AN MR PROTOCOL FOR PRESURGICAL EVALUATION OF PATIENTS WITH COMPLEX PARTIAL SEIZURES OF TEMPORAL-LOBE ORIGIN

PURPOSE: To find an optimal diagnostic protocol for the presurgical MR evaluation of patients with temporal lobe epilepsy, METHODS: MR imagi ng in 14 healthy subjects and 25 consecutive patients with temporal lo be epilepsy was performed in paracoronal sections perpendicular to the hippocampi with T1-weighted inversion recovery and T2 weighting. Volu me measurements of the hippocampus/amygdala complex were performed and a multiecho sequence yielded T2-calculated images. RESULTS: Hippocamp al disease was seen in 22 of 25 temporal lobe epilepsy patients on par acoronal T1-weighted inversion recovery images. Four had bilateral abn ormalities. Characteristic for hippocampal disease were features such as volume loss, decreased signal, and loss of internal morphology. Onl y 17 of 25 patients demonstrated hippocampal pathology on T2-weighted images, and in one patient this was bilateral. Patients with only mini mal structural loss on T1-weighted inversion recovery had normal T2-we ighted images, T2 calculation was no more sensitive than visual assess ment on the T2-weighted images. Volume measurements were normal in one patient and misleading in two patients. Lateralization, as compared w ith clinical and electroencephalographic findings, was most confidentl y done with paracoronal T1-weighted inversion recovery images and volu me measurements. CONCLUSIONS: An optimum MR protocol for temporal lobe epilepsy patients is proposed. Its essential feature is that the hipp ocampus be evaluated by paracoronal T1-weighted inversion recovery ima ges and volume measurements. T2-weighted imaging can be omitted.