Clinical characteristics and outcome of children with electrical status epilepticus during slow wave sleep

BACKGROUND: Electrical status epilepticus in slow wave sleep (ESES) is a rare, age-related, self-limited disorder characterized as epilepsy with different seizure types, neuropsychological impairment in the form of global or selective regression of cognitive functions, motor impairment, and typical electroencephalographic (EEG) findings of continuous epileptic activity occupying 85% of nonrapid eye movement sleep. AIMS: The aim is to examine the clinical and electrophysiological findings and treatment modalities of children with ESES and to evaluate the outcome of the disorder. MATERIALS AND METHODS: Fourteen patients with a diagnosis of electrical status epilepticus during slow wave sleep and followed-up at least 2 years were included. STATISTICAL ANALYSIS: Pearson correlation test was used in the study. RESULTS: Among the 14 patients, eight of them had normal mental development before ESES. Twelve of the patients mentioned cognitive impairment and decline in school performance during ESES. After ESES, seven patients had mental retardation in different severity. One of these patients was diagnosed with benign partial epilepsy of childhood with centrotemporal spikes and had normal intelligence quotient level prior to ESES. The diagnosis of ESES was made after newly occurred different seizure types in four of the patients while two of the previously known epileptic patients presented with only severe psychiatric impairment. Valproic acid and carbamazepine were the mostly frequently used drugs before the onset of ESES. After at least 2 years of follow-up, seven patients were seizure free, but still taking antiepileptic treatment. Five patients were seizure free, while two of them had ongoing seizures despite antiepileptic therapy. CONCLUSION: ESES should be kept in mind in children with unexplained regression or stagnation of development associated with seizures or not. Sleep EEGs should be performed for timely diagnosis, proper treatment and prevention of permanent cognitive impairment.