Outcome after corpus callosotomy in children with injurious drop attacks and severe mental retardation.

Wide variability in patient selection, extent of callosal section and definition of successful outcome between studies make impact of corpus callosotomy on patients with medically refractory epilepsies difficult to interpret. Severe mental retardation is considered to be predictive of unfavorable seizure outcome after callosotomy. Very little attention has been paid on the influence of callosotomy on the psychosocial burden on the patients' families. We evaluated the seizure outcome, and parental perception about change in cognition and behavior of 17 children (median age 9.5 years, range 3.5-18 years) with severe mental retardation (IQ<30 in all, except one) and injurious drop attacks, who have completed >or=1-year postoperative follow-up after callosotomy. Nearly two-thirds of our patients had >or=90% reduction in drop attacks and generalized tonic-clonic seizures. In the one-stage total callosotomy group, 9 of 11 (82%) patients had favorable outcome, compared to 2 of the 6 (33%) in the partial callosotomy group. Absence of generalized epileptiform discharges on the 1-year postoperative EEG was significantly associated with a favorable seizure outcome. The mean duration of epilepsy prior to callosotomy tended to be shorter among patients with favorable seizure outcome. Postoperative complications were trivial and transient. Nearly three-fourths of the parents appreciated improvements in behavior and attentiveness of their children and were satisfied with the outcome. We conclude that, in children with severe mental retardation and injurious drop attacks, total callosotomy can be undertaken as a one-stage procedure with insignificant morbidity and results in highly favorable seizure outcome.