Abstracts

Rationale: CSWS (defined as sleep EEG with spike and wave discharges occupying ≥ 85% of slow wave sleep) is associated with cognitive and/or behavioral regression often with a lasting neuro-developmental impairment and therefore requires prompt and aggressive management. While medical management is an acceptable therapeutic approach, not much is known about the role of epilepsy surgery and its impact upon seizure and cognitive outcome in this population, which we evaluated in this pilot study. Methods: A detailed retrospective review of medical records of 6 patients (3 males) with epilepsy associated with CSWS who underwent epilepsy surgery at Children's Hospital of Michigan over a 15 year period was performed. This included a review of their clinical course, neuropsychological records, neuroimaging and EEG data. Results: Cognitive regression associated with the onset of CSWS was a major consideration for surgery in four children with clinically intractable seizures. In the remaining 2 children who had reasonably well controlled clinical seizures, the primary driving force for surgery was neurocognitive decline in the presence of CSWS. The mean age of seizure onset was 2.3 ± 2.5 years, while CSWS was diagnosed at a mean age of 7.9 ± 3.2 years. Brain MRI was abnormal in 2 patients whereas FDG-PET was abnormal in all 6 patients. The mean age at surgery was 8.7 ± 3.6 years, with an average duration of CSWS prior to surgery being 8.8 ± 8.1 months. Multilobar cortical resections were performed in 3/6 patients, while the other 3 patients underwent subtotal hemispherectomy sparing only the primary sensorimotor cortex. Mean follow-up duration was 6.9 ± 4.3 years. CSWS resolved in all patients after surgery, with significant cognitive improvement noted within 3 months of surgery. All the children showed continued and sustained improvement at the time of last follow-up. Three out of four children with intractable epilepsy became seizure free (ILAE class 1), while one patient had significantly decreased seizure frequency (ILAE class 3). One of the 2 patients with otherwise well controlled clinical seizures was seizure free for 3 years, with an eventual return to pre-surgical seizure frequency (ILAE Class 3), while the other patient achieved seizure freedom (ILAE Class 1). Conclusions: Epilepsy surgery in patients with CSWS is associated with good seizure control and improved neurocognitive outcome. Carefully selected CSWS patients may be amenable to a surgical therapeutic option aimed at improving cognitive function.