Predictors of Intelligence after Temporal Lobectomy in Children with Epilepsy

Performance on standardized measures of intelligence was examined before and after temporal lobectomy in 50 children and adolescents. Group results showed small positive changes in Performance IQ (PIQ), but not Verbal IQ (VIQ). Analyses of individual patients showed that 28% had a significant change in VIQ after surgery, half of whom showed improvements. Increases in VIQ were associated with older age at time of surgery, lower VIQ before surgery, and positive seizure outcome after surgery, whereas longer follow-up time was predictive of smaller change. Increases in PIQ were seen in 25% of patients, and decreases occurred in 8%. Predictors of postoperative change in PIQ were dual pathology and longer follow-up interval, both of which showed negative correlations. Enhanced intellectual function is not one of the benefits to be expected in the majority of children undergoing temporal lobectomy. Further studies are required to determine whether these conclusions may or may not be applied to other aspects of cognitive function.