Abstracts

Rationale: Neuropsychological evaluations of patients with temporal lobe epilepsy (TLE) are an important component of pre-surgical decision-making for pharmacoresistant epilepsy. Previous work have established prior editions of the Wechsler Memory scale and other verbal memory tests are able to identify individuals at increased risk for decline in memory following temporal lobectomy. The Wechsler Memory Scale-4th Ed. (WMS-IV) includes new subtests to measure verbal and nonverbal memory. While holding promise, there is little data providing clinical utility of these tests to lateralize hemispheric dysfunction in patients with known or suspected neurological dysfunction. This study evaluated the ability of the WMS-IV to lateralize left and right TLE patients and compare this to well established memory measures, the Rey Auditory Verbal Learning Test (RAVLT) and the Rey-Osterrieth Complex Figure Test (ROCFT.Methods: Neuropsychological evaluations were conducted in patients diagnosed with TLE by an interdisciplinary epilepsy treatment team. Participants: A total of 22 participants met criteria for inclusion in this study. There were 10 left TLE (LTLE) and 12 right TLE(RTLE) patients. Variables/Measures: All participants completed comprehensive neuropsychological evaluations which included the WMS-IV, RAVLT and ROCFT and intracarotid methohexital (Wada s) testing.Results: There were no significant differences between the LTLE and RTLE groups in demographic variables, disease variables (duration of seizures) or IQ. ANOVA did not identify significant differences between LTLE and RTLE groups in the WMS-IV primary memory indices (Auditory, Visual, Immediate, or Delayed memory). Evaluation of WMS-IV subtests found the patients with LTLE scored significantly worse than patients with RTLE on the WMS-IV Logical Memory immediate delay (p<.05) and Logical Memory long delay (p<0.05) subtest scaled scores. Patients with left TLE scored significantly worse than patients with right TLE on the RAVLT trial 5 and delayed recall (p<0.05). There was no significant difference between groups in ROCFT delayed recall.Conclusions: These data raises questions about the added clinical utility of the WMS-IV beyond the clinical utility provided by the RAVLT which was able to lateralize neurological dysfunction for patients with left TLE. While the WMS-IV nonverbal (visual) memory tasks hold promise, these data fail to find the WMS-IV visual memory index differed between right and left TLE patients. This study is limited by small sample size, and larger samples is needed.