Abstracts

RATIONALE:_ Interest of foramen ovale (FO) in presurgical evaluation for epilepsy with temporal involvement in children METHODS: From 6/1997 to 2/2000, 21 patients (12 f, 9 m) 3.1 to 19.1 years (m=11.7) old , have had simultaneous FO-EcoG and scalp-EEG video recordings for presurgical evaluation. All were symptomatic cases. Previous EEG-video showed unilateral onset in 20 cases, bilateral in 1 case. Clinical manifestations were typical of mesial temporal onset in all cases. According to MRI we included in group 1: patients with abnormalities in hippocamp (4 right (R) , 4 left (L) ) and hippocamp and neocortex(2 R, 7 L) , group 2: temporal and extratemporal abnormalities ( 3 R frontal, parietal,sylvius), 1 L parieto-occipital abnormality. Data were recorded with FO electrodes unilateral in 20 cases , bilateral in 1 case, all scalp electrodes of 10-20 system and 2 low temporal additional electrodes , with video monitoring 24h./24h. Average duration's recordings were 4 days. Complications were 1 cheek's haematoma and 1 transient V3 hypoesthesia. RESULTS: 20 patients had 195 complex partial seizures . 1 did not have seizure despite anti epileptic drugs withdrawal. In 12 (70%) patients of group 1 scalp EEG discharges onset with slow waves were lateralized, predominant in temporal. FO-EEG ictal discharges with high frequency low amplitude rhythms or irregular rhythmic theta followed by rhythmic sharpwaves, began prior to or was closely correlated with seizures and/or Scalp EEG discharges onsets. So the origin of seizures were in the mesial temporal lobe (MTL) affected, unilateral in 11 cases, bilateral and alternate in 1 case. We could not conclude in the other 8,(30% of group 1), (100% of group 2) because there were no clear definition of the onset of seizure in 7 cases, or did not affect FO electrodes in 1 case.In 9/ 21 patients this method allowed surgery without any other exploration. All patients are seizure free (followed up 4m to 25m: m=12) CONCLUSIONS: Foramen ovale electrodes recording is useful with no morbidity and it may avoid the neccessity of invasive recording in temporal lobe epilepsy.