Staged Total Callosotomy for Lennox-Gastaut Syndrome: A Case Report
A 6 year-old boy was born at 34 weeks’ gestation to healthy parents with birth weight of 3,540 g after an uneventful pregnancy. He had no family history of epilepsy or focal neurologic sign, but he had delayed development in fine motor and language areas since before 12 months of age. His first seizures, myoclonic seizures, occurred at the age of 8 months, and he was started on antiepileptic drugs (AEDs). At the time of his admission to our hospital at the age of 27 months, he was suffering from multiple types of seizures including drop attacks, generalized tonic seizures, and atypical absence seizures. His EEG showed generalized slow spike and wave discharges with multifocal spikes (), and he was diagnosed as having LGS. Brain magnetic resonance imaging (MRI) showed no abnormalities. Despite various antiepileptic drugs (valproate, topiramate, zonisamide, and clobazam) and a ketogenic diet, his seizures remained uncontrolled. Long term video EEG monitoring for 48 hours showed a dozen seizures a day. The seizure semiology consisted of suddenly dropping his head with losing his tone, thus suggesting myoclonic-atonic seizures. Ictal EEG showed diffuse generalized bursts of polyspike discharges with very brief electromyographic activities. His social quotient was reported to be 27. At the age of 36 months, he underwent anterior 2/3 corpus callosotomy. He achieved a post-operative seizure-free state for 3 months, after which he developed a relapse of his seizures. EEG performed at post-operative 10 months revealed frequent generalized spike and wave discharges and generalized paroxysmal fast activities. His seizures did not respond to either additional vagus nerve stimulation or to medical treatment at that time. As diffusion tensor imaging showed remaining callosal fibers in the splenium, we decided to perform a second total callosotomy (). After the second total callosotomy, the patient maintained a seizure-free state for 27 months and with EEG normalization (). He is still on the medication of valproic acid, topiramate, zonisamide, and clobazam. Developmental test performed after the second surgery showed no remarkable progress by that time. However, according to his parents, his cognitive function is improving compared to that of his pre-operative state.