Abstracts

Rationale: Neuropsychological evaluations of epilepsy patients typically include the Boston Naming Test (BNT), a measure of visual confrontation naming that is very sensitive to the lateralization of partial epilepsy. However, this test is language-intensive, and its clinical utility with bilingual and ethnically diverse patients is unclear. We reviewed the BNT scores, demographics and seizure variables of a sample of Hispanic vs. non-Hispanic native English-speaking patients to determine if ethnicity affects BNT scores and the lateralization of seizure onsets.Methods: Records of patients seen in our outpatient clinics in the last 15 years were reviewed. There were 373 patients with localization related partial epilepsy with laterality (146 right, 230 left) confirmed by Video-EEG. There were 81 Hispanics (HP, mean age=42.7±19.8) and 292 non-Hispanics (NH, mean age=42.9±19.8), all of whom were born, raised and educated in the U.S. and were fluent English speakers. Informed consent for archival research was obtained and approved by an independent IRB.Results: The HP group scored significantly (t=-5.70, p<.0001) lower (35.0 ± 12.8) than the NH group (43.8 ± 12.2). A t-test on the BNT between laterality groups across the entire sample was not significant. Although BNT scores for the NH group were equivalent and not significantly different, there was a significant difference for the HS group (t=2.12, p=.037), with higher BNT scores for right onsets (38.4 ± 11.9) than left onsets (32.4 ± 13.0). A 2 (HP/NH) x 2 (laterality R/L) ANCOVA controlling for education and age at onset, both of which correlated significantly with the BNT, was significant (F=32.3, p<.0001). Significant differences were found for ethnic group (F=24.69, p<.0001) and education (F=81.35, p<.0001) but not for laterality, age at onset, or the interaction of ethnic group by laterality. Importantly, the Hispanic group with right hemisphere onsets scored at a level (38.4) that would typically be regarded as very impaired and suggestive of left hemisphere onsets using traditional norms.Conclusions: Hispanics born, raised and educated in the U.S. showed significantly lower BNT scores than the non-Hispanics. This finding could be attributable to Hispanics speaking a mixture of Spanish and English at home, which could affect the acquisition of exact naming of lower frequency items on the BNT. However, only the Hispanic group showed the expected lower scores for left vs. right seizure onsets. Notably, the Hispanics with right hemisphere onsets scored at levels typically found in patients with left hemisphere onsets. These findings should be taken into account when evaluating pre-surgery epilepsy patients, as Hispanics—even if born and raised in the U.S.—could be misclassified as showing left hemisphere dysfunction using traditional norms and classification schemes. Instead, the threshold for suggesting left hemisphere onsets should be adjusted downwards for this population.