[Staged total callosotomy for medically intractable seizures]

For the treatment of intractable generalized epilepsies, two-staged total callosotomy was performed in five patients. In all patients, preceded anterior callosotomy failed to obtain satisfactory seizure control. All patients showed mental retardation with various degrees. Mean age at the first operation was 10.2 years and 4 patients were operated in their childhood. All patients showed various types of seizures; drop attack (DA) in 3 patients, tonic seizure (TS) in 2, myoclonus (MY) in 2, complex partial seizure (CPS) in 2, atypical absence (AA) in 1, and head drop (HD) in 2. After anterior callosotomy, complete cessation of CPS and 50-80% reduction of DA was obtained in one, respectively. However, only less than 50% reduction of seizures was obtained in other types of seizures. Two years after anterior callosotomy, posterior portion of the corpus callosum was divided. After staged total callosotomy, complete cessation of DA was obtained in all patients and 80-100% reduction of AA was obtained in one patient. One adult patient showed the disconnection syndrome which did not affect activities of his daily life. Our study revealed the efficacy of posterior callosotomy in DA patients with unsatisfactory results after anterior callosotomy. This strategy should be considered especially in childhood cases, since obvious complication was not observed in such cases.