Abstracts

Small portion of the mesial temporal lobe epilepsy (MTLE) patients showed a remission for a while with medical treatment although anticonvulsants could not be withdrawn completely. The extent of decreased glucose metabolism in temporal lobe (TL) of MTLE with medical remission might be different from those of MTLE with medical intractability if the glucose metabolism of temporal lobe as a substrate of epileptogenesis might be related to the prognosis. We tried to reveal the difference of the area of decreased glucose metabolism in temporal lobe depending on the medical prognosis in MTLE patients., 140 MTLE with unilateral mesial temporal sclerosis (MTS) were analyzed from brain MRI and clinical data base. Patient with dual lesion and history of central nervous infection was excluded. Patients on seizure free or yearly based rare aura for at least 2 years were termed as group A, in contrast, remaining medically intractable patients as group B. ^18FFDG-PET was done in all 13 of group A [mean F/U D.; 121.4 mon. (27-189 mon) and mean seizure free D.; 58 mon. (24-149)] and done in 51 of group B. The area of interest was mainly divided into medial (MTL) and lateral temporal lobe (LTL) by visual analysis. Involvement of extratemporal cortex and subcortical area such as thalamus were also included., 13/140 (9.3 %) were satisfied with the criteria of the group A. Unilateral involvement of TL was 10/13 (76.9 %) in group A and 46/51 (90.2 %) in group B respectively. 26/46 (56.5 %) with unilateral involvement of TL in group B showed decreased glucose metabolism in both MTL and LTL, compared to 3/10 (30 %) in group A. 15/26 showing involvement in both MTL and LTL in group B also revealed decreased glucose metabolism in extratemporal cortical area but none in group A. Ipsilateral thalamic involvement was 4/10 in group A and 6/46 in group B respectively., The MTL involvement without LTL was suggestive of a good prognostic factor including none involvement of extratemporal cortical involvement, even in unilateral involvement of glucose metabolism in MTLE patient. Interestingly, ipsilateral thalamic involvement was much more prominent in good prognostic group.,