Abstracts

Temporal lobe epilepsy (TLE) is the most common form of medically intractable partial epilepsy in adults, and surgery (anterior temporal lobectomy or a selective amygdalo hippocampectomy) is effective in the majority of patients. We have developed since 1998 a new surgical technic to treat non lesional TLE which consists in disconnecting the whole temporal lobe from the insula and surrounding structures. The aim of this study was to assess the safety and results of temporal surgical disconnection of patients suffering from non lesional TLE., Since 1998 , 62 patients suffering from TLE, or extra TLE have been treated by surgical disconnection of the epileptogenic zone. Among this group, 45 patients (mean age: 35 y [plusmn] 10) suffered from TLE and underwent temporal disconnection (left and right disconnection in 20 and 25 patients respectively). There was 16 males and 29 females, 12 were left handed and 33 were right handed. All patients underwent a comprehensive pre-surgical evaluation with MRI, chronic video-EEG recording and neuropsychological assessment. 16 patients ( 35 %) underwent pre-surgical evaluation with depth electrodes (SEEG). All patients underwent a post operative MRI, neuropsychological testing, repeated scalp EEG and visual field examination. Temporal disconnection was performed under neuronavigation and consisted in disconnecting the lateral temporal neocortex, the whole hippocampus, para-hippocampus and the amygdala. Veins and arteries were spared in order to avoid post-operative temporal lobe ischemia and subsequent temporal lobe swelling., At two years follow-up, 84.4 % of patients were Engel[apos]s I ( 58 % were Ia ). Four patients were class II and 3 class IV. Post-operative clinical morbidity was as follow: persistent mild hemiparesia (n =1) or mild facial paresia (n=1), definitive quadranopsia (n= 23), hemianopsia ( n= 1). In dominant temporal lobe, verbal memory was worsened in 69 %. Radiological post-operative morbidity was as follow: 2 thalamic or pallidal limited ischemia without clinical consequences, 2 temporal horn cystic dilatation (one requested reintervention without clinical consequences). At 6 months and one year follow up, scalp EEG showed temporal spikes respectively in 27 % and 19 % of non cured patients compared to 8.5 % and 6 %of patients seizure free., Temporal disconnection was effective in 85% of patients (Engel[apos]s Class I). Post [ndash]operative mild contro-lateral motor deficit was found in about 4 %, quadranopsia in 51 % and verbal memory deficit in dominant hemisphere in about 69 %. Presence of spikes in post-operative scalp EEG was less frequent in patients seizure free.
Comparative studies are required to evaluate temporal disconnection as an alternative to lobectomy in non lesional TLE.,