Stereo-electroencephalography (SEEG) in children surgically cured of their epilepsy

Abstract

Purpose: SEEG in children has a low morbidity and leads to a good surgical outcome, in particular in younger patients. We analysed, in detail, the SEEG data of patients that were subsequently cured by surgery.

Methods: We selected the 48 children explored between 2009 and 2013 in our centre and surgically cured after SEEG-based resections with at least one-year follow-up. We retrospectively studied demographic and surgical data and paid particular attention to the data acquired during the invasive recording. Moreover, we compared the children younger than 5 years of age (group 1: 17 children) to those older than 5 years of age at the time of exploration (group 2: 31 patients).

Results: SEEG was well tolerated. Only one patient had slight intracerebral bleeding seen on the post-operative CT-scan without any clinical consequence and which did not prevent the recording. SEEG explored at least four lobes in 59% of patients, either because of a suspected very widespread epileptogenic zone or because of the lack of a precise hypothesis. Auras were recorded only in group 2 (32% of patients, P=0.0009). Despite these difficulties, SEEG led to tailored resections including multilobar resections in 14% and infralobar resections in 69% of patients. The electrical pattern of seizures had no particularities as compared with adults. Interictal spikes and slow waves outside the resection zone were significantly less frequent in group 1 (P=0.02). In symptomatic epilepsies, the lesion matched the irritative zone in only 11% of patients and the ictal onset zone in 32% respectively.

Conclusion: Our study confirms the low morbidity of SEEG in children. SEEG can disclose a limited epileptogenic zone. Our data suggest that the epileptic network is less complex in younger patients, which has to be confirmed by a quantitative analysis of SEEG signals.

Keywords: Children; Chirurgie de l’épilepsie; Electrical stimulations; Enfants; Epilepsy surgery; Explorations invasives; Focal cortical resections; Invasive explorations; Résections corticales focales; Stereo-electroencephalography; Stimulations électriques; Stéréoélectroencéphalographie.