Abstracts

LTL of left language dominant patients for the treatment of intractable epilepsy has rarely resulted in frank aphasic symptomatology, provided the resection remains anterior to primary language cortex identified by electrical stimulation. However, recent reports have documented that some decline in language processing including visual confrontation naming is frequently present in these patients postoperatively. The possibility that BL representation as determined by the Intracarotid Amobarbital Procedure (IAP) might be associated with some sparing of these deficits has been reported for pediatric patients, but to date, has not been evaluated in an adult population. The present study compares the postoperative language outcome of adult patients with BL to a similar group of LTL patients with left hemisphere language dominance (LD). The records of 39 patients who had undergone LTL, IAP and neuropsychological testing pre and postoperatively were reviewed. 26 patients were LD, while 12 had BL. The two groups did not differ in age at surgery (x=29.6 yrs.), education (x=13.4 yrs.) or Full Scale IQ (x=92.4). 50% of LD and 75% of BL patients had early seizure onset ([lt]13 yrs.). A majority of patients underwent language mapping with cortical stimulation prior to surgery. Neuropsychological variables included measures of vocabulary, abstract verbal reasoning, visual confrontation naming, phonemic verbal fluency and category fluency. Pre to postoperative difference scores were calculated for each variable and the two language groups compared for absolute level of performance and degree of change using paired t-tests. Individual change scores for each patient were also reviewed, with significant decline defined by the Reliable Change Index or a drop of one standard deviation or more on at least one language measure. As a group, BL and LD patients performed similarly on language measures both before and after LTL. A significant difference was found on confrontation naming postoperatively, with the LD patients scoring lower than the BL patients (p[lt].05). For both groups, postoperative performance and pre-post change scores suggested greater impairment for patients with late seizure onset. 65% of LD patients and 50% of BL patients declined on at least one language measure. Among BL patients, postoperative language decline was less for patients with higher right hemisphere language scores on IAP. The presence of BL in association with early seizure onset may predict a better language outcome following LTL . This effect appears to be maximized in patients with relatively greater right hemisphere language.