Lateralizing seizure focus in presurgical patients with temporal lobe epilepsy: utility of the Ruff-Light Trail Learning Test

From a neuropsychological perspective, left or right temporal lobe abnormalities underlying seizures in patients with temporal lobe epilepsy (TLE) are thought to contribute to selective deficits in verbal or nonverbal memory abilities, respectively. The Ruff-Light Trail Learning Test (RULIT) is specifically designed to detect right hemisphere dysfunction. The purpose of our study was to examine the utility of the RULIT in distinguishing between patients with right (n=20) and patients with left (n=32) TLE in presurgical evaluations. We identified a significant between-group difference in RULIT scores, but not in the expected direction; that is, patients with right TLE had significantly better scores than patients with left TLE. These findings indicate that the RULIT may not be an appropriate test for presurgical epilepsy evaluations. Findings are discussed within the context of results from other lateralizing neuropsychological tests.