HIGH-RESOLUTION SURFACE-COIL MR OF CORTICAL-LESIONS IN MEDICALLY REFRACTORY EPILEPSY - A PROSPECTIVE-STUDY

PURPOSE: To determine the role of surface-coil MR imaging in evaluatin g medically refractory neocortical partial epilepsy. METHODS: A prospe ctive study of 25 patients with medically refractory neocortical parti al epilepsy was performed. Head- and surface-coil images were reviewed by two neuroradiologists to determine the clarity with which cortical lesions were depicted. The ability of imaging, combined with surface electroencephalograhy (EEG), to locate the suspected epileptogenic zon e was evaluated, RESULTS: Compared with head-coil studies, surface-coi l studies showed four more lesions, caused the most probable diagnosis to be altered in five patients, and better defined the lesions in fou r patients. Of 11 patients with lobar EEG abnormalities, imaging showe d focal cortical abnormalities within the same or adjacent lobe in fiv e and multifocal abnormalities in two. Of six patients with EEG abnorm alities restricted to two adjacent lobes, imaging showed focal cortica l abnormalities in one of these lobes in five patients and multifocal abnormalities in one patient. Of eight patients with a nonfocal EEG, i maging showed focal cortical abnormalities in five and multifocal cort ical abnormalities in one. In two of 13 patients, video/EEG telemetry improved seizure location whereas surface-coil imaging showed focal co rtical lesions in six and provided relevant prognostic information in five. CONCLUSION: Compared with head-toil studies, surface-coil imagin g of the cerebral cortex improved detection and differentiation of foc al cortical lesions in 64% of patients. Video/EEG telemetry improved l ocation in 15% of patients, and surface-coil imaging combined with EEG results provided improved location of the suspected epileptogenic zon e or relevant prognostic information in 85%.