Developmental and/or Epileptic Encephalopathy with spike-wave activation in sleep (D/EE-SWAS),refers to a spectrum of conditions that are characterized by the EEG feature of spike-wave activation in sleep, share similar clinical features and management implications. This syndrome now incorporates several syndromes previously named Landau-Kleffner syndrome, Epileptic Encephalopathy with Continuous Spike-Wave in Sleep and Atypical Benign Partial Epilepsy (pseudo-Lennox syndrome)and it is recommended that these terms no longer be used[1].
Resolution of SWAS on EEG often leads to neurocognitive and behavioral improvement. Many patients have residual disability, limiting independence in around half of them. Cognitive result is primarily influenced by D/EE-SWAS length and etiology, with higher risk of poor outcome for those with the condition for over 2 years . Younger onset of D/EE-SWAS is associated with worse results.