Abstracts

Rationale: Epilepsy is a common neurological disorder with cognitive and psychiatric comorbidity. About 30-40% of patients with complex partial epilepsy have seizures that are refractory to medication. These patients are candidates for neurosurgical treatment, commonly a temporal lobectomy. Patients with temporal lobe epilepsy (TLE) can exhibit deficits in intellectual functioning, and the presence of cognitive deficits have implications for surgical outcome. The WAIS-IV is the most recent version of a commonly used measure of intellectual function. However, little data are available regarding the performance of patients with known neurological disease on the WAIS-IV (Bauer and Loring, 2010). The current study compares the pre-surgical performance of patients with left TLE (LTLE) to patients with right TLE (RTLE) across the WAIS-IV index and subtest scores Methods: The study included review of epilepsy patients completing a pre-surgical evaluation for medically refractory epilepsy. Participants: Twenty five patients were identified that met study inclusion and exclusion criteria. There were 11 participants diagnosed with left TLE and 14 individuals with right TLE. Variables/Measure(s). All participants completed comprehensive neuropsychological assessment as part of a Phase I presurgical evaluation. Results: The Left TLE group mean age was 36 years (SD = 15.9) and had 12.9 years of education. The mean age of right TLE group was 31 years (SD = 15.9) and had 13.5 years of education. The average FSIQ, VCI, PRI, and PSI indices of the left TLE group significantly differed from the population parameter of 100 (Left TLE, FSIQ = 87.8, VCI=91.0, PRI=89.5, WMI=90.9, PSI=88.7). the average FSIQ, VCI, and PRI index scores of the right TLE group significantly differed from the population parameter of 100 (RTLE; FSIQ=88.4, VCI=88.8, PRI=91.3, WMI=93.3, PSI=93.5). ANOVA revealed no significant differences in presurgical WAIS-IV index or subtest scores between the left and right TLE patients (p>.05). Conclusions: As expected, patients with right and left TLE performed below the average population parameter on the measures of general cognitive, general verbal and general nonverbal abilities (p<.05). The LTLE group also scored significantly below average on a measure of processing speed. However, there was no significant difference between patients with LTLE versus those with RTLE. These data are consistent with past studies using previous versions of the Wechsler Adult Intelligence Scales which demonstrated the WAIS does not reliably lateralize patients with known left or right TLE. Implications for surgical treatment and cognitive outcome are discussed.