Effectiveness of total corpus callosotomy for diffuse bilateral polymicrogyria: Report of three pediatric cases.

PURPOSE: Polymicrogyria, a malformation of the cerebral cortex, frequently causes epilepsy. Diffuse bilateral polymicrogyria (DBP) is related to poor epilepsy prognosis, but most patients with DBP are not good candidates for resective epilepsy surgery and effectiveness of corpus callosotomy (CC), a palliative surgery, for patients without resective epileptogenic cortices, has not been established in DBP. Because CC might be effective against DBP-related epilepsy, we conducted total CC in three pediatric DBP cases. METHODS: Case 1. A girl developed epilepsy at 3 months of age, with focal versive seizures and epileptic spasms. The electroencephalogram (EEG) showed a suppression-burst pattern. Total CC was performed at 6 months of age. Case 2. A female infant developed epilepsy on the day of birth, exhibiting epileptic spasms, generalized tonic-clonic seizures, and eye-deviating seizures. She had a history of clusters of tonic seizures. Total CC was performed at 1 year and 2 months of age. After CC, the epileptic focus of the tonic seizures was identified; a secondary resective surgery was conducted. Case 3. A girl developed multiple types of seizures at 3 years of age. Frequent atypical absence status was refractory to antiepileptic drugs. Total CC was conducted at 8 years of age. RESULTS: Case 1: Frequencies of both seizure types decreased. The background EEG changed to continuous high-voltage slow waves. Case 2: Clusters of tonic seizures were well-controlled. Case 3: Atypical absence seizures completely disappeared. CONCLUSION: CC could be effective for patients with DBP, whose habitual seizures include epileptic spasms and absence seizures.