INTERESTING IMAGE
Serial FDG PET/CT in Autoimmune Encephalitis With Faciobrachial Dystonic Seizures Albrecht Kunze, MD,* Robert Drescher, MD, MA,Þ Katharina Kaiser, MD,* Martin Freesmeyer, MD,Þ Otto W. Witte, MD, PhD,*þ and Hubertus Axer, MD*þ Abstract: Autoimmune encephalitis (AE) is increasingly recognized as a nonparaneoplastic disorder with autoantibodies to neuronal proteins. Although MRI is frequently unremarkable, PET imaging might contribute to identification of affected brain regions in distinct AE. We report on serial FDG PET in a 72-year-old man with particular AE subtype, with potassium channel complex antibodies and prodromal stage with dystonic seizures. Serial FDG PET/CT revealed that besides limbic structures, basal ganglia are centrally involved and presumably play a key role in the generation of dystonic seizures. Key Words: autoimmune encephalitis, FDG PET, MRI, epilepsy, autoantibodies (Clin Nucl Med 2014;39: e436Ye438)
Received for publication July 8, 2013; revision accepted December 28, 2013. From the *Hans Berger Department of Neurology, †Department of Nuclear Medicine, and ‡Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany. Authors contributions: Dr A. Kunze contributed to the study concept and design, draft, and article revision. Dr R. Drescher contributed to the acquisition of data, analysis, and interpretation. Dr K. Kaiser contributed to the acquisition of data. Dr M. Freesmeyer contributed to the analysis and interpretation of data and for conceptual advice. Dr O.W. Witte contributed to the critical revision of the article and the intellectual content. Dr H. Axer contributed to the study concept and design, draft, and article revision. Conflicts of interest and sources of funding: none declared. Reprints: Albrecht Kunze, MD, Hans Berger Department of Neurology, Jena University Hospital, Erlanger Allee 101, D-07747 Jena, Germany. E-mail: [email protected]. Copyright * 2014 by Lippincott Williams & Wilkins ISSN: 0363-9762/14/3910Ye436
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REFERENCES 1. Irani SR, Michell AW, Lang B, et al. Faciobrachial dystonic seizures precede LGI1 antibody limbic encephalitis. Ann Neurol. 2011;69:892Y900. 2. Irani SR, Alexander S, Waters P, et al. Antibodies to Kv1 potassium channelYcomplex proteins leucine-rich, glioma inactivated 1 protein and contactin-associated protein-2 in limbic encephalitis, Morvan’s syndrome and acquired neuromyotonia. Brain. 2010;133:2734Y2748. 3. Lai M, Huijbers MG, Lancaster E, et al. Investigation of LGI1 as the antigen in limbic encephalitis previously attributed to potassium channels: a case series. Lancet Neurol. 2010;9:776Y785. 4. Lancaster E, Dalmau J. Neuronal autoantigensVpathogenesis, associated disorders and antibody testing. Nat Rev Neurol. 2012;8:380Y390. 5. Andrade DM, Tai P, Dalmau J, et al. Tonic seizures: a diagnostic clue of antiLGI1 encephalitis? Neurology. 2011;76:1355Y1357. 6. Mizobuchi M, Matsuda K, Inoue Y, et al. Dystonic posturing associated with putaminal hyperperfusion depicted on subtraction SPECT. Epilepsia. 2004;45: 948Y953. 7. Rusu V, Chassoux F, Landre E, et al. Dystonic posturing in seizures of mesial temporal origin: electroclinical and metabolic patterns. Neurology. 2005;65: 1612Y1619. 8. Vincent A, Bien CG, Irani SR, et al. Autoantibodies associated with diseases of the CNS: new developments and future challenges. Lancet Neurol. 2011;10: 759Y772.
Clinical Nuclear Medicine
& Volume 39, Number 10, October 2014
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
Clinical Nuclear Medicine
& Volume 39, Number 10, October 2014
PET/CT in AE With Faciobrachial Dystonic Seizures
FIGURE 1. Cerebral MRI of a 72-year-old patient with autoimmune encephalitis (AE) associated with antibodies to the potassium channel complex (LGI1). MRI (AYC, FLAIR and T2 sequences) did not reveal any abnormality of the temporal lobe and basal ganglia in the acute phase of the disease, whereas the patient was experiencing more than 50 per day highly stereotyped short-lasting attacks with arm posturing and facial grimacing on the left side that were previously termed as faciobrachial-dystonic seizures.1 In addition, he had developed a progressive cognitive impairment during the last 2 weeks before admission. The diagnosis of AE was confirmed by high anti-LGI1 antibody serum titers.2Y4 Recordings of interictal and ictal electroencephalograms were unremarkable, which is consistent with previous reports.1,5
* 2014 Lippincott Williams & Wilkins
www.nuclearmed.com
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
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Clinical Nuclear Medicine
Kunze et al
& Volume 39, Number 10, October 2014
FIGURE 2. Serial 18F-FDG PET/CT of the same patient. In the acute stage (day 0, AYC), PET imaging revealed circumscribed hypermetabolism of the right temporal lobe and both basal ganglia (circles). After the high-dose IV corticosteroid therapy and significant improvement of seizures, which now occurred only 1 to 2 times per day in a strong emotional context, follow-up FDG PET/CT (day 30, DYF) showed normalization of the temporal lobe metabolism and almost normalized basal ganglia metabolism. Although PET scans were obtained, the patient was in interictal conditions. For semiquantitative evaluation, ratios of SUVmax values of mesial temporal lobe/cerebellum (RTL/C) and basal ganglia/cerebellum (RBG/C) were calculated at 2 time points (day 0: RTL/C right 1.74, RTL/C left 0.96, RBG/C right 2.28, RBG/C left 2.13; day 30: RTL/C right 0.86, RTL/C left 0.84, RBG/C right 1.73, RBG/C left 1.63). Thus, serial FDG PET/CT emphasizes an involvement of basal ganglia that presumably play a key role in the generation of dystonic seizures, which is in line with studies analyzing ictal SPECT and dystonic posturing in patients with epilepsy.6,7 In general, FDG PET might contribute to the diagnosis of AE, in particular when antibody testing and other imaging modalities are negative.8
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* 2014 Lippincott Williams & Wilkins
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
Serial FDG PET/CT in Autoimmune Encephalitis With Faciobrachial Dystonic Seizures Albrecht Kunze, MD,* Robert Drescher, MD, MA,Þ Katharina Kaiser, MD,* Martin Freesmeyer, MD,Þ Otto W. Witte, MD, PhD,*þ and Hubertus Axer, MD*þ Abstract: Autoimmune encephalitis (AE) is increasingly recognized as a nonparaneoplastic disorder with autoantibodies to neuronal proteins. Although MRI is frequently unremarkable, PET imaging might contribute to identification of affected brain regions in distinct AE. We report on serial FDG PET in a 72-year-old man with particular AE subtype, with potassium channel complex antibodies and prodromal stage with dystonic seizures. Serial FDG PET/CT revealed that besides limbic structures, basal ganglia are centrally involved and presumably play a key role in the generation of dystonic seizures. Key Words: autoimmune encephalitis, FDG PET, MRI, epilepsy, autoantibodies (Clin Nucl Med 2014;39: e436Ye438)
Received for publication July 8, 2013; revision accepted December 28, 2013. From the *Hans Berger Department of Neurology, †Department of Nuclear Medicine, and ‡Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany. Authors contributions: Dr A. Kunze contributed to the study concept and design, draft, and article revision. Dr R. Drescher contributed to the acquisition of data, analysis, and interpretation. Dr K. Kaiser contributed to the acquisition of data. Dr M. Freesmeyer contributed to the analysis and interpretation of data and for conceptual advice. Dr O.W. Witte contributed to the critical revision of the article and the intellectual content. Dr H. Axer contributed to the study concept and design, draft, and article revision. Conflicts of interest and sources of funding: none declared. Reprints: Albrecht Kunze, MD, Hans Berger Department of Neurology, Jena University Hospital, Erlanger Allee 101, D-07747 Jena, Germany. E-mail: [email protected]. Copyright * 2014 by Lippincott Williams & Wilkins ISSN: 0363-9762/14/3910Ye436
e436
www.nuclearmed.com
REFERENCES 1. Irani SR, Michell AW, Lang B, et al. Faciobrachial dystonic seizures precede LGI1 antibody limbic encephalitis. Ann Neurol. 2011;69:892Y900. 2. Irani SR, Alexander S, Waters P, et al. Antibodies to Kv1 potassium channelYcomplex proteins leucine-rich, glioma inactivated 1 protein and contactin-associated protein-2 in limbic encephalitis, Morvan’s syndrome and acquired neuromyotonia. Brain. 2010;133:2734Y2748. 3. Lai M, Huijbers MG, Lancaster E, et al. Investigation of LGI1 as the antigen in limbic encephalitis previously attributed to potassium channels: a case series. Lancet Neurol. 2010;9:776Y785. 4. Lancaster E, Dalmau J. Neuronal autoantigensVpathogenesis, associated disorders and antibody testing. Nat Rev Neurol. 2012;8:380Y390. 5. Andrade DM, Tai P, Dalmau J, et al. Tonic seizures: a diagnostic clue of antiLGI1 encephalitis? Neurology. 2011;76:1355Y1357. 6. Mizobuchi M, Matsuda K, Inoue Y, et al. Dystonic posturing associated with putaminal hyperperfusion depicted on subtraction SPECT. Epilepsia. 2004;45: 948Y953. 7. Rusu V, Chassoux F, Landre E, et al. Dystonic posturing in seizures of mesial temporal origin: electroclinical and metabolic patterns. Neurology. 2005;65: 1612Y1619. 8. Vincent A, Bien CG, Irani SR, et al. Autoantibodies associated with diseases of the CNS: new developments and future challenges. Lancet Neurol. 2011;10: 759Y772.
Clinical Nuclear Medicine
& Volume 39, Number 10, October 2014
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
Clinical Nuclear Medicine
& Volume 39, Number 10, October 2014
PET/CT in AE With Faciobrachial Dystonic Seizures
FIGURE 1. Cerebral MRI of a 72-year-old patient with autoimmune encephalitis (AE) associated with antibodies to the potassium channel complex (LGI1). MRI (AYC, FLAIR and T2 sequences) did not reveal any abnormality of the temporal lobe and basal ganglia in the acute phase of the disease, whereas the patient was experiencing more than 50 per day highly stereotyped short-lasting attacks with arm posturing and facial grimacing on the left side that were previously termed as faciobrachial-dystonic seizures.1 In addition, he had developed a progressive cognitive impairment during the last 2 weeks before admission. The diagnosis of AE was confirmed by high anti-LGI1 antibody serum titers.2Y4 Recordings of interictal and ictal electroencephalograms were unremarkable, which is consistent with previous reports.1,5
* 2014 Lippincott Williams & Wilkins
www.nuclearmed.com
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
e437
Clinical Nuclear Medicine
Kunze et al
& Volume 39, Number 10, October 2014
FIGURE 2. Serial 18F-FDG PET/CT of the same patient. In the acute stage (day 0, AYC), PET imaging revealed circumscribed hypermetabolism of the right temporal lobe and both basal ganglia (circles). After the high-dose IV corticosteroid therapy and significant improvement of seizures, which now occurred only 1 to 2 times per day in a strong emotional context, follow-up FDG PET/CT (day 30, DYF) showed normalization of the temporal lobe metabolism and almost normalized basal ganglia metabolism. Although PET scans were obtained, the patient was in interictal conditions. For semiquantitative evaluation, ratios of SUVmax values of mesial temporal lobe/cerebellum (RTL/C) and basal ganglia/cerebellum (RBG/C) were calculated at 2 time points (day 0: RTL/C right 1.74, RTL/C left 0.96, RBG/C right 2.28, RBG/C left 2.13; day 30: RTL/C right 0.86, RTL/C left 0.84, RBG/C right 1.73, RBG/C left 1.63). Thus, serial FDG PET/CT emphasizes an involvement of basal ganglia that presumably play a key role in the generation of dystonic seizures, which is in line with studies analyzing ictal SPECT and dystonic posturing in patients with epilepsy.6,7 In general, FDG PET might contribute to the diagnosis of AE, in particular when antibody testing and other imaging modalities are negative.8
e438
www.nuclearmed.com
* 2014 Lippincott Williams & Wilkins
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
