Etiological associations and outcome predictors of acute electroencephalography in childhood encephalitis.

Abstract Objectives To examine EEG features in a retrospective 13-year cohort of children with encephalitis. Methods 354 EEGs from 119 patients during their admission were rated blind using a proforma with demonstrated inter-rater reliability (mean k =0.78). Patients belonged to 12 etiological groups that could be grouped into infectious and infection-associated ( n =47), immune-mediated ( n =36) and unknown ( n =33). EEG features were analyzed between groups and for risk of abnormal Liverpool Outcome Score and drug resistant epilepsy (DRE) at last follow up. Results 86% children had an abnormal first EEG and 89% had at least one abnormal EEG. 55% had an abnormal outcome, and 13% had DRE after median follow-up of 7.3years (2.0–15.8years). Reactive background on first EEGs (9/11, p =0.04) and extreme spindles (4/11, p p Mycoplasma (1/10), other viral (1/10) and other unknown (1/28) encephalitis, was most predictive of DRE after multivariable analysis (OR 11.9, p Conclusions Non-reactive EEG background and the presence of shifting focal seizures resembling migrating partial seizures of infancy are predictors of abnormal outcome and DRE respectively in childhood encephalitis. Significance EEG is a sensitive but non-discriminatory marker of childhood encephalitis. We highlight the EEG features that predict abnormal outcome and DRE.