Auditory verbal learning test can lateralize hippocampal sclerosis

The ability of the Auditory Verbal Learning Test (AVLT) to lateralize hippocampal sclerosis (HS) in mesial temporal lobe epilepsy (MTLE) was explored in a sample of 50 patients with MTLE-HS (23 right and 27 left). Patients' AVLT scores were adjusted to the demographic characteristics of each individual in accordance with the Portuguese normative data. The laterality of the HS was determined by consensus by two neuroradiologists. ROC curves were used to identify the best AVLT cutoff scores to differentiate right vs. left HS. Diagnostic statistics were applied to different AVLT measures. The study results revealed that four AVLT scores can correctly classify the laterality of HS in the total sample and a sub-group of 39 right-handed patients (Edinburgh Laterality Inventory +100): delayed recall trial (76 and 80%, respectively), delayed recognition trial (64 and 67%, respectively), learning over trials index (64 and 74%, respectively), and long-term percent retention index (68 and 72%, respectively). In right-handed patients, the diagnostic capability of the delayed recall trial was improved by pairing it with the learning over trials index (accuracy of 85%). In sum, AVLT measures of verbal memory differentiate left from right HS in MTLE. The delayed recall trial demonstrated good diagnostic capacity.