LAUSR

Dear Editor, The diagnosis of autoimmune encephalitis relies on clinical, radiological, and laboratory criteria [1]. Neither the clinical presentation nor the neuroimaging studies are able to effectively discriminate between different antibody-mediated syndromes. Antibody testing—the only way to confirm the diagnosis and to detect the pathogenic antibody—is not readily accessible in many institutions, and result may require several weeks to be obtained [1]. On the contrary, electroencephalography (EEG) is a safe, inexpensive, and often informative diagnostic tool. Historically, EEG has had limited utility in the diagnosis of autoimmune encephalitis because only nonspecific EEG patterns were described. Only recently, it was demonstrated that certain EEG findings might have a guiding role in request for antibody testing, as the case of the extreme delta brush pattern in anti-NMDA receptor (NMDAR) encephalitis [1]. It is now generally accepted that Bfaciobrachial dystonic seizures^ (FBDS)—thought to be pathognomonic for leucine-rich glioma inactivated-1 (LGI-1)-antibody encephalitis—lack EEG correlates [2] and in the recent past their epileptic nature was also questioned [3]. Few reports exist on EEG abnormalities recorded prior to FBDS [3]. Here, we describe the importance of ictal EEG findings in a case of anti-LGI1 encephalitis with special emphasis on a recently discovered EEG marker, represented by a frontocentral slow wave that consistently precedes the tonicdystonic movements.