Non-invasive pre-surgical investigation of a 10 year-old epileptic boy using simultaneous EEG-NIRS.

Near-infrared spectroscopy (NIRS) is a novel imaging technique of potential value in the pre-surgical investigation of patients with refractory epilepsy. We recorded simultaneously electrophysiology (EEG; Compumedics, USA) and near-infrared spectroscopy (NIRS; ISS, USA) to examine the localization of the ictal onset zone and assess language lateralization in a young epileptic boy (L.H., 10 years) as part of his pre-surgical evaluation. L.H. underwent a prolonged EEG-NIRS recording while electro-clinical and electrical seizures were recorded. Results were compared to those obtained with other pre-surgical techniques (SPECT, FDG-PET, EEG-fMRI and EEG-MEG) and showed good concordance for ictal onset zone localization. A second NIRS session without EEG was carried out in order to investigate language lateralization. For this purpose, the patient performed a categorical verbal-fluency task during NIRS recordings. Results showed left-hemisphere dominance for language function in this young boy. This case report illustrates that multi-channel EEG-NIRS has the potential to contribute favourably to pre-surgical investigation in young patients.