Contribution of magnetic resonance imaging in 100 cases of refractory partial epilepsy with normal CT scans

One hundred epileptic patients were included in this study according to the following criteria: intractable partial epilepsy, normal CT scan and focal EEG abnormalities. Eighty-nine patients were suffering from complex partial seizures of temporal or frontal origin, 55 and 34 cases respectively. Eleven patients presented with only simple partial seizures. MRI was abnormal in 31 patients. The abnormalities were: focal T2 increased signal intensity (13 cases) most often temporal (10 cases), cryptic arteriovenous malformation (4 cases), focal T1 and T2 signal abnormality (4 cases), focal atrophy (2 cases) and multiple abnormal T2 signals scattered in the white matter (8 cases). The site of MRI abnormalities was consistent with electroclinical data in 22 patients, of whom 20 had a temporal lobe epilepsy. Thus MRI proved to be more often abnormal in temporal than in frontal lobe epilepsy (36 p. 100 and 5.9 p. 100 respectively) when the CT scan is normal. However MRI data, particularly focal T2 hypersignals should be confronted to electroclinical and metabolic findings whenever functional surgery is considered.