Nonconvulsive status epilepticus in children with acute encephalopathy: A prospective observational study

Abstract

Abstract Background: Nonconvulsive status epilepticus (NCSE) in children is underrecognized. Objectives: Assessing the incidence of NCSE in children with acute encephalopathy (AE), clinical description, electroencephalogram (EEG) patterns, and therapeutic response were the objectives. Materials and Methods: Children aged from 6 months to 16 years with AE, Glasgow Coma Scale < 12 were included. Clinical assessment, neurological evaluation, laboratory investigations, cerebrospinal fluid (CSF) analysis, and neuroimaging studies were done. EEG was done for 1 h within 24 h of presentation, repeat EEG on day 3, and continuous EEG monitoring, where needed. Improvement in GCS and EEG determined therapeutic response. Results: Twenty-five (25.51%) of 98 children had NCSE. Altered sensorium (100%), seizures (76.5%), and fever (64.2%) were the common presentation. CSF analysis (61/98) was abnormal in 30 children. There was a significant increase in background slowing (24 to 42, P = 0.001), decrease in sleep markers (42 to 22, P = 0.009), significant decrease in the number of patients with epileptiform discharges (28 to 14, P = 0.036). On day 1, 22 of 25 children had NCSE, 11 had persistence until day 3, three exhibited new appearance on day 3. Generalized discharges (64%) on EEG were common and febrile infection-related epilepsy syndrome (FIRES) (40%) the most common etiology. Signal changes in cortex (n = 7), deep gray matter changes (n = 8), and subcortical and deep white matter changes (n = 10) were the abnormalities on magnetic resonance imaging (MRI). Absence of sleep waves, ictal rhythms on EEG, generalized seizures on day 1 and number of episodes, symmetry, focal seizures, and hyperglycemia on day 3 were significant risk factors for NCSE. Sepsis/systemic inflammatory response syndrome, metabolic causes, trauma, and autoimmune disorders had lower risk of developing NCSE Conclusion: A strong association between clinical seizures and NCSE is demonstrated. The most common etiology for NCSE was FIRES. EEG on day 3 helps in identifying new occurrence of NCSE.