Developmental and/or epileptic encephalopathy with spike-and-wave activation in sleep: A single tertiary center experience

Abstract

Objectives

This study aimed to analyze the clinical characteristics, etiology, neuroimaging, treatment, neurocognitive and EEG outcomes of patients with developmental and/or epileptic encephalopathy with spike-and-wave activation in sleep (D/EE-SWAS).

Methods

Patients diagnosed with D/EE-SWAS, between 2014 and 2021, with a spike-wave index (SWI) ≥50 % in NREM sleep EEG, were analyzed retrospectively. Outcome measures included neurocognitive assessment, SWI, and seizure frequency.

Results

A total of 80 patients were included. Median age at initial admission was 43.5 (0.03–148) months, with seizures as the main symptom in 66 (82.5 %) patients. Median age at D/EE-SWAS onset and follow-up was 92.5 (21.3–193.6), and 86.9 (12–204) months, respectively. At diagnosis, 56 patients had seizures (focal: 13, generalized: 43). Unknown group (36; 45 %) constituted the most common etiology. There was a shift towards benzodiazepines, mostly as a combination therapy, in 58 (72.5 %). At the final visit, 38 (47.5 %) of the patients had favorable cognitive outcome which was correlated with older epilepsy onset (≥3 years), normal neurological examination, unknown etiology, seizure freedom during D/EE-SWAS, normal EEG background, fewer ASMs, shorter D/EE-SWAS duration, SWI response, decreased seizure frequency, and SWAS resolution. EEG recovery occurred in 48 (60 %) (median duration: 24 months), with 12(15 %) achieving complete resolution. Of the patients, 38 (47.5 %) were seizure-free at the end of the study period.

Conclusions

Baseline neurologic examination, age at onset of epilepsy/D/EE-SWAS, etiology, and number of ASMs at diagnosis had an impact on outcomes. Etiology and number of ASMs may serve as parameters to predict treatment response, and underscore the need for tailored approaches for D/EE-SWAS.