Abstracts

Rationale: Developmental/Epileptic encephalopathy with spike wave activation in sleep (D/EE- SWAS; formerly called Electrical Status Epilepticus in Slow Wave Sleep, ESES) is a group of epileptic encephalopathies with onset in childhood. Historically, ESES is defined as epileptiform discharges occupying greater than 85% of slow wave sleep; however, given the associated cognitive and behavioral difficulties, treatment is often initiated for a spike-wave index greater than 50%. No standardized treatment approach exists, and additionally it remains unclear which patient subpopulations may respond favorably to specific medications.


Methods: Pediatric patients (< 20 years of age), diagnosed with D/EE-SWAS over the past three years in the Epilepsy Monitoring Unit at University of California Los Angeles with a minimum follow-up period of one year were identified. The demographics, comorbid diagnoses (including epilepsy, learning disabilities, autism, or other neuropsychiatric disorders), EEG features, treatment course, and response to treatment were studied.

Results: There were 30 children (36% male, 64% female) identified with D/EE-SWAS, with five excluded due to follow-up time of under one year. Of the included patients, average follow-up was 3.5 years (range 1 to 9.5). Average age of D/EE-SWAS onset was 6 years. Of these patients, 80% had epilepsy, with an average age at seizure onset of 3.87 years. About 33% were diagnosed with autism spectrum disorder, 47% diagnosed with a neurodevelopment disorder excluding autism, and 30% had intellectual disability. The features on the first EEG leading to the diagnosis of D/EE-SWAS was 60% focal spike waves, 24% multifocal, 12% generalized, and 4% combination of the above. The majority (64%) of patients fell in highest spike wave index (SWI) of 75-100%, 20% at the 50-75% range, and 16% at 25-50% range. There was an average of 3.4 medication trials (range 1 to 9). The most common medications trialed were benzodiazepines (clobazam 64% and diazepam 56%), followed by amantadine 36%, brivaracetam 36%, prednisolone 28%, lamictal 20%, and valproate 16%. There were 11 patients (44%) that never achieved a SWI of < 10% during the course of their treatment. Of the 14 patients (56%) who did achieve a SWI < 10%, 24% would later have a recurrence. The medications with the most favorable response were diazepam (7) and clobazam (6). Patients who were trialed on high dose steroid taper (7) tended to not as frequently reach SWI < 10%, had intolerable side effects, and/or had rapid recurrence.


Conclusions: This study supports D/EE-SWAS being a heterogeneous condition. It is likely that specific treatments work better for certain subpopulations; in this study, benzodiazepines were the most likely to have an impact on the spike wave burden in sleep. However, more studies are needed to further our understanding of how to best treat each child with this challenging condition.


Funding: None.