Supplementary Material for: Surgical treatment of Epileptic Encephalopathy with Spike-and-Wave Activation in Sleep associated with polymicrogyria: A case report

Introduction:Epileptic Encephalopathy with Spike-and-Wave Activation in Sleep (EE-SWAS) is a rare childhood-onset epileptic encephalopathy, defined by a typical electrographic pattern with mostly continuous slow spike-wave complexes during non-REM sleep. It may be cryptogenic or secondary to genetic or structural etiology. It might be related to progressive and irreversible cognitive deterioration; under these circumstances, there is an urgency for fast adequate treatment. Polymicrogyria is a common brain malformation and epilepsy can occur in up to 90% of the patients. Extensive polymicrogyria can be a cause of EE-SWAS and treatment refractoriness. In these patients, surgical treatment might be considered. Case Presentation: We report on an eight-year-old child who presented with electrographic findings compatible with EE-SWAS and hemiparesis associated with right hemispheric polymicrogyria who successfully underwent hemispherectomy as primary treatment. Surgery is rarely considered for these patients. Conclusion: This report highlights the importance of considering surgery as an early treatment modality in selected cases