Clinical and electroencephalographic characteristics of symptomatic episodes in anti⁃leucine rich glioma inactivated 1 antibody⁃associated autoimmune encephalitis

Abstract

Objective To summarize the clinical manifestations, EEG and imaging features of patients with symptomatic episodes of anti⁃leucine rich glioma inactivated 1 (LGI1) antibody⁃associated encephalitis (hereinafter referred to as anti⁃LGI1 antibody⁃associated encephalitis). Methods and Results The clinical data of 41 patients diagnosed with anti⁃LGI1 antibody⁃associated encephalitis with symptomatic episodes from March 2019 to March 2022 in Beijing Tiantan Hospital, Capital Medical University were retrospectively analyzed. 1) Clinical features: onset of symptomatic seizures in the early stage of encephalitis in the form of epileptic seizure [34.15% (14/41)], faciobrachial dystonic seizures [FBDS, 17.07% (7/41)] or both [48.78% (20/41)]. 2) Imaging features: the vast majority of patients present with typical unilateral or bilateral medial temporal lobe structures including amygdala and hippocampus, parahippocampal gyrus T₂WI and FLAIR hypersignal [87.80% (36/41)], and/or amygdala swelling [65.85% (27/41)]. 3) EEG characteristics: in the interattack period, slow EEG background was observed [53.66% (22/41)], including diffuse and widespread slow⁃wave activity background [50% (11/22)]. The epileptoid discharges were unilateral (n=8) or bilateral (n=6), or bilateral multifocal, and some patients could still have periodic epileptoid discharges [12.20% (5/41)]. VEEG recordings showed symptomatic seizures [78.05% (32/41)] and FBDS of 59.38% (19/32), of which 3 cases presented faciobrachial dystonic seizures superposition (FBDS+). Epileptic seizure and subclinical seizures were 46.88% (15/32) and 12.50% (4/32), respectively. 4) Drug therapy: all patients received immunotherapy in addition to antiepileptic seizure medicine (ASM), including glucocorticoid combined with intravenous immunoglobulin [IVIg, 78.05% (32/41)], glucocorticoid alone [12.20% (5/41)] or IVIg therapy [9.75% (4/41)]. A small number of patients were supplemented with the immunosuppressive agent mortemycophenolate [14.63% (6/41)]. 5) Prognosis: a total of 37 patients were followed up for (21.36±11.53) months. The total seizure⁃free rate was 86.49% (32/37), and 56.76% (21/37) of patients stopped using ASM. Conclusions Symptomatic episodes of encephalitis associated with anti⁃LGI1 antibody were characterized by temporal lobe or perilateral fissure. FBDS is the most characteristic clinical manifestation. All patients should start immunotherapy as early as possible to improve the rate of good prognosis.

doi：10.3969/j.issn.1672⁃6731.2023.03.010