A case of developmental and epileptic encephalopathy with spike-and-wave activation in sleep with structural etiology treated with corpus callosotomy

Developmental and epileptic encephalopathy with spike-and-wave activation in sleep (DEE-SWAS) is often refractory to antiseizure medications and steroids, and a longer disease duration is associated with intellectual disabilities. Surgical treatment is sometimes performed; however, there have been few reports of corpus callosotomy. The patient was a 5-year-old girl; at 16 months of age, she experienced seizures that began in her left upper limb and then spread throughout her body. Since then, she has had recurrent episodes. Electroencephalography (EEG) revealed spike-and-wave discharges in the right occipital region. Brain magnetic resonance imaging showed right ventricular enlargement and hemosiderin deposition in the right thalamus. Around the age of 3, she became hyperactive and unable to speak. At 4 years of age, atypical absence seizures appeared and EEG during sleep showed continuous generalized spike-and-wave complexes, leading to the diagnosis of DEE-SWAS. At the time of diagnosis, her developmental quotient (DQ) was 51. However, despite medical treatment, including adrenocorticotropic hormone therapy, she was resistant to these interventions, and her DQ decreased to 39 within approximately 1 year. A total corpus callosotomy was performed at the age of 5 years and 5 months. Postoperatively, epileptic seizures were controlled and the epileptiform discharges was lateralized to the right hemisphere. Additionally, developmental improvements were observed, including increased speech and the ability to anticipate the need for defecation. Early corpus callosotomy can improve seizures and intellectual outcomes in patients with drug-resistant DEE-SWAS with focal lesions that can take time to resolve spontaneously.