Purpose: Intellectual disabilities are often associated with bilateral or diffuse morphologic brain damage. The chances of becoming seizure free after focal surgery are therefore considered to be worse in patients with intellectual disabilities. The risk of postoperative cognitive deficits could increase because diffuse brain damage lowers the patient's ability to compensate for surgically induced deficits. Several studies in adult patients have indicated that IQ alone is not a good predictor of postoperative cognitive and seizure outcome. Our study evaluated this subject in children and adolescents.
Methods: Pediatric patients with intellectual disabilities (IQ < or = 70), subaverage intelligence (IQ between 71 and 85), or average-range intelligence (IQ > 85) were matched according to several clinical and etiologic criteria to determine the influence of IQ (N = 66).
Results: No dependency of seizure outcome, postoperative cognitive development, and behavioral outcome on the IQ level was found. All groups slightly improved in attention while memory functions tended to decrease and executive functions were stable. School placement remained unchanged for the majority of patients. Between 67 and 78% were seizure free 1 year after surgery (Engel outcome class I).
Conclusions: IQ alone is not a good predictor of postoperative outcome in pediatric patients with epilepsy. As with patients of average-range intelligence, the decision to operate on patients with a low level of intelligence should depend on the results of the presurgical diagnostics. If the results of the neuropsychological examination indicate diffuse functional impairment, this should not hinder further steps, if all other findings are consistent.