Surgical results of anterior callosotomy on medically intractable epilepsy

We analyzed surgical results of anterior callosotomy (AC) in 27 patients with intractable symptomatic generalized epilepsy or frontal lobe epilepsy. Excellent outcome (decrease in seizure frequency of greater than 80% or no seizure) was obtained in 59.3%, and 14.8% showed good outcome(decrease in seizure frequency of greater than 50%). There was no significant difference of the results between children and adults. AC was more effective on atypical absence, drop attack, head drop attack and generalized tonic-clonic seizure, but decrease in seizure frequency and severity were also observed in other type of seizures. The extent of AC(anterior 1/2 to 4/5) did not influence seizure reduction. However, patients whose seizures onset before 4 years old had a poor outcome. In postoperative EEG, marked lateralization of diffuse bilaterally synchronous spike and wave (SSW) to unilateral hemisphere implied a better prognosis than that of bilateral independent SW. baba