Abstracts

Rationale: When examining cognitive functioning in epileptic patients with mesial temporal sclerosis (MTS), neuropsychological memory measures (both visual and verbal) are an essential part of the test battery and may assist in lateralizing hemispheric dysfunction. Past research has reviewed multiple measures and a weakness in nonverbal memory measures has been revealed. For instance, in more recent literature the BVMT-R, a task requiring visuoconstructional abilities and visual memory, has demonstrated relative inefficiencies in discriminating between groups of patients with left vs. right temporal lobe seizures. The present study was initiated to examine both verbal (RAVLT) and visual (BVMT-R) memory measures within a RMTS and a LMTS epileptic patient sample.Methods: The samples were taken from 2-year retrospective data of patients who underwent continuous video-EEG monitoring to confirm an epilepsy diagnosis, had radiologically confirmed MTS, and completed neuropsychological testing. Intellectual function was measured with the WASI. Twenty-three patients (10 male) with RMTS were included in the first analysis and 18 patients (8 male) with LMTS were included in the second analysis. Test scores were converted to standard T-scores. Paired t-tests were utilized to compare verbal vs. visual memory within the groups.Results: (1) For the first analysis, the RMTS group’s average age was 37.3 (± 11.6), average education was 12.6 (± 2.6), and average FSIQ was 91.7 (± 17.8). Seizure duration was an average of 24.2 (±13.5) years with a median duration of 25 years. The average T-score on the BVMT-R total learning trial was 33.6 (±11.6) and on the total learning trials of the RAVLT was 44.1 (±12.5). This difference was statistically significant [t(22)=4.31, p < .01]. Similarly, delayed recall was lower on the BVMT-R (35.4 ±14.1) than on the RAVLT (45.7 ±12.1), [t(22) = 4.02, p < 0.01]. However, VIQ (89.4±18.4) was not statistically different from PIQ (95.5±17.1) [t(22)=2.03, p > .05]. (2) The LMTS group had an average age of 39.0 (± 12.1), level of education of 13.1 (±2.0), and FSIQ of 90.9 (±15.2). Within the LMTS group, average T-score on the BVMT-R total learning trial was 41.6 (±13.7) and on the RAVLT it was 45.6 (±15.7); this was not a statistically significant difference [t(22)=1.40, p > .05]. Similarly, delayed recall was not different between the BVMT-R (40.4 ± 15.5) and RAVLT (43.7 ±14.1), [t(22) = 1.04, p > 0.05]. However, VIQ (88.6 ±13.8) was lower than PIQ (96.8 ±16.3), [t(22)=2.82, p < .05]. Conclusions: Within the RMTS group, BVMT-R performance was significantly lower than the RAVLT suggesting the BVMT-R was sensitive to the effects of right MTS. However, these same measures demonstrated a lack of sensitivity in examining visual and verbal memory capacity in the LMTS group; verbal memory performance was not lower than visual. Interestingly, results revealed greater PIQ vs. VIQ in both groups with a statistically significant split in the LMTS group with the WASI abbreviated measure of intellectual function.