TEMPORAL-LOBE EPILEPSY WITH VARYING SEVERITY - MRI STUDY OF 222 PATIENTS

MRI was performed in 222 consecutive adult patients with temporal lobe epilepsy of varying severity from January 1991 to May 1993. The diagn osis of hippocampal sclerosis was established visually by three indepe ndent observers. The accuracy of visual assessment of hippocampal asym metry was compared with volumetric measure Neuropathological correlati ons were obtained in 63 patients with refractory seizures. Temporal lo be abnormalities were observed in 180 patients (81 %) as follows: hipp ocampal sclerosis in 122 (55 %); developmental abnormalities in 16 (7. 2 %); tumours in 15 (6.8 %) scars in 11 (5 %); cavernous angiomas in 1 0 (4.5 %); miscellaneous lesions in 6. MRI was normal or showed unrela ted changes in 42 patients (19 %). Visual assessment correctly lateral ised hippocampal sclerosis in 79 of the 84 patients measured (94 %), T emporal lobectomy confirmed the MRI data (side and aetiology) in all 5 3 operated patients. Patients with normal MRI had an older age of seiz ure onset and were more often drug-responsive than patients with hippo campal sclerosis. MRI showed temporal lobe abnormalities in 81 % of ep ileptic patients with varying severity with good neuropathological cor relation. Patients with normal MRI had a less severe form of the disea se.