Abstracts

RATIONALE: The Rey Auditory Verbal Learning Test (RAVLT) is commonly used to evaluate learning and memory in patients being considered for surgical treatment of epilepsy. Based on the known verbal deficits in patients with resection from the left temporal lobe, patients with a left temporal lobe epileptic focus are expected to perform poorly on this test. In Montreal, over half the patients are francophone, and thus it is necessary to have English and French versions of this test. We undertook to determine whether the expected deficits are indeed present in unoperated patients, whether surgery results in post-operative changes, and whether the language of test administration affects performance. METHODS: We studied consecutive cases of patients who sustained a resection from the left or the right temporal lobe at the Montreal Neurological Hospital in the last ten years and who had been administered the RAVLT. Selection criteria were: IQ of 75 or above, well-lateralized seizure focus, as well as left hemispheric speech dominance. The variables of interest were language (English vs French), side of eventual resection, and pre vs postoperative performance. RESULTS: There were no significant differences according to language of administration. Preoperatively, patients with left-sided focus showed significant forgetting over a 30 minute delay interval; there were no significant differences over the learning trials between left- and right-sided groups. The nature of the deficit changed after surgery. In addition to the previous impairment in delayed recall, a learning deficit was now observed in the left temporal group. CONCLUSIONS: The lack of significant difference between francophone and anglophone patient groups was surprising because in a previous study with 228 college students we demonstrated a small but significant difference. The present findings are encouraging as they show that the language of testing does not have a significant impact on patient performance. Our results also demonstrate that the RAVLT is a useful tool for preoperative evaluation, keeping in mind that, before surgery, the deficit is restricted to delayed recall.