Abstracts

Anomalous language dominance (i.e., mixed or right cerebral dominant) is thought to be a good prognostic indicator of language function following surgical resection in the left cerebral hemisphere. Language dominance has also been used to help predict risk for postoperative verbal memory decline, but its predictive value is less well established for postoperative memory decline than for language preservation. Although left hemisphere resections have been associated with significant postoperative verbal memory decline in several investigations, this has not been established in a pediatric epilepsy surgery sample. Thus, the current multicenter investigation examined whether anomalous language dominance has a protective effect against verbal memory loss after left hemisphere resection for the control of intractable epilepsy in children. Forty-five (21 male, 24 female) children, ages 6 [ndash] 16 years, who underwent resective epilepsy surgery in the left hemisphere served as subjects. Children were classified into one of two language dominance groups (Left or Non-left [mixed or right]) on the basis of Wada language evaluation: 34 children were Left hemisphere language dominant and 11were Non-left dominant. Verbal memory was assessed before and 1.8 mean years after surgery (range, 6 months -10 years) using either the Children[rsquo]s Verbal Learning Test or California Verbal Learning Test for Children. 78% of children were seizure-free (Engel Class I) after surgery. There were no significant differences between groups with regard to age, gender, duration of seizure disorder, location (TL vs. ExTL) of surgery, or interval between surgery and postoperative memory assessment. There was a significant pre- to post-surgery verbal memory decline (standard score [SS] pre = 84.9, post = 78.6) among the Left language group and a relative pre- to post-surgery improvement (SS pre = 72.0, post = 81.7) in verbal memory in the Non-left language children ([italic]p[/italic] = .02). This group difference was also evident among individual cases. 68% of Left language dominant children demonstrated verbal memory decline after left hemisphere surgery while 64% of the Non-left children showed postoperative verbal memory improvement ([italic]p[/italic] = .06). Children with anomalous language representation (mixed or right dominant) have a better prognosis for verbal memory outcome following resective epilepsy surgery in the left hemisphere than children with typical (left) language dominance.