title: Determination of epileptic focus side in mesial temporal lobe epilepsy using long-term noninvasive fNIRS/EEG monitoring for presurgical evaluation.
abstract: Noninvasive localization of an epileptogenic zone is a fundamental step for presurgical evaluation of epileptic patients. Here, we applied long-term simultaneous functional near-infrared spectroscopy (fNIRS)/electroencephalogram (EEG) monitoring for focus diagnosis in patients with mesial temporal lobe epilepsy (MTLE). Six MTLE patients underwent long-term (8-16 h per day for 4 days) fNIRS/EEG monitoring for the occurrence of spontaneous seizures. Four spontaneous seizures were successfully recorded out of the six patients. To determine oxy-Hb amplitude, the period-average values of oxy-Hb across 20 s from the EEG- or clinically defined epileptic onset were calculated for both hemispheres from the simultaneously recorded fNIRS data. The average oxy-Hb values for the temporal lobe at the earlier EEG- or clinically defined epileptic onsets were greater for the epileptic side than for the contralateral side after EEG activity suppression, spike train, and clinical seizure in all four cases. The true laterality was determined based on the relief of seizures by selective amygdalo-hippocampectomy. Thus, oxy-Hb amplitude could be a reliable measure for determining the epileptic focus side. Long-term simultaneous fNIRS/EEG measurement serves as an effective tool for recording spontaneous seizures. Cerebral hemodynamic measurement by fNIRS would serve as a valuable supplementary noninvasive measurement method for presurgical evaluation of MTLE.
authors.affiliation: Jichi Medical University , Department of Neurosurgery, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan.
authors.forename: Edmi Edison
authors.initials: EE
authors.lastname: Rizki
authors.affiliation: Jichi Medical University , Center for Development of Advanced Medical Technology, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan ; Chuo University , Research and Development Initiatives/Faculty of Science and Engineering, 1-13-27 Kasuga, Bunkyo, Tokyo 112-8551, Japan.
authors.forename: Minako
authors.initials: M
authors.lastname: Uga
authors.affiliation: Jichi Medical University , Center for Development of Advanced Medical Technology, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan ; Chuo University , Research and Development Initiatives/Faculty of Science and Engineering, 1-13-27 Kasuga, Bunkyo, Tokyo 112-8551, Japan.
authors.forename: Ippeita
authors.initials: I
authors.lastname: Dan
authors.affiliation: Jichi Medical University , Department of Neurosurgery, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan ; Chuo University , Research and Development Initiatives/Faculty of Science and Engineering, 1-13-27 Kasuga, Bunkyo, Tokyo 112-8551, Japan.
authors.forename: Haruka
authors.initials: H
authors.lastname: Dan
authors.affiliation: Jichi Medical University , Center for Development of Advanced Medical Technology, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan ; Chuo University , Research and Development Initiatives/Faculty of Science and Engineering, 1-13-27 Kasuga, Bunkyo, Tokyo 112-8551, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Tsuzuki
authors.affiliation: Jichi Medical University , Department of Neurosurgery, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan.
authors.forename: Hidenori
authors.initials: H
authors.lastname: Yokota
authors.affiliation: Jichi Medical University , Department of Neurosurgery, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan.
authors.forename: Keiji
authors.initials: K
authors.lastname: Oguro
authors.affiliation: Jichi Medical University , Department of Neurosurgery, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan ; Jichi Medical University , Center for Development of Advanced Medical Technology, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan.
authors.forename: Eiju
authors.initials: E
authors.lastname: Watanabe
keywords: electroencephalography; ictal cerebral hemodynamic response; long-term monitoring; mesial temporal lobe epilepsy; optical topography; spontaneous seizures