Movement Disorders Associated with GABA A Receptor Encephalitis: A Video Case Report Veria Vacchiano MD, 1, * Maria Pia Giannoccaro MD, PhD, 1,2 Rita Rinaldi MD, 3 Maria Guarino MD, 3 and Rocco Liguori MD 1,2 Antibody-associated neurological disorders are a heterogeneous group of inflammatory diseases frequently associated with move- ment disorders (MDs), which can occur in isolation or combined with other signs. Specific clinical patterns and demographic features have been more frequently associated with specific antibodies, for example, neuropsychiatric symptoms and MDs in young females with N-methyl-d-aspartate receptor (NMDAR) encephalitis, peripheral nerve hyperexcitability in elderly men with Contactin- associated protein-like 2 (CASPR2) antibodies, and psychiatric dis- orders in middle-aged women with α-amino-3-hydroxy-5- methyl-4-isoxazolepropionic receptor (AMPAR) antibodies among others. 1 Moreover, some immune-mediated disorders can present with specific and well-defined MDs (ie, faciobrachial dystonic sei- zures), which help to guide the diagnostic work-up and to achieve the diagnosis. 1 However, there are also less characterized and atypical MDs associated with antibody-related diseases, with a considerable overlap between clinical phenotypes and associated antibodies. We report a case of gamma-aminobutyric acid A (GABA A) receptor (GABA A R) encephalitis presenting with isolated atypical movement disorders as first clinical symptom. Case Report A 47-year-old woman with a past history of systemic sarcoidosis came to our attention as a result of the sudden onset of repetitive abnormal movements in the right hand, spread after 1 day to the left hand, and then in the right lip. The neurological examination revealed quasi-rhythmic and stereotyped abnormal movements present at rest (Video S1, seg- ment 1) in the right and left hands, not always synchronous. The same movements were also present during posture, associated with more brief twitches in the inferior and superior right lip (Video S1, segment 2). Distraction maneuver, consisting of a mental task (recognizing which number was drawn on the forehead), did not modify the movements (Video S1, segment 3). The MDs completely resolved after steroid treatment (1 gram/day over 5 days), administered in the suspicion of an autoimmune disorder. However, after steroid dose reduction, the clinical picture became more complex (Fig. 1), with the onset of encephalopathy and refractory status epilepticus. Cere- brospinal fluid analysis revealed a mild pleocytosis and slightly elevated protein; the diagnostic work-up for infectious diseases was negative. Brain magnetic resonance imaging showed mul- tiple cortical-subcortical T2/fluid-attenuated inversion recov- ery hyperintensities in all cerebral lobes, with increased diffusion-weighted imaging signal, without reduced apparent diffusion coefficient values or contrast enhancement (Fig. 1). Antibody testing, using live human embryonic kidney cells expressing α1β2γ2 subunits of the GABA A R revealed high- titer (1,3200) serum GABA A R antibodies, confirming the diag- nosis of autoimmune encephalitis. 2 Cerebrospinal fluid was not available for testing. Other antibodies (VGKC, voltage gated potassium channel; CASPR2, LGI1, leucine-rich glioma- inactivated 1; NMDAR, AMPAR, GAD65, glutamate decar- boxylase 65; GABA B R, gamma-aminobutyric acid receptor) were negative. After rituximab therapy (375 mg/m 2 /weeks for 4 weeks), the patient gradually returned to her premorbid state. She remained asymptomatic at the 2-year follow-up. Discussion The MDs in our patient could be considered atypical because of their mixed clinical features. In particular, they were too slow to be classified as “myoclonic jerks,” which are typically short and 1 Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy; 2 IRCSS Institute of Neurological Sciences of Bologna, UOC Clinica Neurologica, Bologna, Italy; 3 Neurology Unit, S. Orsola-Malpighi University Hospital , Bologna, Italy *Correspondence to: Dr. Veria Vacchiano, Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Via Altura 3,40139, Bolo- gna, Italy; E-mail: veriavacchiano@gmail.com Keywords: GABA A R antibodies, movement disorders, autoimmune encephalitis. Relevant disclosures and conflicts of interest are listed at the end of this article. Received 11 March 2020; revised 9 May 2020; accepted 13 May 2020. Published online 12 June 2020 in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/mdc3.12987 MOVEMENT DISORDERS CLINICAL PRACTICE 2020; 7(6): 681–683. doi: 10.1002/mdc3.12987 681 © 2020 International Parkinson and Movement Disorder Society CASE REPORT CLINICAL PRACTICE