Abstracts

Rationale: The Boston Naming Test (BNT), a measure of confrontation naming, has been shown to be sensitive to lateralized dysfunction in adults with epilepsy. However, its application in adolescents with epilepsy has been hampered by the lack of appropriate normative data for this age range. The purpose of this study was to investigate BNT performance in adolescents with complex partial seizures when applying recently collected normative data for this age range (Martielli, Blackburn & Gfeller, 2007). It was predicted that the BNT would effectively lateralize the seizure focus in these patients.Methods: BNT test performance was collected through retrospective record review for 34 patients ages 15 through 18 (mean age = 16.54) referred for baseline testing prior to neurosurgical treatment of their epilepsy. 15 participants had a left hemisphere seizure focus (9 temporal, 6 extra-temporal); 16 participants had a right hemisphere focus (4 temporal, 12 extra-temporal). Three participants had bilateral foci. Verbal IQ (VIQ) was estimated using the Vocabulary subtest from the Wechsler Scale appropriate to age at testing. Performance was evaluated based on BNT raw score and through the use of a cutting score based on the 10th percentile in the normative group to operationally define impairment.Results: Similar to the normative sample, BNT performance was positively correlated with estimated Verbal IQ (Normative group r=0.42; p<.01; Epilepsy group r=0.67; p=.01). Given this correlation, and the finding of significantly lower VIQ in the epilepsy group compared to the normative group (F(1, 231)=34.73, p<.001), VIQ was used as a covariate. As predicted, the epilepsy group performed significantly worse than the normative sample on the BNT when controlling for VIQ (F(1, 230)=27.26, p<.001). Contrary to prediction, the BNT failed to lateralize the seizure foci, with similar mean scores for patients with right and with left foci (F(1, 32)=0.813, p=0.45). 56% of the epilepsy sample had achievement in the impaired range. Impairment rate was highest in the left temporal group (67%) compared with rates < 50% for other foci locations.Conclusions: When applying age appropriate norms, the BNT appears to be sensitive to the impact of epilepsy in late adolescents. However, in the current sample, the BNT lacked the specificity to be used as a marker for lateralized dysfunction. Further investigation of factors contributing to BNT performance in adolescents with and without epilepsy is necessary in order to understand the meaning of impaired naming scores in the adolescents with epilepsy.