Abstracts

RATIONALE: Mesial TLE(MTLE) has been suggested as antiepileptic drug(AED) resistant. It frequently is associated with mesial temporal sclerosis(MTS). It is not clear whether MTS contributes to the AED resistance and the progressive nature of seizure in MTLE. In order to answer the question, we compared clinical characteristics and seizure outcome(SzOC) between MTLE patients with and without MTS and investigated the alteration of seizure numbers(SzNo) during serial treatment periods in each MTLE groups. METHODS: Forty seven adult patients fulfilling the following criteria of cryptogenic MTLE were recruited in the study; 1) mesial temporal lobe semiology, interictal epileptiform discharges on temporal region with/without MTS on MRI or 2) mesial temporal lobe semiology, normal EEG, MTS on MRI. They were followed for at least 3 years(ys) with an adequate AED treatment. We compared clinical characteristics of epilepsy and seizure free rate(SzFR) or SzNo during 3 ys of AED between patients with and without MTS. Paired comparison of SzNo/1 y or 6 months(m) was performed between serial periods from 1 y before to 3 ys after AED in each MTLE groups. RESULTS: Between patients with and without MTS, clinical characteristics, SzFR and SzNo were not significantly different(P>0.05). In patients with/without MTS, SzFR(%) were as follows : 1st y 11.5/0, 2nd y 26.9/23.8, 3rd y 26.9/28.6, 1st 2 ys 7.7/0, terminal 2 ys 19.2/19.0 and 3 ys 7.7/0. In those with MTS, mean paired differences(MPDs) in SzNo between 1 y prior to AED and 2nd y(33.7), 3rd y(37.4), between 1st y and 3rd y(12.8), between 1st 6 m and 2nd 6 m(10.2) were statistically significant(P<0.05). In those without MTS, MPDs in SzNo between 1 y prior to AED and 1st y(37.7), 2nd y(40.8), 3rd y(42.0) were statistically significant(P<0.05). CONCLUSIONS: The above results may indicate 1) MTLE with or without MTS share a similar epileptogenetic nature, 2) Both MTLE groups demonstrate poor but similar seizure outcome by AED, 3) MTS in MTLE does not reflect a progressive worsening of seizure outcome. We suggest that MTS per se does not contribute to the AED resistance and the progressive nature of seizure in MTLE.