Abstract:

Objective  To summarize clinical seizures and electroencephalography (EEG) characteristics of patients with anti ? leucine ? rich glioma ? inactivated 1 (LGI1) antibody ? associated encephalitis.  Methods  Clinical manifestations, imaging and EEG characteristics, treatment and prognosis of 35 patients with anti?LGI1 antibody?associated encephalitis, who were clearly diagnosed by laboratory examinations and followed up for 2 years, were analyzed.  Results  Thirty?five patients included 26 males and 9 females, median age 57.35 years. Of all 35 cases, 31 cases (88.57%) had epileptic seizures, mainly as complex partial seizure (CPS), and 13 cases (37.14%) had faciobrachial dystonic seizures (FBDS). Brain MRI showed T2WI and FLAIR high?intensity signals in bilateral (16 cases) or unilateral (12 cases) mesial temporal lobes. 18F ? fluoro ? 2 ? deoxy ? D ? glucose (18F ? FDG) PET examination showed hypermetabolism in temporal lobe and/or basal ganglia (22/24). Thirty?one patients performed video EEG (VEEG) examination, among whom 23 patients showed abnormal background activity, manifesting as diffuse slow waves or regional slow waves in frontotemporal region; 18 cases showed anterior temporal epileptic discharges. There were 22 cases grasping seizures in VEEG, among whom 18 cases obtained epileptic seizures and 13 of them were temporal lobe onset CPS (10 cases) or simple partial seizure (SPS, 7 cases) including pilo?erection seizure in 5 cases, myoclonic seizure in 4 cases and secondary generalized tonic?clonic seizure (GTCS) in one case. Two of 6 FBDS patients showed epileptic discharges followed by temporal lobe onset. Twenty?seven cases received oral antiepileptic drugs (AEDs), among whom 4 of 25 patients with epileptic seizures had reduced frequency ≥ 50%, while 11 FBDS patients had no effect, 8 cases (29.63%) had anaphylaxis. Thirty?five patients received immunomodulation treatment, including intravenous immunoglobulin (IVIg) in 33 cases, corticosteroids in 33 cases, mycophenolate in 4 cases and zathioprine in 2 cases, the seizure frequency of all patients reduced ≥ 50% after treatment. After hospital discharge, 17 patients stop taking AEDs within one year and 26 patients stop taking AEDs within 2 years. Of the patients who were followed up for 2 years, 29 cases achieved epileptic seizure free, only 2 patients developed to chronic epilepsy (anti?LGI1 antibody were negative while seizures were not free).  Conclusions  Anti?LGI1 antibody?associated encephalitis is a kind of autoimmune limbic encephalitis with specific clinical characteristics, often presenting with FBDS and temporal lobe seizures (typically with pilo?erection aura) combined with amnesia, psychiatric disorder/abnormal behavior and hyponatremia. Early diagnosis and timely immunotherapy can achieve good prognosis.

Key words: Limbic encephalitis, Tumor suppressor proteins, Epilepsy, Immunotherapy, Electroencephalography

摘要：

目的 总结抗富亮氨酸胶质瘤失活基因1（LGI1）抗体相关脑炎的癫发作和脑电图特征。 方法 回顾分析35 例经实验室检查明确诊断且随访满2 年的抗LGI1 抗体相关脑炎患者的临床表现、影像学和脑电图特点、治疗及预后。 结果 35 例抗LGI1 抗体相关脑炎患者中31 例（88.57%）表现为癫发作，主要呈现复杂部分性发作；13 例（37.14%）表现为面?臂肌张力障碍发作。影像学主要表现为双侧（16 例）或单侧（12 例）内侧颞叶T2WI 和FLAIR 成像高信号；18F?脱氧葡萄糖（8F?FDG）PET 主要呈现颞叶和（或）基底节区高代谢（22/24 例）。31 例行视频脑电图监测，23 例背景活动异常，呈现弥漫性慢波或以额颞区为主的局灶性慢波；18 例表现为以颞前区为主的样放电；22 例视频脑电图捕获到发作，其中18 例记录到癫发作，13 例表现有颞叶起源的复杂部分性发作（10 例）或单纯部分性发作（7 例），7 例单纯部分性发作患者中5 例为竖毛发作，4 例为肌阵挛发作，1 例继发全面性强直?阵挛发作；6 例面?臂肌张力障碍发作患者中2 例可见继发颞叶起源的样放电。27 例患者予抗癫药物治疗，25 例癫发作患者中4 例发作频率减少≥ 50%，11 例面?臂肌张力障碍发作患者均无效；8 例（29.63%）出现过敏反应。35 例患者均行免疫调节治疗，33 例静脉注射免疫球蛋白、33 例予激素、4 例予吗替麦考酚酯、2 例予硫唑嘌呤，发作频率均减少≥ 50%。逐渐停用抗癫药物，17 例随访1 年内停药，26 例随访2 年时停药。随访2 年，29 例未再出现癫发作，仅2 例进展为慢性癫。 结论 抗LGI1 抗体相关脑炎是具有一定临床特征的自身免疫性边缘性脑炎，典型表现为面?臂肌张力障碍发作和起源于颞叶的癫发作（以竖毛发作为最常见先兆），伴记忆力下降、精神行为异常和低钠血症等。早期诊断、及时予免疫调节治疗，预后良好。

关键词: 边缘叶脑炎, 肿瘤抑制蛋白质类, 癫痫, 免疫疗法, 脑电描记术