Characteristics of electroencephalogram in patients with anti-N-methyl-D-aspartate receptor encephalitis / 中华神经科杂志

ABSTRACT

Objective To investigate the characteristics of electroencephalogram (EEG) in patients with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis. Methods In this retrospective study, patients with anti-NMDAR encephalitis who admitted to Xuanwu Hospital of Capital Medical University from January 2012 to June 2015 were enrolled. All patients accepted EEG monitoring at least once, and tumor screening, symptomatic therapy, as well as immunotherapy. Outcomes were assessed by modified Rankin Scale (mRS) 6 and 12 months after immunotherapy, and mRS score 0-2 was defined as favorable outcome. Results Forty-one patients aged (27±12) (13-58) years were enrolled, 19 of whom were male. All patients received EEG monitoring 55 times totally. Among 41 patients in disease peak period, 39 patients (95.1%) had abnormal EEG, 2 patients had normal EEG. The abnormality of brain MRI scan accounted for 51.2%. Abnormal EEG included diffuse slowing (12 patients, 29.3%), epileptic discharges (9 patients, 22.0%), rhythmic delta activity (6 patients, 14.6%), extreme delta brush (EDB) (6 patients, 14.6%), focal slowing (4 patients, 9.8%), and rhythmic delta frequency activity without EDB (2 patients, 4.9%). Clinical items did not show statistically significant difference between the patients with EDB and those without EDB. The patients with normal EEG, epileptic discharges, rhythmic delta activity, or rhythmic delta frequency activity without EDB all had favorable outcomes after 12 months′ treatments. Conclusions The great majority of patients with anti-NMDAR encephalitis had abnormal EEG. EEG could sensitively reflect the changes of brain function and could be helpful in early diagnosis and treatment of this disease. The most common electrographic pattern was found to be diffuse slowing in patients with anti-NMDAR encephalitis. EEG of some patients showed EDB.