OBSERVATION ONLINE FIRST Kinesigenic Dyskinesia in a Case of Voltage-Gated Potassium Channel– Complex Protein Antibody Encephalitis Enrique Aradillas, MD; Robert J. Schwartzman, MD Objective: To describe the first case (to our knowledge) Results: Clinical examination revealed paroxysmal kine- of voltage-gated potassium channel–complex protein sigenic dyskinesia and fasciculations. Magnetic resonance antibody encephalitis with kinesigenic dyskinesia and imaging of the brain revealed a left caudate and left puta- cramp-fasciculation syndrome. men increased signal lesion on T2-weighted and fluid- attenuated inversion recovery sequences as well as in- Design: Case report. creased flow in the same region on single-photon emission computed tomographic scans. Electromyography and nerve conduction studies revealed significant afterdischarges, Setting: Hospitalized care. cramp potentials, and continuous motor activity. The video- electroencephalographic monitoring revealed no epilepti- Patient: A 38-year-old man with a history of bronchial form discharges. The patient dramatically improved after asthma, eczema, vitiligo, and immune complex mesan- 5 plasmapheresis exchange treatments and a course of in- giopathic glomerulonephritis presented with abnormal travenous immunoglobulin at 2 gm/kg over 5 divided doses. movements. Conclusion: To our knowledge, this is the first report of Main Outcome Measures: Clinical examination, mag- paroxysmal kinesigenic dyskinesia with voltage-gated po- netic resonance imaging, single-photon emission com- tassium channel–complex protein antibody encephalitis puted tomography, electromyography and nerve conduc- associated with the cramp fasciculation syndrome. tion studies, video-electroencephalographic monitoring, plasmapheresis exchange therapy, and intravenous im- Arch Neurol. 2011;68(4):529-532. Published online munoglobulin administration. December 13, 2010. doi:10.1001/archneurol.2010.317 O OUR KNOWLEDGE, THIS IS tiated by change of position or startle and the first description of a pa- would involve either the upper or the lower tient who had central neu- extremities. The movements occurred up rologic signs of seizures, to 40 to 50 times per day and were exac- encephalopathy, and kine- erbated by stress and lack of sleep. The pa- Tsigenic dystonia as well as fasciculations tient subsequently developed clear cogni- and peripheral cramps. tive decline manifested as difficulty with short-term memory and concentration. The Video available online at episodes of anxiety increased in frequency and intensity and were followed by 2 wit- www.archneurol.com nessed generalized tonic-clonic seizures. The patient was admitted to an outlying hos- REPORT OF A CASE pital and underwent an extensive workup, which included routine magnetic reso- A 38-year-old man presented with the chief nance imaging without gadolinium, cere- complaint of the sudden onset of “stiff- bral arteriography, and routine blood, urine, ness” of both arms and legs. The problem and cerebrospinal fluid analysis, the re- had begun 8 weeks earlier, when the pa- sults of which were normal. He also had tient experienced 2 episodes of extreme bronchial asthma, eczema, vitiligo, and Author Affiliations: anxiety that lasted for approximately 30 sec- immune complex mesangiopathic glo- Department of Neurology, onds with no associated loss of conscious- merulonephritis. He was taking 500 mg of Drexel University College of ness or abnormal movements. A few days mycophenolate mofetil (CellCept [2-mor- Medicine, Philadelphia, after these 2 episodes, he noted the onset pholino-ethyl ester of mycophenolic acid]) Pennsylvania. of abnormal movements, which were ini- twice a day for his renal condition. (REPRINTED) ARCH NEUROL / VOL 68 (NO. 4), APR 2011 WWW.ARCHNEUROL.COM 529 ©2011 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/25/2021 A B C D FLAIR FLAIR T1 with gad T2 Figure 1. Magnetic resonance images of the brain. Fluid-attenuated inverse recovery (FLAIR) sequence (A, axial; B, coronal), gadolinium (gad)-enhanced T1-weighted images (C), and T2-weighted images (D), all demonstrating increased signal intensity in the left caudate and putamen (arrows). were stereotyped and lasted 3 to 10 seconds (video, http: //www.archneurol.com). He had full recollection of the events and had no loss of consciousness or confusion. He had 20 to 30 episodes per hour. He also demonstrated fas- ciculations at rest, most prominently of the quadriceps and gastrocnemius muscles. Magnetic resonance imaging of the brain with gado- linium revealed increased fluid-attenuated inverse re- covery signal of the head of the left caudate and the middle of the left putamen (Figure 1). The lesions enhanced with gadolinium (Figure 1C). Single-photon emission computed tomography demonstrated increased uptake in similar regions (Figure 2). Autoantibody and para- neoplastic evaluation revealed an elevated voltage-gated potassium channel (VGKC) antibody titer (0.97 nmol/L; reference value, Ͻ0.02 nmol/L) and an elevated gangli- onic acetylcholine receptor antibody titer (0.45 nmol/L; reference value, 0.02 nmol/L). Electromyography and Figure 2. Single-photon emission computed tomographic scans of the brain nerve conduction studies using the cramp-fasciculation demonstrating increased flow in the left striatum region (arrows). protocol revealed significant afterdischarges with 3-Hz stimulation, significant cramp potentials with 5-Hz stimu- On admission, he was fully alert and oriented but had lation, and continuous motor activity with 10-Hz stimu- trouble with immediate recall and tasks that required con- lation (Figure 3). The serum sodium level on admis- centration (eg, serial 7s). He had slight forward flexed pos- sion was 128 mEq/L (to convert to millimoles per liter, ture but otherwise had full strength, sensation, and coor- multiply by 1.0). A 72-hour continuous video-electro- dination. He demonstrated multiple episodes of kinesigenic encephalographic monitoring system revealed nonspe- dyskinesia, which were always initiated by sudden move- cific slowing but no epileptiform activity. The results of ment (most often by reaching for objects or attempting to a complete malignancy workup, including total-body posi- get up from a sitting position). The movements were at tron emission tomography, were negative. times bilateral and at times unilateral. He would flex at the Levetiracetam therapy (1000 mg twice a day) was ini- elbow and wrist and extend his knees while dorsiflexing tiated and was continued throughout the course of the his foot. His face involved the orbicularis oculi, buccina- patient’s evaluation. The patient underwent 5 plasma ex- tor muscles, and lower facial musculature. The episodes changes during the first week. There was no clinical im- (REPRINTED) ARCH NEUROL / VOL 68 (NO. 4), APR 2011 WWW.ARCHNEUROL.COM 530 ©2011 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/25/2021 200 uV Recording No.: 1 s 200 uV Recording No.: 1 s 12345678910 12345678910 Amp 1: 2-10kHz Amp 1: 2-10kHz 200 uV 2 ms 200 uV 2 ms Stim Freq: 5 Hz No. in Train 900 Stim Freq: 10 Hz No. in Train 900 Stim Dur. 0.1 ms Stim Rjct 0.5 ms Stim Dur. 0.1 ms Stim Rjct 0.5 ms Stim Site: Ankle Stim Site: Ankle Time: 11:54:36 Time: 11:55:35 Comment: Comment: Pot. Peak Amp Area Area Stim Pot. Peak Amp Area Area Stim No. Amp Decr Decr Level No. Amp Decr Decr Level mV % mVms % mV % mVms % 1 1.06 0 6.07 0 46.2mA 1 1.05 0 6.19 0 46.2mA 2 1.06 0 6.04 0 46.2mA 2 0.97 8 6.17 0 46.2mA 3 1.16 – 9 6.09 0 46.2mA 3 0.96 9 6.12 1 46.2mA 4 1.13 – 7 6.04 0 46.2mA 4 0.99 6 5.87 5 46.2mA 5 1.19 – 12 6.09 0 46.2mA 5 1.06 – 1 5.59 10 46.2mA 6 1.15 – 8 6.12 – 1 46.2mA 6 0.98 7 5.57 10 46.2mA 7 1.10 – 4 3.78 38 Limit 7 1.37 – 30 5.70 8 46.2mA Included Stim: 5 Hz, 0.1 ms, #101 8 0.17 84 0.58 90 Limit Included Stim: 10 Hz, 0.1 ms, #188 8 0.80 24 5.48 11 46.2mA 9 0.11 90 0.42 93 Limit 9 1.37 – 30 5.65 9 46.2mA 10 0.07 93 0.11 98 Limit 10 1.11 – 6 5.53 11 46.2mA Figure 3. Electromyography and nerve conduction studies demonstrating cramp potentials (left) and continuous motor unit activity (right) during tibial repetitive nerve stimulation at 5 Hz and 10 Hz, respectively. provement. The second week, 5 intravenous immuno- kinesia and asymptomatic cramp-fasciculation syn- globulin infusions of 2 mg/kg were administered over 4 drome. Also, he did not complain of any of the typical to 5 hours with 30 mg of prednisone. On the 10th day symptoms of peripheral nerve hyperexcitability that have (third intravenous immunoglobulin infusion), the kine- been described in association with VGKC antibody spec- sigenic dyskinesia decreased dramatically to only 1 to 2 trum diseases (neuromyotonia or Isaacs syndrome, cramp- very mild episodes per day. The patient no longer had fasciculation syndrome, and Morvan syndrome).5-9 He did, spontaneous fasciculations. Topiramate (100 mg every however, have prominent fasciculations, especially in the night) was added to his regimen the last week of treat- lower extremities. ment. At the 8-week follow-up visit, his VGKC anti- Until recently, VGKCs were thought to be the anti- body level was undetectable. genic target in these patients.8,9 The work by Lai et al10 and Irani et al11 has demonstrated that the antigenic targets are COMMENT proteins that form a complex with these VGKCs, ie, leucine- rich glioma-inactivated 1 and contactin-associated pro- To our knowledge, this is the first reported case involv- tein 2. Leucine-rich glioma-inactivated 1 associates with ing both VGKC complex protein antibody encephalitis the VGKC KV1.1, and, clinically, patients who had this and fasciculations associated with kinesigenic dyskine- antibody had more central nervous system manifesta- sia.