Seizure outcome from anterior and complete corpus callosotomy. Eighty patients underwent anterior corpus callosotomy for treatment of generalized seizures. The patients' mean age was 18.3 years (range 4 to 53 years); the mean age at seizure onset was 5.27 years (range 0.1 to 27 years). The mean intelligence quotient (IQ) of 41 testable patients was 71.12 (range less than 30 to 114). The seizure outcome was as follows: 13% were seizure-free, 65% were significantly improved, and 22% were unchanged. Ten patients subsequently underwent a second operation to complete the callosal sectioning which resulted in additional seizure improvement in only five of them. Five complications resulted from 90 operations: two epidural hematomas, one delayed subdural hematoma, one bone-flap infection, and one postcallosotomy disconnection syndrome; two patients died. A younger age at onset of seizures, a higher IQ, and generalized tonic-clonic, atonic, complex-partial, and mixed seizure types were associated with improved seizure outcome. 