Foramen ovale electrodes in the preoperative evaluation of temporal lobe epilepsy in children.
OBJECTIVE
Foramen ovale electrodes (FOEs) can localize the epileptogenic zone in adults with mesial temporal lobe epilepsy (TLE). Our aim was to investigate the feasibility and safety of using FOEs to investigate refractory TLE in children.


METHODS
Thirty-eight children with seizure semiology and video-EEG (electroencephalography) consistent with medically refractory TLE, and/or the presence of a lesion in the temporal lobe, had FOEs inserted. Complications occurring during the monitoring and up to 3 months after surgery and the long-term seizure outcome were registered.


RESULTS
Forty electrodes were placed in 38 patients. The mean age of the patients was 9.8 years (range 2.3-15.4 years). FOEs confirmed a unilateral mesial temporal lobe seizure onset in 14 patients, onset in both FOEs and lateral electrodes in two patients, and onset in the anterior temporal electrodes in only one patient. Six patients had seizures recorded but were not considered surgical candidates; four patients had no seizures recorded, and 11 patients were further investigated with depth electrodes. One patient (2.6%) developed a hematoma in the cheek, and in two patients the electrodes were extracranial but could still be used for recording. Twenty-eight children had a temporal resection; 25 were Engel class I at follow-up.


CONCLUSIONS
FOEs are safe to use in children and provide valuable information on the mesial temporal lobe structures in the preoperative investigation of pediatric TLE. Patient selection for FOE investigation is, however, essential for a conclusive result.
Nilsson
Daniel
D
Institute of Neuroscience and Physiology, Epilepsy Research Group, The Sahlgrenska Academy, Göteborg University, Göteborg, Sweden. daniel.nilsson@neuro.gu.se
Fohlen
Martine
M
Jalin
Claude
C
Dorfmuller
George
G
Bulteau
Christine
C
Delalande
Olivier
O
D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D004567:Electrodes, Implanted / Q000009:adverse effects; D004569:Electroencephalography / Q000379:methods*; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D005240:Feasibility Studies; D005260:Female; D054085:Foramen Ovale; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D019635:Neurosurgical Procedures; D011300:Preoperative Care / Q000379:methods*; D013702:Temporal Lobe / Q000503:physiopathology / Q000601:surgery