciences, University of Genova, Italy; 2 Department of Neurology, University of Iowa Carver College of Medicine, Iowa City, IA, USA. Mutations in the myelin protein zero gene (MPZ), encoding P0, the major structural protein of peripheral nerve myelin

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For this purpose, we evaluated ENF density in the same series of skin samples randomly selected from our library using both computer assisted image analysis and ENF density direct count. The same standard counting rules, as defined by published guidelines, have been adopted to identify fibers eligible for count. The analysis of the measurements showed an excellent agreement between the two methods. Pearson regression showed a significant correlation between paired measures (p < 0.001, r = 0.99). Bland Altman analysis showed a mean difference between the two methods of nerve quantification equal to 0.46 fibers/mm with a SD of ±0.91 fibers/mm. Computer assisted analysis of 3D confocal digital images from samples stained with immunofluorescence techniques, remains the procedure of choice for second level analysis of skin samples, including the quantification of the complex innervation of dermal annexes. However, for the routine measure of epidermal nerve fiber density, the direct observation at epifluorescence microscope has proven as reliable as the more complex and time-consuming computer assisted procedure.

strength was observed. The peculiarity of this case is the incidental detection of NK cell proliferation by cytofluorimetric analysis of CFS in the absence of peripheral leucocytosis. Accordingly with the literature, the worsening of clinical condition after IVIG treatment could be explained by the role of IVIG in tissue redistribution of NK cells and in inhibition of their immunomodulatory function. In our opinion, in cases of suspected GBS, cytofluorimetric analysis of CSF is necessary in order to detect NK cell proliferation, a possible contraindication of treatment with IVIG.

DEFINING THE PERIPHERAL NERVE ENVIRONMENT IN AMYOTROPHIC LATERAL SCLEROSIS AND MOTOR NEUROPATHIES: MORPHOLOGICAL AND WG EXPRESSION STUDIES IN HUMAN MOTOR NERVE BIOPSIES

Richelli S, Buono R, Cavallaro T, Fabrizi G, Tinazzi M, Ferrari S, Vattemi G, Monaco S. Department of Neurological and Movement Sciences, Section of Neurology, University of Verona, Verona, Italy.

Riva N1 , Domi T1 , Clarelli N2 , Dina G1 , Cerri F1 , Podini P1 , Gallia F3 , Nobile-Orazio E3 , Martinelli-Boneschi F2 , Comi G1 , Quattrini A1 . 1 Neuropathology Unit, Department of Neurology and Institute of Experimental Neurology (INSPE), San Raffaele Scientific Institute, Milan, Italy; 2 Laboratory of Complex Genetic Disorders, Department of Neurology and Institute of Experimental Neurology (INSPE), San Raffaele Scientific Institute, Milan, Italy; 3 Department of Neurological Sciences, University of Milan, 2nd Neurology, IRCCS Humanitas Clinical Institute, Rozzano, Milan, Italy.

Lymphoproliferative diseases originating from NK cells include aggressive NK-cell LGL leukaemia and chronic NK-cell lymphocytosis (CNKL). CNKL is characterised by a persistent elevation of NK cells (CD3-CD16/CD56+) in peripheral blood, not associated with lymphoma and with favourable prognosis. The diagnosis of CNKL is based on the following criteria: 1) absolute lymphocytosis for at least 6 months; 2) the demonstration of NK cell phenotype; 3) absence of a clinical diagnosis of lymphoma. Diagnosis requires at least absolute NK cell count of 0.6x109 /L and NK lymphocyte proportion of 40%. Here we report an unusual case of Guillan-Barré syndrome (GBS) associated with NK-cell proliferation. A 65-year-old man was admitted at a secondary hospital after a three-week history of distal painful paresthesia and progressive weakness at lower limbs. Cerebrospinal fluid analysis showed raised protein level without cell content. Nerve conduction studies revealed a demyelinating polyradiculoneuropathy with conduction blocks. Guillain-Barré syndrome was first suspected and treatment with intravenous immunoglobulins (2 g/Kg) was started. Despite the treatment, neurological conditions worsened leading to severe tetraparesis without respiratory involvement. In a second lumbar puncture, the cytofluorimetric analysis disclosed an abnormal amount of NK cells. The same cells were detected also in peripheral blood samples and bone marrow biopsy. Sural nerve biopsy demonstrated signs of axonal neuropathy as well as intraneural infiltrates of mononuclear cells, predominantly NK. Although no specific treatment was introduced, serial analysis of blood samples revealed a progressive reduction of NK cells and a continuous progressive improvement in limb

The causes and pathogenesis of amyotrophic lateral sclerosis (ALS) remain poorly understood. To date, only a few treatments can prolong survival of ALS patients, and an identified biomarker is still lacking for the diagnosis of this disease. Therefore, the characterization of pathways involved in the pathogenesis of this disease could help in the identification of new biomarkers and to provide insight into the development of new therapeutic strategies. As a first step, we demonstrated specific alterations in human ALS motor nerves, supporting the utility of the biopsy of the motor branch of the obturator nerve for an early differential diagnosis of selected cases of lower motor neuron disease. Specific histopathologic diagnostic criteria have been established for proper interpretation of motor nerve biopsies. To investigate the molecular changes underlying ALS, we performed whole genome expression (GE) profiling study on motor and sural nerve biopsies. Based on pathologically-validated diagnosis, the following groups of patients have been studied: Group 1, ALS (N:10); Group 2, Motor Neuropathy (N:8); Group 3, controls (normal sural nerves, N:4); Group 4, hereditary demyelinating neuropathy (CMT1, N:5); Group 5, chronic axonal neuropathy of undetermined origin (CIAP) without signs of inflammation (N:5); Group 6, vasculitic neuropathy (N:10); Group 7, chronic inflammatory demyelinating peripheral polyradiculoneuropathy (CIDP, N:5). Total RNA was isolated from nerves by using the RNeasy kit (Qiagen). RNA was quantified using the Nanodrop-2000 spectrophotometer (Celbio), the Agilent 2100 Bioanalyzer was used to assess the RNA integrity. GE study was performed using the

GUILLAIN-BARRÉ SYNDROME ASSOCIATED WITH CHRONIC NK-CELL PROLIFERATION

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Illumina Beadchips. For each experimental condition, 4 up to 10 biological replicates have been analysed. Sample clustering analysis based on the absolute correlation metric parameter was also generated with the GenomeStudio software. The dendrograms were able to show a good segregation of our group samples. Differentially expressed genes were identified. Subsequently, we carried out a pathway analysis, in order to assign biological meaning to the group of differentially expressed genes. Our preliminary data suggest similar gene expression profiles in the different diagnostic groups and stimulate further analyses in order to unravel the pathogenetic pathways underlying the development of ALS and other PNS disorders.

signal intensity on T2-weighted STIR and faint enhancement; the biggest one measured 3 x 1.7 x 2 cm. No subcutaneous nodular masses were Detectable. A radiological differential diagnosis between inflammatory neuropathy and neurofibromatosis was not easy. However, the hypothesis of a concomitant or alternative diagnosis of neurofibromatosis is unlikely, since no cutaneous or ocular features are present and genetic molecular test (FISH) is negative. Though hypertrophic forms of CIDP are commonly more severe and less frequently paucisymptomatic, accordingly with the recent diagnostic guidelines, the present case can be framed as a prominently motor CIDP. The extent of root and plexus inflammation is surprising compared to the poverty of the clinical picture, likely correlating with a long duration of disease (14 years instead of 5). The mimicking between inflammatory hypertrophic neuropathies and neurofibromatosis, both from the radiological and hystological point of view, is intriguing and will be presented.

A CASE OF HYPERTROPHIC NEUROPATHY: A CLINICAL, NEUROPHYSIOLOGICAL AND RADIOLOGICAL CHALLENGE Romito S1 , Zimatore DS2 , Ferrari S3 , Cavallaro T3 , Zamò A4 , Squintani G1 , Moretto G1 . 1 Neurology Unit, Neuroscience Department, Azienda Ospedaliera Universitaria Integrata, Verona, Italy; 2 Neuroradiology Unit, Azienda Ospedaliera Universitaria Integrata, Verona, Italy; 3 Neuropathology Unit, Neuroscience Department, University of Verona, Azienda Ospedaliera Universitaria Integrata, Verona, Italy; 4 Department of Pathology, University of Verona, Azienda Ospedaliera Universitaria Integrata, Verona, Italy.

SEVERE CUTANEOUS ADVERSE EFFECT IN A PATIENT AFFECTED BY CIDP TREATED WITH HIZENTRA Rosso T, Lelli S, Repice R, Maccarrone G. UO Neurologia, Ospedale di Castelfranco Veneto, ULSS 8 TV, Italy.

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a disabling disorder affecting the peripheral nervous system that needs a precocious treatment to prevent disease progression and axonal degeneration. Immunomodulating treatment with intravenous IgG (IVIG) is effective and well consolidated in the literature, but more recently the subcutaneous route (SCIG-Hizentra) has been proposed since it is relatively free from systemic adverse effects (AE) as compared with IVIG, but local infusion site reactions have been described, including local edema, induration, erythema and local heat, pain or itching. In our hospital, 3 CIDP patients have been shifted from IVIG to SCIG. Two had been on treatment with IVIG for many years and tolerated well the change. The last patient had a more recent diagnosis (an obese female with recurrent moderate asymmetric paraparesis and 4 limbs dysesthesia in the last year) and she had an initial induction with 2 g/kg intravenous IVIG in 5 days, for 5 months. Two weeks after the last course of IVIG, she was shifted to home, self-administered subcutaneous administration (200 gr in 5 days of therapy and 2 rest days, injected below the transverse umbilical line on the inferior part of abdomen). After 46 days of SCIG therapy, she developed a severe, painful and itching cutaneous erythema at the sites of injection rapidly spreading to the entire abdomen. Repeated nurse-monitored injections obtained the same result: the technique was correct but the reaction was still present. The patient had to stop SCIG, she needed 2 other courses of IVIG (2 g in 5 days) after one month, because of clinical worsening. Two weeks after the second treatment with IVIG, she could use SCIG again, rotating the injection side in the upper abdomen with less subcutaneous adipose tissue. The injection schedule was reassessed with a reduced infusion rate and a decreased dose (192 gr in 6 days) and then after a month she returned to the initial setting. We conclude that

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) represents an increasingly wide spectrum of immune-mediated neuropathies. We report the case of a young woman diagnosed with prominent motor CIDP five years ago. On admission to hospital she presented with an acute left third cranial nerve deficit. She reported in anamnesis the same disorder 1 year before, and left leg asthenia and paresthesias episodes from 1999. All previous symptoms had spontaneously resolved. The electrodiagnostic study demonstrated a mild demyelinating proximal neuropathy, with a probable conduction block in the left ulnar nerve, exclusively involving motor fibres. CSF analysis showed increased proteins (1.3 g/L) with no cells. SEPs demonstrated a proximal sensory involvement of all four limbs. The patient was treated with IVIg with benefit. The therapy was periodically repeated in the next years; the clinical picture remained always paucisymptomatic, mainly characterised by fatigability and paresthesias and pain at lower limbs. Last year the patient underwent a biopsy of a laterocervical mass that was diagnosed as probable neurofibroma. Thus she underwent MRI of the spine demonstrating thickened and faint enhancing nerve roots at all levels. In particular, the cauda equina was dramatically enlarged by the nodular thickening of enhancing nerve roots. There was also an enlarged ganglia in a lumbar neural foramen and nodular hypertrophy of an intercostal nerve. Moreover, thoracic MRI showed bilateral large nodular masses throughout the course of all the components of brachial plexus, from the neural foramen to the axilla (roots, trunks, divisions, chords and terminal branches). The nodular masses had high

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SUBACUTE ONSET OF GM1-GM2 IGM-POSITIVE, MULTICRANIAL AND AUTONOMIC NEUROPATHY IN A PATIENT WITH TYPE 2 DIABETES MELLITUS

SCIG is a recommended treatment for CIDP, as effective and safe as IVIG, but better tolerated, since it does not require venous access and can be administered at home. It may give better quality of life to patients and family. We suggest to be very careful to select the injection topography.

Schirinzi E1 , Franciotta D2 , Beronio A1 , Godani M1 , Siciliano G3 , Del Sette M1 , Benedetti L1 . 1 Department of Neurology, Osp. S. Andrea, La Spezia; 2 Laboratory of Neuroimmunology, IRCCS, “C. Mondino” National Neurological Institute, University of Pavia, Pavia; 3 Department of Clinical and Experimental Medicine, Neurological Clinic, University of Pisa, Pisa, Italy.

SCREENING OF THE SH3TC2 GENE IN A COHORT OF EARLY-ONSET CMT4 PATIENTS Saveri P, Piscosquito G, Moroni I, Gandioli C, Milani M, Taroni F, Pareyson D. IRCCS Foundation, C. Besta Neurological Institute, Milan, Italy.

Peripheral neuropathies of several types are common in diabetes mellitus. We describe a patient with type 2 diabetes mellitus (T2DM) who subacutely manifested a GM1-GM2 IgM-positive multicranial, and autonomic neuropathy, which responded to corticosteroids, and recurred after corticosteroid tapering. A 69-year-old man with T2DM presented with a two-month history of progressive numbness and tingling at lower limbs, diplopia, hiccup, dysphagia, nausea, and difficulty to digest resulting in loss of appetite (weight loss of 22 pounds). Neurological examination revealed right VI and bilateral VII cranial nerve deficits, with normal sensory and motor systems at four limbs. Deep tendon reflexes were normal. Brain MRI was normal. Routine laboratory tests, ANA, ENA, immunoelectrophoresis, cryoglobulins, anti-HCV antibodies, anti-ACh-receptor antibodies, anti-GQ1b antibodies, neoplastic and paraneoplastic markers were negative. Serum GM1-GM2 IgM antibodies were positive. Cerebrospinal fluid (CSF) total proteins were slightly elevated, without pleocytosis, and with oligoclonal IgG bands (OCBs) that were equal in serum and CSF (mirror pattern). EMG/ENG showed a moderate motor and sensory axonal-demyelinating polyneuropathy. During the hospitalization, he developed orthostatic hypotension, tachycardia, hyperhidrosis and profuse salivation. Intravenous immunoglobulins were ineffective, but high-dose intravenous methylprednisolone, which was followed by oral prednisolone (50 mg daily), led to a full regression of the symptoms. Two relapses occurred over six months concurrently with corticosteroid tapering. The herein described neuropathy showed very atypical and somewhat difficult to explain features, such as the combined multicranial and autonomic involvement, the subacute onset with a progressive and corticosteroid-dependent course, and the positivity for GM1-GM2 IgM antibodies. The presence of such autoantibodies and the OCB mirror pattern corroborate the hypothesis of an autoimmune pathogenesis of the neuropathy.

CMT4C is an autosomal recessive demyelinating form of CMT associated with SH3TC2 mutations. It is characterized by early onset and moderate severity. Marked and early spine deformities are frequent. Cranial nerve involvement such as facial weakness, hearing loss, tongue atrophy and fasciculation, is also common. We screened the SH3TC2 gene in a series of CMT4 patients, to determine frequency and spectrum of its mutations. Direct sequencing of all 17 coding exons is ongoing and will be completed with the help of NGS technology. Inclusion criteria were: pedigree compatible with autosomal recessive inheritance (AR); predominantly demyelinating pattern on nerve conduction study; onset before age 20. Thirty-four patients (30 index cases) were selected, 9 familial and 25 apparently sporadic cases. To date, five patients were shown to have CMT4C: two sporadic patients were homozygous for p.R954X and p.R1109X, respectively, while a third patient had both mutations in compound heterozygosity; the novel p.Q892X mutation was found in two patients from Albania, each one carrying a second mutation (p.R954X and p.R1109X, respectively). Mean age at onset of the 5 CMT4C patients was 10.4 years (range 1–14 years). None of them had motor development delay, four had scoliosis (severe in three), and three had cranial nerve involvement affecting either the VIIth , VIIIth , XIIth or a combination of them. In adult patients, CMTES mean value was 15.25 (range 10–25). All patients had reduced nerve conduction velocities with variable axonal loss. We confirm that the neuropathy of CMT4C was moderate to severe (as assessed by CMTES). Scoliosis and cranial nerve involvement are very frequent and should direct the clinician to perform SH3TC2 gene analysis. CMT4C seems to be a frequent cause of CMT4. In our series, SH3TC2 mutation frequency is at least 16%. This rate also suggests that CMT4C may be the most common type of AR-CMT, outnumbering GDAP1 mutation frequency (about 5% of AR-CMT; Claramunt et al., J Med Genet, 2005). Therefore, patients with demyelinating neuropathy with non-dominant pattern of inheritance, negative for CMT1A duplication, should be tested for SH3TC2 mutations. In our series, all pathogenic sequence variations were nonsense mutations. A novel mutation was found in heterozygous form in two patients from Albania. Interestingly, all the remaining mutated alleles carried the p.R954X or the p.R1109X mutations, the former reported in numerous families of different ethnic origins and the latter only in families with Gypsy ancestry (Claramunt et al., Clin Genet, 2007).

REPORT OF A NOVEL HSPB1 MUTATION IN A PATIENT WITH CLINICAL AND ELECTROPHYSIOLOGICAL EVIDENCE OF DISTAL HEREDITARY MOTOR NEUROPATHY Schirinzi E1 , Lucchesi C1 , Mostacciuolo ML2 , Boaretto F2 , Benedetti L3 , Caldarazzo Ienco E1 , Bugelli G4 , Del Sette M3 , Siciliano G1 . 1 Department of Clinical and Experimental Medicine, Neurological Clinic, University of Pisa, Pisa, Italy; 2 Department of Biology, University of Padova, Padova, Italy; 3 Department of Neurology, Ospedale S. Andrea, La Spezia, Italy; 4 Orthopaedic Clinic, University of Pisa, Pisa, Italy.

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Distal hereditary motor neuropathies (dHMN) are a genetically heterogeneous group of diseases characterized by distal lower motor neuron weakness, with absent or minor sensory involvement. Mutations in the small heat-shock 27 kDa protein 1 gene (HSPB1) and in the small heat-shock 22 kDa protein 8 gene (HSPB8) were previously reported in both dHMN and Charcot-Marie-Tooth 2 (CMT2) patients; these proteins belong to the superfamily of the small heat-shock proteins, ubiquitous molecular chaperones, involved in different cellular processes, including the dynamics of cytoskeletal proteins in the neurofilament network of peripheral nerves. We describe the case of a 54-year-old man with dHMN phenotype (type II), associated with a novel mutation in HSPB1 gene. The patient family history was apparently negative for neuromuscular disorders and his medical anamnesis was unremarkable until the age of 48 years, when the patient progressively started to develop gait impairment and lower limb muscle cramps, in the absence of sensory impairment. He came to our attention at the age of 54 years; the neurological examination revealed lower limb weakness, mainly affecting foot dorsiflexion, distal muscle hypotrophy and reduced Achilles reflexes bilaterally. Neurophysiology evidenced reduced motor amplitude potentials associated with electromyographic changes, suggesting chronic distal denervation. Laboratory examinations failed to show evidence of rheumatologic, neoplastic, infective, hematological and thyroid disorders. Lumbosacral MRI and cerebrospinal fluid analysis were unremarkable as well as the search for anti GM1, MAG and VGK complex antibodies. Mildly increased levels of CPK were detected, without abnormal blood lactate responses in incremental exercise on cycloergometer test; a muscle biopsy was suggestive of chronic neurogenic pattern. Acid Maltase Deficiency was excluded, as well as Kennedy’s disease and SMN-related spinal muscular atrophy. Based on clinical and electrophysiological evidence, a diagnosis of dHMN with adulthood onset was supposed and a molecular DNA analysis performed. The molecular analysis searching for alterations of heat shock 27 kDa protein 1 (HSPB1), caused by mutations of the HSPB1 gene, mapping on 7q11.23 chromosome constituted by 3 encoding exons, revealed a novel heterozygous deletion in exon 2 (c.373_375delGAG), with aminoacid loss at p.Glu125. No alterations were found in HSPB8 gene. The evidence of this new mutation in HSPB1 expands the genetic spectrum of dHMN phenotype, highlighting the prominent role of the encoded protein in peripheral nerves homeostasis and suggesting that the entire sequence analysis of this gene should be considered in patients with a dHMN/CMT2 phenotype.

the second one. A 44-year-old man was admitted to our hospital because of progressive asymmetrical hand weakness exacerbated by the use of steroids given by his general practitioner. Ten days before admission he had diarrhea and fever. Neurologic examination showed severe asymmetrical weakness of intrinsic hands’ muscles and of wrist extensor muscles (left > right), and normal strength in upper limb muscles; retained tendon reflexes; and normal strength in lower limb muscles. All systemic laboratory tests were normal. Cerebrospinal fluid revealed increased proteins (7.8 g/L). Serological tests revealed Campylobacter jejuni positivity. Antibodies against gangliosides showed positivity of IgM isotypes anti-GM1. Electrophysiological studies have been performed at admission (two days after onset of weakness) and after every week for 1 month. The first exam has shown a motor conduction block without temporal dispersion in the ulnar nerves and in the right medial nerve, and the reduction of cMAP in the left peroneal nerve. F wave was absent in ulnar nerves and in right medial nerve. The motor conduction velocity was normal in all nerves (bilateral SPI, SPE, median and ulnar), but the onset of cMAPs were all increased. The antidromic sensory nerve conduction study was normal. Electromyography showed reduced recruitment in the first interosseus muscle. After one week we observed an amelioration of the amplitudes of proximal and distal cMAP (left ulnar nerve) with reduction of MCV elbow-under elbow of the right ulnar nerve. The EMG showed an amelioration of recruitment in all tested muscles. The evoked potential somatosensory analysis was normal. The asymmetrical weakness, its exacerbation by use of steroids, the presence and persistence of conduction blocks and the presence of serum IgM autoantibodies binding to ganglioside GM1, support the diagnosis of acute motor conduction block neuropathy. This is relevant for therapeutic choice because only high dose intravenous immunoglobulin is effective in this condition.

PLATELET RICH PLASMA (PRP) AS A NEW THERAPEUTIC STRATEGY FOR SEVERE MEDIAN NERVE COMPRESSION IN CARPAL TUNNEL SYNDROME Siciliano G1 , Schirinzi E1 , Lucchesi C1 , Depaulis V1 , Calabrese R1 , Lencioni M2 , Giorgetti M2 . 1 Department of Clinical and Experimental Medicine, Neurological Clinic, University of Pisa, Pisa; 2 Department of Surgery, University of Pisa, Pisa, Italy. The worsening of quality of life due to a progressive limitation of wrist motion and grip, paresthesias and pain, represents a common reason for patients affected by carpal tunnel syndrome (CTS) to seek care and undergo ambulatory surgery; however, a functional and symptomatic improvement is not always noticed after traditional technique of chirurgical decompression of the median nerve for the patients with a severe compression, with impairment of motor and sensory conduction velocities and atrophy of thenar eminence. Platelet-rich plasma (PRP) is a concentrated source of platelets, as compared to whole blood, with a hyper-physiological content of autologous growth factors and cytokines able to promote tissue regeneration.

A CASE OF ACUTE ONSET OF MULTIFOCAL MOTOR NEUROPATHY Sgarzi M, Servalli C, Agazzi E. AO hpg 23, Bergamo, Italy. Acute motor conduction block neuropathy (AMMN) and the Guillain-Barré subtype of acute motor conduction block neuropathy (AMCBN) are characterized by an acute postinfectious motor neuropathy with conduction blocks with clinical relapses in the first case, and recovery within few weeks in

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action potential (cMAP) amplitude, stimulating the radial and ulnar nerve (recording at extensor indicis and abductor digiti minimi muscles, respectively) associated with active denervation at needle examination in the corresponding muscles innervated by those nerves; neurogenic chronic motor unit potentials (MUPs) and poor recruitment were also present at forearm, arm and shoulder muscles; no conduction blocks (CB) (detected with proximal and root electrical stimulations with collision techniques) were found along axillary, musculocutaneous, median, ulnar and radial nerves. Sensory, motor conduction velocity and sensory action potential (SAP) amplitudes were within the normal range. Somatosensory evoked potentials were normal. Magnetic resonance imaging (MRI) disclosed thickening and hyperintensity on T2-weighted STIR sequences of the entire left brachial plexus, compatible with hypertrophic neuropathy. The patient was treated with intravenous immunoglobulin (IVIg) with clinical benefit. We describe a case of chronic pure motor axonal plexopathy responsive to immunomodulatory treatment that might be reasonably considered a clinical variant of multifocal acquired motor axonopathy (MAMA). Clinical and electrophysiological evaluation in our patient showed a dyshomogeneous brachial plexus involvement with prevailing impairment of the ulnar and radial motor nerve fibers. On the other hand, the MRI findings of the involvement of the entire brachial plexus, CSF analysis, normal F waves and the absence of CB (detected with advanced neurographic techniques), together with response to IVIg, were consistent with a diffuse inflammatory process affecting the brachial plexus, even though with remarkable non-homogeneous fiber involvement and a very likely axonal pathophysiology. MAMA and other dysimmune axonopathies, although a diagnostic challenge, should be recognised because they are treatable disorders. MRI in selected cases is fundamental in order to recognise diffuse or focal nerve impairment and should be considered in the diagnostic work-up of dysimmune neuropathy/plexopathy.

We compared the clinical outcome of 17 patients with a diagnosis of severe median nerve compression in CTS. 10 patients (control group: 6 females and 4 males) undergoing conventional surgical decompression alone and 7 (study group: females) received, in addition, application, at direct contact with median nerve, of a diskette soaked with platelet-rich plasma (PRP) obtained from centrifugation of autologous blood. The surgical decompression was performed in outpatient, under local anesthesia and ischemia of the whole limb. A mini-incision allowed access to the transverse carpal ligament that was thoroughly dissected both proximally then distally. A clinical and electrophysiological assessment was performed for all patients at T0 basal time (pre-surgical), at T1 time (30 days after surgery) and at T2 time (2 years after surgery). Presence of a positive Tinel sign, subjective experience of paresthesias, ability to index-thumb opposition, and evidence of thenar atrophy were related to sensory and motor nerve conduction parameters. Student T-Test for unpaired and paired data was applied for statistical analysis. The measure of motor nerve conduction velocity showed no significant differences between the two groups. On the contrary, we observed a significant difference (p < 0.001) in pre-and post-operative values of the motor evoked potential amplitude and sensory conduction velocity in the group treated with the PRP application. In addition, the group treated with PRP showed pain-free postoperative outcome and better functional recovery than the control group 2 years after surgery. This study supports usefulness of growth factor-containing PRP application to entrapped median nerve for functional and nerve recovery in TCS patients with severe compression undergoing conventional surgery.

ACQUIRED CHRONIC MOTOR AXONAL PLEXOPATHY RESPONSIVE TO IVIG: CLINICAL, ELECTROPHYSIOLOGICAL AND MAGNETIC RESONANCE IMAGING CORRELATIONS

CMT2B NEUROPATHY: IMPLICATION OF TWO INTERMEDIATE FILAMENT PROTEINS

Squintani G1 , Donato F1 , Zimatore S2 , Romito S1 , Alessandrini L1 , Moretto G1 , Morini A3 . 1 Neurology Unit, Neuroscience Department, Azienda Ospedaliera Universitaria Integrata, Verona, Italy; 2 Neuroradiology Unit, Azienda Ospedaliera Universitaria Integrata, Verona, Italy; 3 Neurology Unit, Neurophysiology Laboratory, Ospedale Santa Chiara, APSS-Trento, Italy.

Stasi M1 , Margiotta A1 , Cogli L1 , Provitera V2 , Nolano M2 , Bucci C1 . 1 Department of Biological and Environmental Sciences and Technologies (DiSTeBA), Università del Salento, Via Provinciale Lecce Monteroni, Lecce, Italy; 2 Neurology Department, “Salvatore Maugeri” Foundation IRCCS-Medical Center of Telese, Telese Terme (BN), Italy.

We describe a case of a 70-year-old woman with a previous diagnosis of left radial nerve entrapment at the arcade of Frohse, unsuccessfully surgically treated, who came to our attention for a progressive weakness in her left arm that began 6 years before. Her past history revealed rheumatoid arthritis diagnosed 13 years before. Neurological examination showed severe hypotrophic muscles innervated by left ulnar and radial nerves (MRC score 1/5) and reduced strength at the level of forearm flexors, arm and shoulder muscles (MRC score 4/5); no sensory deficits were reported. Search for serum antiganglioside antibody was negative and cerebrospinal fluid (CSF) analysis was normal. Electroneurography revealed very low compound motor

Charcot-Marie-Tooth (CMT) disease is the most common inherited neuromuscular disorder, with a prevalence of 1:2500. It comprises a group of genetically and clinically heterogeneous neuronal disorders. CMT2B is an axonal autosomal dominant form of the neuropathy, characterized by progressive distal weakness and wasting, prominent sensory loss leading to hyperkeratosis and severe foot ulcerations often resulting in toe amputations. This peripheral ulcero-mutilating neuropathy is caused by four missense mutations in the rab7a gene. Rab7 is a ubiquitous small GTPase, involved in the regulation of intracellular membrane

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We induced iPSC from fibroblasts obtained by two healthy subjects and 2 CMT1B patients (D102Tfsx12 and S78L mutations). iPSC clones were multipotent, as they could generate cells of different germ layers either in vitro or in vivo in nude SCID (immunodeficient) mice. Then, iPSC were grown in embryo bodies and differentiated in neural crest stem cells by bFGF, EGF and NOGGIN, as revealed by positivity for p75NTR and HNK1. FACS sorted neural crest stem cells (p75NTR/NHK1 positive) were subsequently plated on fibronectin/laminin-coated coverslips in neurobasal medium supplemented with growth factors, ascorbic acid and cAMP, and differentiated in DRG sensory neurons. These cells showed diffuse positivity for neurofilaments, beta-tubulin type III and calcitonin gene related peptide (CGRP), and formed an extended axonal network. Conversely, neural crest stem cells plated on matrigel-coated coverslips in Mesenpro medium supplemented with bFGF and neuregulin 1-ECD generated Schwann cells. iPSC-derived Schwann cells showed spindle shape and birefringence appearance in phase contrast, and immunohistochemical positivity for S100, GFAP and Sox10. Both iPSC-derived DRG sensory neurons and Schwann cells treated with experimental drugs were viable and did not show differences in differentiation and survival. Our results confirm that iPSC-derived neurons and Schwann cells may be a useful tool to test efficacy or toxicity of experimental therapies on human peripheral nerves in vitro.

trafficking and controlling transport to late endocytic compartments. To understand how mutations in a ubiquitous protein specifically affect peripheral neurons, we have performed a two-hybrid interaction screen using Rab7 as bait and a dorsal root ganglia cDNA library. Putative interacting proteins identified were then biochemically and functionally analyzed in order to determine their relationship with Rab7. We identified two intermediate filament (IF) proteins as new Rab7 interacting proteins: peripherin, primarily expressed in peripheral neurons, and vimentin, the major IF protein of mesenchymal cells, also abundantly expressed in early developing neurons and Schwann cells. These proteins, that present a high percentage of similarity, play a role not only in neurite outgrowth during development, but also in axonal regeneration after injury. The interaction with Rab7 has been confirmed by several other assays. Moreover, we observed that Rab7 silencing or Rab7 overexpression changes the soluble/insoluble peripherin and vimentin rates, indicating that Rab7 is important for their assembly, organization and function. In addition, CMT2B-causing Rab7 mutant proteins bind more strongly to vimentin and peripherin and their expression causes a significant increase in the amount of soluble peripherin and vimentin, influencing also phosphorylation of the head domain. In order to understand the role of these interactions, we studied the interaction between Rab7a and peripherin isoforms or vimentin deletion mutants and we are trying to identify kinases responsible for the different phosphorylation pattern caused by the disease-causing mutants. Our data demonstrate that Rab7 interacts with a coil-coiled domain of these proteins leaving their head domains available to be object of post-translational modifications such as phosphorylation. Peripheral neurons are capable of spontaneous axon regeneration depending on signaling pathways including those controlling neurite outgrowth and membrane traffic. Both vimentin and peripherin seem to be involved in axonal regeneration, suggesting that alterations of the interaction with Rab7 might contribute to the development of CMT2B neuropathy.

CLINICAL/SUBCLINICAL PNS INVOLVEMENT AND RESPONSE TO THERAPY IN POSTINFECTIOUS NEUROLOGICAL SYNDROMES (PINS) Toriello A1 , Pugliese ND2 . 1 U.O.S. Neuromuscular Diseases, 2 U.O.C. Rehabiliation Neurology, University Hospital SS Giovanni di Dio e Ruggi d’Aragona, Salerno, Italy.

The postinfectious neurological syndromes (PINS) are a heterogeneous group of disorders of the nervous system. The biological substrate of the concurrent involvement of the central and peripheral nervous system is given by the similarity of the constituents of the central and peripheral myelin and nodal/paranodal proteins, as shown by some antibody-mediated syndromes (anti-GQ1b, paraneoplastic, anti-neurofascin, anti-neutral glycolipid antibodies). The objective of present study was to describe the spectrum of the PINS in our series and evaluate the utility of an early subclinical recognition of the PNS involvement and the relative response to treatment. We studied all patients with PINS consecutively admitted from 2008 to 2013, evaluating: a) clinical variants (encephalitis E, myelitis M, encephalomyelitis EM, encephalomyeloradiculoneuritis EMRN, myeloradiculoneuritis, MRN), b) cerebrospinal fluid data, c) electroneurographic framework. We evaluated the response to steroid therapy and to intravenous immunoglobulin in those unresponsive to steroids. We studied thirty patients with PINS (42.6 ± 17.1 age; range 17–84), classified into 5 subtypes (E:2; M:4; EM:7; MRN: 14; EMRN:3). Five patients showed an albumin-cytological dissociation. Electroneurographic study, carried out in all patients, showed a PNS involvement in

GENERATION OF SENSORY NEURONS AND SCHWANN CELLS FROM HUMAN-IPS CELLS OF CMT PATIENTS: A SUITABLE TOOL TO TEST NEW DEVELOPING DRUGS Tonlorenzi R1 , Rivellini C1 , Ungaro F2 , Meneghini V3 , Gritti A3 , Broccoli V2 , Previtali SC1 . 1 Inspe, Division of Neuroscience, San Raffaele Scientific Institute, Milano; 2 Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milano; 3 Division of Regenerative Medicine, San Raffaele Scientific Institute, Milano, Italy.

Human induced pluripotent stem cells (iPSC) provide an invaluable resource for regenerative medicine, modeling of human diseases, and to test new developing drugs. Within a collaborative project aimed at identifying new chemical drugs to interfere with peripheral nerve myelination, we decided to generate human dorsal root ganglia (DRG) neurons and Schwann cells to test efficacy and toxicity of promising drugs.

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18/30 patients (60%), demyelinating in 13 patients (72.2% ) and axonal in 5 patients (27.8%). An unfavorable outcome was associated with the involvement of the PNS. Eight patients (26.6%) did not respond to steroid therapy, and among them four patients responded to therapy with intravenous immunoglobulin (50%). One patient died. Thirteen patients had follow-up at six months. Two patients received subsequent diagnosis of multiple sclerosis. Three patients, two with myelitis onset, had relapses. Six patients had electroneurographic follow-up and four of these showed improvement. PINS constitute a spectrum of disorders ranging from typical central forms to mixed with PNS involvement. The latter seems to play a crucial role in the clinical evolution and therapy response. This might suggest the need for an “early” electroneurographic study, aimed at identifying the PNS involvement in all variants of PINS and, when present, the indication of intravenous immunoglobulin as first choice therapy.

cells leads to the accumulation of cytoplasmic vesicles, organelles and vacuoles, which results in hypomyelination, block of degradation and demyelination. Interestingly, as the Fig4-Schwann cell conditional mutant resembles a lysosomal storage disorder with a block of the LE/LY progression, we also exploited this model to address whether the trafficking though the endo-lysosomal axis contributes to active myelination, remyelination and regeneration. Our in vitro and in vivo data suggest that altered late endosomal/lysosomal homeostasis significantly impairs active myelination and nerve regeneration.

RITUXIMAB IN TWO CASES OF CHRONIC INFLAMMATORY DEMYELINATING POLYRADICULONEUROPATHY NOT RESPONSIVE TO OTHER TREATMENTS Velardo D, Bianchi F, Mannina D, Mauri E, Comi G, Fazio R. Department of Neurology, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy.

TRAFFICKING THROUGH THE ENDO-LYSOSOMAL AXIS REGULATES MYELINATION AND REPAIR IN THE PERIPHERAL NERVOUS SYSTEM

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a progressive or relapsing-remitting disease causing weakness and loss of sensitivity, probably due to an autoimmune process. Corticosteroids, immunoglobulin and plasma exchange are first-line therapies, but other immunosuppressive or immuno-modulatory drugs would be expected to be beneficial, particularly in patients that are non-responders to conventional treatment. Four randomised trials showed no significant benefit from azathioprine, methotrexate or interferon beta-1a, even if they were not large enough to detect minor or moderate benefit; furthermore, observational studies of other drugs, including cyclophosphamide, cyclosporine, mycophenolate mofetil, rituximab, and alemtuzumab, peripheral blood stem cell transplantation and interferon alpha, have been performed but are insufficient to determine whether any of these drugs are beneficial. Here we report two cases of young CIDP patients non-responders to first-line treatments or other immunosuppressive agents, whose disease improved after treatment with rituximab. The first patient, a 40-year-old man, had a 3.5-year history of relapsing-remitting CIDP with four limbs weakness, numbness and reduction of superficial and deep sensitivity. The patient was initially treated with five bi-monthly cycles of full dose intravenous immunoglobulin, with a further decrease in his autonomy and a new clinical relapse (INCAT ODSS 6), then with high-dose intravenous methylprednisolone followed by oral steroid tapering, with two other relapses, then with monthly high dose intravenous cyclophosphamide (1000 mg/m2 , eleven cycles in twelve months). After further clinical worsening (INCAT ODSS 9), the patient received the first course of rituximab infusion (two 1000 mg intravenous infusions separated by two weeks) followed by retreatment (rituximab 1000 mg) after 6 months, with full recovery of muscle strength and disappearance of sensitivity disturbances (INCAT ODSS 0). The second patient, a 15-year-old boy, had an infantile onset of CIDP treated

Vaccari I1* , Carbone A1 , Alberizzi V1 , Bianchi F2 , Del Carro U2 , Meisler MH3 , Previtali SC4 , Bolino A1 . 1 Human Inherited Neuropathies Unit, 2 Movement Disorder Unit, 4 Neuromuscular Repair Unit, INSPE-Institute of Experimental Neurology, San Raffaele Scientific Institute, Milano, Italy; 3 Department of Human Genetics, University of Michigan, Ann Arbor MI, USA; *present address: INSERM, Paris, France.

FIG4 is a 5-phosphatase highly conserved in eukaryotic cells from yeast to mammals. Concentrations of PtdIns(3,5)P 2 phospholipid are regulated by FIG4 that interacts with FAB1 and VAC14 in a protein complex. PtdIns(3,5)P 2 is located on the cytosolic surface of membranes of the late endosomal compartment and acts as a molecular signal for trafficking and fusion of intracellular vesicles. Phosphoinositide signaling is particularly important for the integrity of the nervous system. Depending on the type of FIG4 mutation, different types of neurons and Schwann cells can be differently affected, leading to disorders such as amyotrophic lateral sclerosis (ALS), Yunis-Varón syndrome and Charcot-Marie Tooth neuropathy type 4J (CMT4J). To better understand the pathogenesis of these neurological disorders, we tried to clarify the cell autonomous role of FIG4. The Pale Tremor mouse (plt mouse) is a spontaneous mutant with loss of Fig4 characterized by severe neurodegeneration. Mice present severe tremor, abnormal gait and die within 6 weeks. These mutants also present large cytoplasmic vacuoles in neurons and neuronal loss in different areas of the CNS. These features suggested a predominant role for FIG4 in neurons, although a Schwann cell autonomous role of FIG4 could not be excluded. Here we report that Fig4 has a cell autonomous role in Schwann cells and that loss of Fig4 in these cells contributes to CMT4J. In particular, Fig4 specific ablation in Schwann

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with cyclophosphamide and steroids since he was 3 years old, and then with cyclosporine, methotrexate, intravenous immunoglobulin and steroids. The patient was unable to walk and the use of his arms was severely affected (INCAT ODSS 8); he also had many side effects of medications. The first course of rituximab infusion (two 1000 mg intravenous infusions separated by two weeks) was followed by moderate clinical benefit (arms strength improved) and, above all, he could stop steroids that caused pathological bone fractures. The patient is now undergoing clinical follow-up. Further controlled trials are needed to evaluate short- and long-term efficacy of the drug, but rituximab seems to be a promising new therapeutic option in patients with refractory CIDP.

and severe hearing loss. Moreover, preliminary results of S-adenosylmethionine (SAM) supplementation in two Arts syndrome patients showed improvement of their condition, indicating that SAM supplementation in the diet could alleviate some of the symptoms of patients with PRPS1 spectrum diseases by replenishing purine nucleotides.

LIPID AMOUNT IN DEMYELINATING DISEASES: A TOOL TO MONITOR MYELINATION Visigalli D1 , Capodivento G1 , Casazza S1 , Pastore V1 , Garibaldi S2 , Capello E1 , Mancardi GL1 , Uccelli A1 , Schenone A1 , Nobbio L1 . 1 Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal-Infantile Sciences and CEBR, University of Genoa; 2 Cardiology, Department of Internal Medicine, Research Center of Cardiovascular Biology, University of Genoa, Italy.

MUTATIONS IN PRPS1 AS CAUSE OF PERIPHERAL NEUROPATHY AND HEARING LOSS IN CMTX5: THE ITALIAN EXPERIENCE Velardo D1 , Robusto M2 , Del Carro U1 , Asselta R2 , Duga S2 , Soldà G2 , Previtali SC1 . 1 Department of Neurology, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy; 2 Department of Medical Biotechnology and Translational Medicine, University of Milan, Italy.

Remyelination is a major issue for physicians working on myelin disorders but fast, accurate, and reliable methods to quantify the amount of myelin still lacks, both in humans and experimental models. In this context, the identification of a demyelination/remyelination biomarker specific and sensitive enough to monitor disease progression, to test putative pro-remyelinating compounds and thereby select specific treatments is a prime goal in neurodegenerative research. We focused on the lipid component of the myelin sheath due to the higher lipid to protein ratio and unique lipid composition compared to other cell membranes. In particular, we quantified sphingomyelin and cholesterol content in myelinated tissues and DRG cultures by a fluorescence-based assay. This method allowed us to assess the myelin content of different experimental conditions, i.e., rat and mouse tissues, central and peripheral nervous system, genetic and inducible injury, conditions in which the myelin sheath is different both in structure and chemical composition. We found that sphingomyelin and cholesterol are progressively enriched in wild type tissues and cultures in a time-dependent manner and that dys/demyelinated samples, derived from CMT1A rat and EAE mouse models, showed a significant decrease of lipid content compared to the wild type ones. Interestingly, in wild type DRG cultures treated with forskolin, a reversible demyelinating compound, our assay is able to detect remyelination occurring after the drug removal. To validate our sphingomyelin and cholesterol dosage as myelin biomarkers, we developed an ‘ad hoc’ macro to perform a detailed morphological and morphometrical analysis on myelinated tissues. In particular, for each CMT1A and wild type rat we performed the lipid assay on one sciatic nerve, while the contralateral one was processed for neuropathological examination. A positive correlation between total myelinated area and lipid amount was found. Thus, we are confident that our assay is sensitive, specific and reliable enough to be translated to the study of human myelin disorders. As our goal is to use sphingomyelin and cholesterol quantification to monitor myelin status in disease progression and eventually following therapeutic interventions, we plan to test these biomarkers on human biological fluids of neurological patients.

We describe the first two families identified in Italy with mutation in the gene PRPS1 (phosphoribosyl pyrophosphate synthetase 1) coding for PRS-I protein, which is essential in purine metabolism and nucleotide biosynthesis; mutations in PRPS1 can result in a spectrum of syndromic conditions including PRS-I superactivity, X-linked Charcot-Marie-Tooth disease-5 (CMTX5 or Rosenberg-Chutorian syndrome), Arts syndrome, and X-linked nonsyndromic sensori-neural deafness (DFN2). In general, PRPS1 gain-of-function mutations determine a loss of feedback regulation and hence enzyme superactivity, which in turn causes excessive uric acid production and gout. Conversely, loss-of-function mutations are responsible for DFN2, CMTX5, or Arts syndrome. In this case, the severity of the phenotype seems to correlate with the residual functionality of the enzyme, with milder mutations resulting only in sensory-neural deafness, and more severe genetic defects causing also peripheral neuropathy (CMTX5), or peripheral and central nervous system involvement and increased liability to infections (Arts syndrome), suggesting that these disorders belong to the same disease spectrum. The two CMTX5 families we described are characterized by severe sensory-neural deafness in mutated males, who also present sensory-motor axonal neuropathy in one family and axonal motor neuropathy in the other; pes cavus, reduced distal tendon reflexes, cramps and gait disturbances were main clinical features. Females mostly showed subclinical neuropathy, with needle EMG showing diffuse chronic denervation, without hearing impairment. Marked reduction (>60%) of the PRS-I activity was found in the patients’ erythrocytes compared to controls. Our report underlines that mutations in PRPS1 should be investigated in the presence of axonal peripheral neuropathy with X-linked pedigree

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DIABETIC MONONEUROPATHY MULTIPLEX FOLLOWING RAPID GLYCEMIA NORMALIZATION

first with IVIg, then with IV high dosage steroids had no effects. Six months from the second episode, a painful left femoral mononeuropathy and, two months later, a painless left axillary mononeuropathy occurred. Throughout the observation time, insulin therapy was carried on (HbA1C 6.9-7.8) and the patient never experienced symptoms of hypoglycemia. According to clinical status, periodic nerve conduction studies confirmed the poor recovery of MDN and the substantial stability of the concurrent DSP. The chronological relation between the start of insulin therapy and MDN might suggest treatment-induced diabetic neuropathy (TIDN), previously reported as a reversible generalized or proximal painful disorder with acute onset, typically occurring after rapid glycemic control (Gibbons, 2010). The TIDN clinical pattern encompasses length-dependent and non length-dependent small fiber neuropathies. Nerve conduction studies are often normal or DSP-like, and the sural histology may show chronic damage with regenerative activity, in the absence of active degeneration (Llewellyn, 1986). The still debated pathogenesis includes hypothetical of a relative treatment-induced endoneural hypoglycemia/hypoxia (Dabby, 2009; Gemignani, 2009). TIDN in the clinico-neurophysiological pattern of poorly reversible painful MDN and prominent motor involvement, as in our patient, has not been described. Since experimental findings show that nerve damage induced by hypoglycemia affects preferentially large motor nerve fibers (Mohseni, 2001), we suggest repeated episodes of subclinical hypoglycemia as likely pathogenetic mechanism of the current MDN case.

Volpi N, Insana L, Casali S, Franci L, Celli L, Ginanneschi F, Lorenzoni P, Giannini F. Dipartimento di Scienze Mediche, Chirurgiche e Neuroscienze, Università di Siena, Siena, Italy. Focal/multifocal diabetic neuropathy (MDN), prevalently occurring in older people, is rarer than distal symmetrical polyneuropathy (DSP). We describe a sensory-motor painful MDN with asynchronous onset, shortly following insulin introduction, in a patient affected by long-standing type 2 diabetes mellitus without any previous systemic complications, despite poor treatment compliance and glycemic control. A 64-year-old woman, after a discontinuous 12-year-treatment with oral antidiabetics (HbA1C 12.4%), started insulin therapy, resulting in rapid glycemic normalization (HbA1C 7.2%). One month later, she presented with subacute neuropathic pain and left foot drop. Lumbosacral MRI showed no root compressions. EMG detected an axonal severe prominent motor involvement of left peroneal nerve, in the setting of a mild subclinical DSP. Four months later, similar clinical-EMG features appeared in the right peroneal nerve. Extended blood screening, CSF examination and fat amyloid search were negative. Biopsy of right superficial peroneal nerve and peroneus brevis muscle showed large and small axonal loss and degeneration, endoneurial microangiopathy and muscle neurogenic atrophy, without vasculitic changes. Autonomic functions were normal and no systemic involvement was observed. Immunomodulatory treatment,

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