Anti–Leucine-Rich Glioma-Inactivated 1 Autoimmunity Manifest as Faciobrachial Dystonic Seizure

This video from an epilepsy monitoring unit shows the involuntary, synchronous right face, arm, and leg contractions of a man in his 60s who was symptomatic with the episodes over the previous 8 months. There was no clear electroencephalography correlate. Suspicion for faciobrachial dystonic seizure led to serum testing for anti–leucine-rich glioma-inactivated 1 antibodies, which was positive. Anti–leucine-rich glioma-inactivated 1 IgG4 antibodies are thought to be causative of leucine-rich glioma-inactivated 1 encephalitis, which is the second most common cause of autoimmune encephalitis after anti–N-methyl-d-aspartate receptor encephalitis and has an incidence of about 1 case per million.