[Clinical and electroencephalographic analysis of anti-N-methyl-D-aspartate receptor encephalitis in children]

To study the clinical and electroencephalographic (EEG) characteristics of anti-N-methyl-D-aspartate receptor encephalitis (anti-NMDAR encephalitis) in children.

Retrospective analysis was performed on the clinical and EEG data of 105 patients with anti-NMDAR encephalitis treated in Beijing Children's Hospital (August 2011-March 2015). Of the 105 patients, 38 were male and 67 were female.The age of onset was from 6 months and 26 days to 15 years and 8 months (average (8±4)years). The time for confirmed diagnosis was from 4 days to 850 days (median 24.5 days). According to the modified Rankin scales, the patient's clinical conditions were assessed and underwent continuous EEG (cEEG) monitoring.The data were reviewed and analyzed.

Based on the severity of the disease, the 105 patients were divided into three groups: mild group (12 cases), moderate group (65 cases), and severe group (28 cases). There were 91 cases(86.7%)with abnormal EEG patterns, including 28 cases (26.7%) with slow background activity in EEG, 25 cases (23.8%) with generalized or diffuse slow waves, 33 cases (31.4%) had focal slow waves, 41 cases (39.0%) had epileptic waves; 10 cases (9.5%) showed unilateral or diffuse alpha-theta band rhythms in nonrapid eye movement (NREM) sleep, 7 cases (6.7%) showed extreme delta brush waves (EDB). Accordingly, the number of patients with abnormal EEG in mild, moderate and severe groups was 5, 58 (89.2%) and 28(100.0%). Seven patients with EDB phenomenon were all in the severe group, and 10 patients with abnormal alpha-theta band rhythms were in the moderate group.

In children with anti-NMDAR encephalitis, the EEG patterns are in line with the changes of EEG in general encephalitis.The extent of EEG abnormalities correlates with the clinical severity of the disease. Extreme delta brush and alpha-theta band rhythms may be suggestive of diagnosis and clinical assessment of the disease.