6827 Management of seizures and neuropsychological outcomes in children with Electrical Status Epilepticus in Slow wave Sleep (ESES)

Objectives

Electrical status epilepticus in slow wave sleep (ESES) is a rare condition characterized by specific electroencephalographic changes in sleep along with varying degrees of developmental regression and clinical seizures. Our aim was to investigate the response to various treatment modalities in our local cohort followed by a systematic literature review of the same. The secondary aim was to assess variability in symptomatic response to treatment.

Methods

Anonymised patient data was collected from a single centre between 2010 and 2022. Literature review was performed using PubMed to investigate treatment options, outcome measures and response in paediatric patients with ESES. All data was manually inputted and analysed through Excel and R software.

Results

Local cohort: 12 children were diagnosed with ESES, nine of whom had pre-existing seizures on antiseizure medications (ASMs). 11/12 (92%) children received clobazam, 5/12 (42%) received steroids. All patients showed improvement in EEG by 24 months. However, 11/12 (92%) of children had ongoing neuropsychological sequelae such as learning difficulties, with six awaiting psychology assessment. Literature review: Data was collected for 202 patients from 21 articles. 19.3% (39/202) of patients were already on ASMs prior to diagnosis of ESES. Following diagnosis of ESES, patients were commenced on ASMs including benzodiazepines in 44.5% (90/202), steroids in 54.4% (110/202) and sodium valproate in 51.4% (104/202). Outcome measures were broadly characterized as response based on improvement in EEG grade or spike wave index (SWI), neuropsychological symptoms (NPS) and seizure frequency. NPS was assessed using different methodologies including parent questionnaires, IQ scores, standardised tests such as WISC-III, MSCA and school reports. 80.8% (156/193) were described to have a generally good outcome to treatment. Improvement in NPS were seen in 49% (91/185) with relapse of symptoms in 11.3% (21/185). 18.5% (26/140) of patients did not have clinical seizures with ESES. 36.4% (51/140) showed improvement in frequency of seizures. 50% (75/150) showed improvement in SWI in sleep EEG and 26% (39/150) relapsed.

Conclusion

There is variability in choice of treatments and outcome measures for ESES with no standardised guideline at present. Neuropsychological assessment is not easily accessible in the region though it is one of the main outcomes measures used in the literature. Corticosteroids were used most in the data from the literature review though clobazam was used more commonly in the local cohort. We will use this data to inform a best practice regional guideline for ESES management.