CASE REPORT/CASE SERIES

Interictal Regional Delta Slowing in Cerebral Sinus Vein Thrombosis Sharon Aharoni, MD,*w Hadassa Goldberg-Stern, MD,*w Liora Kornreich, MD,wz and Avinoam Shuper, MD*w

Abstract: The electroencephalographic finding of regional delta activity should alert to the possibility of an underlying structural abnormality of the brain as a cause. A 5-year-old boy, who presented with severe headache and focal seizures, had normal neurological examination and brain CT findings. The initial electroencephalograph showed focal delta activity. An emergent brain MRI disclosed a thrombosis of the left sigmoid sinus and jugular vein, but no parenchymal lesions. The regional delta activity can presumably serve as a marker for brain tissue damage in cerebral sinus vein thrombosis, and sometimes, even to add information to that gained from imaging studies. Key Words: cerebral sinus vein thrombosis, seizures, neuronal injury, regional delta slowing

(The Neurologist 2015;19:85–88)

R

ibes was apparently the first to describe the clinical presentation of cerebral sinus vein thrombosis (CSVT).1,2 The most common symptoms are headache, vomiting, transient or persistent visual obscuration, focal or generalized seizures, lethargy, and coma. CSVT is rare in children, occurring in around 0.67 per 100,000 children per year.3,4 It can lead to significant, permanent neurological morbidity and even death. The diagnosis of CSVT can be difficult because of the variability of its clinical symptoms and signs. Approximately one third of the patients experience focal or generalized epileptic seizures as the presenting symptom before the diagnosis of CSVT has been established, with some having new-onset seizures within the first 2 weeks of hospital admission.4,5 Surprisingly, possible electroencephalographic (EEG) changes associated with CSVT have received little attention. Described here is the case of a 5-year-old boy with sigmoid sinus thrombosis and interictal regional delta slowing (IRDS). Although magnetic resonance imaging (MRI) of the brain did not disclose parenchymal lesions, it is presumed that the IRDS was a marker of the resultant tissue damage.

CASE REPORT A 5-year-old boy presented with headache of 1 month’s duration. There had been no vomiting or behavioral changes, and he had been treated with analgesics. His parents brought him to the hospital because his headache had worsened, he had vomited twice, and he had become From the Departments of *Neurology; zImaging, Schneider Children’s Medical Center of Israel, Petach Tikva; and wSackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. The authors declare no conflict of interest. Reprints: Avinoam Shuper, MD, Department of Neurology, Schneider Children’s Medical Center of Israel, Petach Tikva 49202, Israel. E-mail: [email protected]. Copyright r 2015 Wolters Kluwer Health, Inc. All rights reserved. ISSN: 1074-7931/15/1903-0085 DOI: 10.1097/NRL.0000000000000009

The Neurologist



Volume 19, Number 3, February 2015

drowsy. He had no past history of migraine, and the family history was unremarkable. On admission, his body temperature was normal and there was no neck stiffness, but he appeared to have photophobia. He was fully oriented, and the findings on neurological examination and eye funduscopy were normal. Shortly after being examined, he had a focal seizure on the right side. A contrast-enhanced brain CT scan revealed no abnormalities, but the EEG showed marked general slowing of delta wave activity over the left hemisphere (Fig. 1). This finding taken together with increased severity of the headaches and the occurrence of a focal seizure prompted the referral to an emergent brain MRI study. MRI with gadolinium showed an absence of a signal void in the left sigmoid sinus and proximal jugular vein, and engorged leptomeningeal veins were visible in the occipital and temporal region (Figs. 2A, B). He was diagnosed as having CSVT. Treatment consisted of low– molecular weight heparin and phenytoin. The workup for background causes of CSVT (see below) was negative, and the patient was discharged pain free and symptom free after 1 week of hospitalization. At the 6-month follow-up visit, the neurological examination revealed no abnormalities, and the repeat MRI study showed nearly complete recanalization of the sigmoid and transverse sinuses. The EEG, although improved, continued to show irregular left occipital slowing for several months (Fig. 3).

DISCUSSION Numerous causes of CSVT have been described in the literature. The risk factors for venous thrombosis in general are linked to the stasis of the blood, changes in the vessel wall, and changes in the composition of the blood. Risk factors are usually divided into acquired risks (eg, surgery, trauma, dehydration, pregnancy, puerperium, antiphospholipid syndrome, cancer, exogenous hormones) and genetic risks (inherited thrombophilia such as protein C and protein S deficiencies).6 CSVT caused by infection is more common in children, mainly in parameningeal locations (ear, sinus, mouth, face, and neck).4,7 In neonates and young infants, dehydration and perinatal events are common. Clinical features are age dependent and more difficult to recognize in infants and young children. Common clinical presentations include headache, lethargy, nausea, and vomiting, and signs of increased intracranial pressure, including papilledema and sixth nerve palsy. Seizures are more common in CSVT than in cerebral arterial thrombosis and in general, CSVT has a better prognosis in terms of survival.8 The favorable outcome is probably attributable to the development of a collateral circulation.9 Factors associated with a grave prognosis are coma, cerebral hemorrhage, and the presence of malignancy.8,10 CSVT may be underdiagnosed. Although the introduction of advanced neuroimaging techniques has improved diagnostic capabilities, imaging studies may fail to reflect the true clinical picture. CT scan remains to be normal in up to 26% of cases with proven CSVT,11 as was the case with our patient. According to the American Heart Association/American www.theneurologist.org |

85

The Neurologist

Aharoni et al



Volume 19, Number 3, February 2015

FIGURE 1. Electroencephalograph. Note the marked slowing over the left occipital and temporal region.

Stroke Association recommendations, although a plain CT or MRI is useful in the initial evaluation of patients with suspected CSVT, a negative plain CT or MRI does not rule out CSVT. A venographic study (either CTV or MRV) should be performed in suspected CSVT if the plain CT or MRI is negative or to define the extent of CSVT if the plain CT or MRI suggests CSVT.6 Contrast-enhanced CTV is highly

sensitive and specific for childhood CSVT diagnosis. In most circumstances, MRI is the diagnostic modality of choice in pediatric CSVT. In children, and increasingly in neonates, the mainstay of CSVT treatment is anticoagulation, including low–molecular weight heparin, intravenous unfractionated heparin, and warfarin.12 Supportive treatment for children with CSVT should

FIGURE 2. MRI of the brain. A, T2-weighted axial view at the level of the posterior fossa. Note the signal in the left sigmoid sinus, indicative of thrombus (arrow). B, T1-weighted axial view after gadolinium injection. Note the engorged veins (arrows) in the occipital and left temporal regions, secondary to the sinus thrombosis.

86 | www.theneurologist.org

Copyright

r

2015 Wolters Kluwer Health, Inc. All rights reserved.

The Neurologist



Volume 19, Number 3, February 2015

Delta Slowing in Sinus Vein Thrombosis

FIGURE 3. Electroencephalograph 1 week later. Marked improvement of IRDA in parallel with clinical improvement of the child’s condition.

include appropriate hydration, control of epileptic seizures, and treatment of elevated intracranial pressure. Headache and a right-sided focal seizure were the main clinical manifestations of our patient’s CSVT. The incidence of seizures in CSVT is 40% to 50% in children, and even higher in neonates.3,4 The seizures are focal in about one half of affected patients. Stam13 considered that the occlusion of the cerebral veins caused both focal neurological deficits and seizures due to localized edema and venous infarction, leading to ischemic neuronal damage. Seizures can sometimes develop into life-threatening status epilepticus, and represent the most frequent long-term complication during follow-up.14 Despite the dominant clinical picture of seizures in CSVT, surprisingly little attention has been paid to associated EEG changes in the English literature. The German literature includes 1 case report by Niedermeyer15 who described a 20year-old patient with probable postabortion cerebral venous thrombosis: the EEG showed left hemispheric delta activity, very similar to that of our patient. That author suggested that cortical venous thrombosis may be associated with very pronounced intrapartum EEG changes and prominent widespread slow activity. Our pediatric patient also had a venous thrombosis and delta activity. Bousser et al2 performed EEGs in 34 of 38 patients with CSVT. Those authors found that the most frequent finding was a diffuse slow activity (51%), even in patients presenting mainly with focal signs. Indeed, the observed slowing of the EEG in 16 of the 34 EEGs (47%) was in the delta range. Kermode et al16 reported a female patient with progressive dural venous sinus thrombosis whose noncontrast cranial CT was normal, but her EEG showed irregular generalized delta activity without epileptiform features. The sequence of events that take place in CSVT, including the EEG changes, was reported by Frerichs et al17 who used an experimental animal model. They found that induction of CSVT in rats led to changes in intracranial Copyright

r

pressure and tissue impedance, suggesting that CSVT was followed by brain edema of a predominantly cytotoxic nature. The animals’ EEG changes were similar to those following global cerebral ischemia, and remained pathologic for up to 6 months after thrombosis induction. Delta activity was still dominant 50 hours after CSVT induction. Those authors speculated that the diffuse delta activity originates in the still viable cortical neurons and that it may reflect functional disturbances beyond the cortical gray matter, namely, in the thalamic nuclei, which are responsible for normal EEG synchronization. Rosetti et al18 described temporary disappearance of sleep spindles in deep cerebral venous thrombosis. They suggested that by means of vasogenic edema, deep CSVT may transiently affect thalamic functions, such as spindle generation, or lead to dissociation of spindle and Kcomplex activity. Interestingly, the symptoms and signs of CSVT (ie, lethargy and irritability) are less specific in newborns and infants, potentially leading to delay in diagnosis. It is possible that EEG configurations in newborns and infants are also different from that of older patients. Soman et al19 reported attenuated background, positive rolandic sharp activity, electrographic seizures, asymmetry and asynchrony of the electrical activity in 4 infants who later developed infantile spasms. Notably, Narayanan and Murthy20 reported CSVT in 14% of 22 patients who had nonconvulsive status epilepticus. IRDS is considered to reflect underlying structural abnormalities of the brain.21,22 Gilmore and Brenner23 found a correlation between focal delta activity and imaging findings in CT scans. The results of their study supported the diagnostic importance of continuous focal delta activity and its frequent association with a gross structural lesion, mainly tumor and stroke. Gloor et al22 suggested that localized delta activity appears in cortex overlying a circumscribed white matter lesion or represents localized thalamic or hypothalamic lesions. Frerichs et al17 studied the events that take place in rats

2015 Wolters Kluwer Health, Inc. All rights reserved.

www.theneurologist.org |

87

The Neurologist

Aharoni et al

in response to CSVT. They found that after an initial phase of depression of EEG activity came a period which was characterized by predominance of delta activity. They suggested that the delta-dominated EEG reflects the postischemic metabolic state of the brain and concluded that venous thrombosis was followed by brain edema of a predominantly cytotoxic nature, leading to long-term changes of brain function. Presumably, the EEG slowing represented a summation of the net influence of active neurons on one hand and of surviving centers on the other, after the neuronal hypoxic-ischemic injury due to the CSVT.17 Zubkov et al24 studied the location and extension of CSVT by the use of venography, and the presence, size, and location of the venous infarction and associated mass effect as seen on CT scan of the head. They summarized the distribution of parenchymal lesions in relationship to the occluded venous sinuses. In the reported child, neither the CT scan nor the MRI study showed any parenchymal damage. The only marker of an underlying brain tissue abnormality which was caused by the CSVT was the IRDS in the EEG. The delta activity in this child was not just a postictal phenomenon. It improved gradually over the next several months after the acute event. It may be concluded that CSVT leads to brain tissue damage, the full extent of which is not always detected by regular imaging studies. This injury can manifest by IRDS. The presented child can serve as a reminder that, in addition to the recommended imaging studies, EEG may also serve as a marker of tissue damage in CSVT. Although not as a first-line study, it seems reasonable to include EEG in the routine diagnostic workup in such cases. REFERENCES 1. Ribes MF. Des recherches faites sur la phlebite. Revue Medicale Francaise et Etrangere et Journal de clinique de l’Hotel-Dieu et de la Charite de Paris. 1825;3:5–41, Cited in Bousser et al(2). 2. Bousser MG, Chiras J, Bories J, et al. Cerebral venous thrombosis—review of 38 cases. Stroke. 1985;16:199–213. 3. de Veber G, Andrew M. The Canadian Pediatric Ischemic Stroke Study Group. The epidemiology and outcome of sinovenous thrombosis in pediatric patients. N Engl J Med. 2001;345: 417–423. 4. Sebire G, Tabarki B, Saunders DE, et al. Cerebral venous sinus thrombosis in children: risk factors, presentation, diagnosis and outcome. Brain. 2005;28:477–489. 5. Ferro JM, Canhao P, Bousser MG, et al. ISCVT Investigators. Early seizures in cerebral vein and dural sinus thrombosis. Risk factors and role of antiepileptics. Stroke. 2008;39:1152–1158. 6. Saposnik G, Barinagarrementeria F, Brown RD Jr, et al. American Heart Association Stroke Council and the Council on Epidemiology and Prevention. Diagnosis and management of cerebral venous thrombosis: a statement for healthcare professionals from the American Heart Association/American Stroke Association. Stroke. 2011;42:1158–1192.

88 | www.theneurologist.org



Volume 19, Number 3, February 2015

7. Wasay M, Dai AI, Ansari M, et al. Cerebral venous sinus thrombosis in children: a multicenter cohort from the United States. J Child Neurol. 2008;23:26–31. 8. Breteau G, Mounier-Vehier F, Godefroy O, et al. Cerebral venous thrombosis: 3-year clinical outcome in 55 consecutive patients. J Neurol. 2003;250:29–35. 9. Chang YJ, Hunag CC, Wai YY. Isolated cortical venous thrombosis—discrepancy between clinical features and neuroradiologic findings. A case report. Angiology. 1995;46:1133–1138. 10. Ferro JM, Lopes MG, Rosas MJ, et al. Cerebral Venous Thrombosis Portuguese Collaborative Study Group. Long-term prognosis of cerebral vein and dural sinus thrombosis: results of the VENOPORT study. Cerebrovasc Dis. 2002;13:272–278. 11. Wasay M, Azeemuddin M. Neuroimaging of cerebral venous thrombosis. J Neuroimaging. 2005;15:118–128. 12. Roach ES, Golomb MR, Adams R, et al. American Heart Association Stroke Council; Council on Cardiovascular Disease in the Young. Management of stroke in infants and children: a scientific statement from a Special Writing Group of the American Heart Association Stroke Council and the Council on Cardiovascular Disease in the Young. Stroke. 2008;39:2644–2691. 13. Stam J. Thrombosis of the cerebral veins and sinuses. N Engl J Med. 2005;352:1791–1798. 14. Ferro JM, Canhao P, Stam J, et al. ISCVT Investigators. Prognosis of cerebral vein and dural sinus thrombosis: results of the International Study on Cerebral Vein and Dural Sinus Thrombosis (SCVT). Stroke. 2004;35:664–670. 15. Niedermeyer E. Intracranial venous thrombosis. In: Niedermeyer E, da Silva FL, eds. Electroencephalography Basic Principles, Clinical Applications and Related Fields. 4th ed. Baltimore: Lippincott Williams & Wilkins; 1987:332–333. 16. Kermode AG, Ives FJ, Taylor B, et al. Progressive dural venous sinus thrombosis treated with local streptokinase infusion. J Neurol Neurosurg Psychol. 1995;58:107–108. 17. Frerichs KU, Deckert M, Kempski O, et al. Cerebral sinus and venous thrombosis in rats induces long-term deficits in brain function and morphology—evidence for a cytotoxic genesis. J Cereb Blood Flow Metab. 1994;14:289–300. 18. Rosetti AO, Maeder-Ingvar M, Reichhart MD, et al. Transitory sleep spindles impairment in deep cerebral venous thrombosis. Neurophysiol Clin. 2005;35:19–23. 19. Soman TB, Moharir M, deVeber G, et al. Infantile spasms as an adverse outcome of neonatal cortical sinovenous thrombosis. J Child Neurol. 2006;21:126–131. 20. Narayanan JT, Murthy JM. Nonconvulsive status epilepticus in a neurological intensive care unit: profile in a developing country. Epilepsia. 2007;48:900–906. 21. Tao JX, Chen XJ, Baldwin M, et al. Interictal regional delta slowing is an EEG marker of epileptic network in temporal lobe epilepsy. Epilepsia. 2011;52:467–476. 22. Gloor P, Ball G, Schaul N. Brain lesions that produce delta waves in the EEG. Neurology. 1977;27:326–333. 23. Gilmore PC, Brenner RP. Correlation of EEG, computerized tomography, and clinical findings. Study of 100 patients with focal delta activity. Arch Neurol. 1981;38:371–372. 24. Zubkov AY, McBane RD, Brown RD, et al. Brain lesions in cerebral venous sinus thrombosis. Stroke. 2009;40:1509–1511.

Copyright

r

2015 Wolters Kluwer Health, Inc. All rights reserved.

Interictal regional delta slowing in cerebral sinus vein thrombosis.

The electroencephalographic finding of regional delta activity should alert to the possibility of an underlying structural abnormality of the brain as...
264KB Sizes 0 Downloads 11 Views