Abstracts

RATIONALE: Recently, the Wechsler Intelligence and Memory tests have undergone extensive revisions. At present, little is known about the validity of these revised tests in patients with focal epilepsy. Preliminary findings from a prospective series of temporal lobe epilepsy (TLE) and extratemporal epilepsy (ETE) patients administered the WAIS-III and WMS-III are reported. METHODS: There were 35 patients with EEG-confirmed unilateral TLE (left = 23, right = 12), 8 patients with bilateral TLE, and 9 patients with ETE who participated as part of a study examining test-retest reliability of these measures. Groups were compared across Verbal, Performance, and Full Scale IQ from the WAIS-III. Groups were also compared across the eight Primary Memory Index scores of the WMS-III. RESULTS: The four groups were statistically comparable across age, education, age at seizure onset, seizure duration, handedness, and gender. The groups were not statistically different across the WAIS-III Verbal IQ, Performance IQ, and Full Scale IQ scores. Comparing groups across the WMS-III scores a trend was found for lower performance on the Working Memory Index for the ETE patients (mean = 72) compared to the TLE groups (mean = 84). The right TLE group had lower scores across the Visual Immediate (mean = 76) and Delayed (mean = 76) Index scores compared to the other three groups (Immediate mean = 85; Delayed mean = 83). The Auditory Immediate and Delayed Index scores, and General Memory Index score did not distinguish groups. Additional correlation analysis revealed no significant (p > .05) association between seizure onset and either Full Scale IQ (r=.05) or WMS-III General Memory (r= .26). Seizure duration did not significantly correlate with either FSIQ or General Memory. CONCLUSIONS: Examination of this preliminary patient series did not find striking group differences on major indices of the newly revised WAIS-III and WMS-III, although trends were found for lower working memory in ETE and lower visual memory performance in right TLE. Larger samples will be needed to allow more definitive statements regarding test sensitivity in detecting focal cognitive dysfunction.