Abstract:

Objective: To summarize the clinical and EEG characteristics of anti-leucine-rich glioma-inactivated 1 (LGI1) antibody-associated encephalitis. Methods and Results: The clinical data and EEG characteristics of 27 patients diagnosed with anti-LGI1 antibody-associated encephalitis in Beijing Tiantan Hospital, Capital Medical University from April 2014 to May 2019 were retrospectively analyzed. 1) Clinical features: the main manifestations were memory loss [70.47% (20/27)] and mental abnormality [51.60% (14/27)]. 2) Laboratory examination: serum anti-LGI1 antibody was positive in all patients, 92.59% (25/27) cerebrospinal fluid anti-LGI1 antibody was positive, some patients were accompanied by hyponatremia [66.67% (18/27)], elevated tumor markers [33.33% (9/27)], and cytomegalovirus IgG was positive [36.36% (8/22)]. 3) Imaging features: head FLAIR showed hyperintensity in 51.85% (14/27) mainly accumulated temporal lobe and hippocampus, and ¹⁸F-FDG PET showed high metabolism in 14/17 mainly accumulated temporal lobe, hippocampus and basal ganglia. 4) EEG characteristics: there were 19 cases (70.37%) of EEG abnormalities, including 10 cases of faciobrachial dystonic seizures (FBDS) alone, 4 cases of focal onset with disturbance of consciousness, 3 cases of FBDS with focal onset and disturbance of consciousness, one case of FBDS with focal onset, one case of focal onset alone. Abnormal waves occurred in 15 cases (55.56%), including focal slow wave activity in 9 cases, diffuse slow wave activity in 3 cases, focal radiating sharp wave activity with slow wave activity in 2 cases, focal fast activity with slow wave activity in one case. Abnormal electrical activity occurred in 8 cases (29.63%) within 10 s after the onset of the movement, including 4 cases in the frontal and anterior mesotemporal region, 2 cases in the parietal, occipital and posterior temporal region, one case in the central region, and one case in a wide range of low voltage. Epileptiform discharge was observed in 8 cases (29.63%), including 6 cases in the frontal and anterior mesotemporal regions, 2 cases in the parietal, occipital and posterior temporal regions. In 9 cases (33.33%), the origin of seizures could be determined, including 5 cases in the anterior mesotemporal region, 2 cases in the central and parietal regions, and 2 cases in the parietal, occipital and posterior temporal regions. Conclusions: The abnormal rate of EEG in anti-LGI1 antibody-associated encephalitis was high, and the background changes were mostly slow background and low amplitude. There were mainly scattered sharp waves and slow waves in the interattack period, which was consistent with the EEG characteristics of marginal lobe encephalitis. Epileptiform discharges were predominate in frontal and temporal lobes during seizures and clinical periods.

Key words: Encephalitis, Autoimmune diseases, Epilepsy, Electroencephalography

摘要：

目的: 总结抗富亮氨酸胶质瘤失活蛋白1（LGI1）抗体相关脑炎脑电图特征。方法与结果: 回顾分析2014年4月至2019年5月首都医科大学附属北京天坛医院诊断与治疗的27例抗LGI1抗体相关脑炎患者的临床及脑电图特征。（1）临床特征：主要表现为记忆力减退[74.07%（20/27）]和精神异常[51.85%（14/27）]。（2）实验室检查：血清抗LGI1抗体阳性率达100%（27/27），脑脊液抗LGI1抗体阳性率为92.59%（25/27），部分患者伴低钠血症[66.67%（18/27）]、肿瘤标志物升高[33.33%（9/27）]、巨细胞病毒IgG阳性[36.36%（8/22）]。（3）影像学特征：头部FLAIR成像高信号占51.85%（14/27），主要累及颞叶和海马；¹⁸F-FDG PET提示高代谢占14/17，主要累及颞叶、海马和基底节区。（4）脑电图特征：脑电图异常19例（70.37%），包括单纯面-臂肌张力障碍发作（FBDS）10例、局灶性发作伴意识障碍4例、FBDS伴局灶性发作和意识障碍3例、FBDS伴局灶性发作1例、单纯局灶性发作1例；发作间期15例（55.56%）可见异常波形，包括局灶性慢波9例、弥漫性慢波3例、局灶散发性尖波伴慢波2例、局灶性快慢复合波1例；发作期8例（29.63%）发作10 s内出现异常电活动，包括额区和前中颞区波幅增高、频率减慢的演变4例，顶区、枕区和后颞区演变2例，中央区演变1例，广泛性低电压1例；8例（29.63%）可见临床下痫样放电，包括额区和前中颞区6例，顶区、枕区和后颞区2例；9例（33.33%）明确发作起源部位，包括前中颞区5例，中央区和顶区2例，顶区、枕区和后颞区2例。结论: 抗LGI1抗体相关脑炎脑电图异常率较高，背景改变多为波幅降低、频率减慢；发作间期以散发性尖波伴慢波为主，符合边缘叶脑炎脑电图特征；发作期及临床下痫样放电呈现以额颞区为主的痫样放电。

关键词: 脑炎, 自身免疫疾病, 癫痫, 脑电描记术