Brain MRI of hippocampal volumetry in patients with refractory temporal lobe epilepsy.

OBJECTIVE: To detect for hippocampal sclerosis presurgically in a group of patients with refractory temporal lobe epilepsy. METHODS: Eighty-four consecutive patients with refractory temporal lobe epilepsy were subjected to brain MRI of hippocampal volumetry. A ratio of smaller to larger hippocampal volume was determined and unilateral hippocampal atrophy (HA) was diagnosed if the ratio is less than 0.91. RESULTS: Unilateral HA was diagnosed in 42 patients (50%) and bilateral HA in 1 patient. Other MRI abnormalities were detected in 18 patients with or without coexisting HA. CONCLUSIONS: Hippocampal sclerosis can be detected presurgically in many patients by brain MRI. Additional abnormalities not detected by brain CT can also be demonstrated.