Fig. 1

Intracranial EEG during an epilepsy attack shows a leading spike in the electrodes placed between the tip of the temporal lobe and parahippocampal gyrus (A, arrow). The electrodes where the leading spike was observed (B, D) are close to the area where the glutamate concentration was increased on glutamate chemical exchange saturation transfer magnetic resonance imaging. The red circle indicates the electrode at which the spike was detected. The black frame indicates the area to be removed (D). The area where focal ablation of the left temporal lobe tip, temporal lobe base, and middle and inferior temporal gyrus was performed is shown based on the ictal electroencephalography origin area on intracranial electroencephalography (D). The hippocampus was preserved, and the area with increased glutamate concentration depicted on glutamate chemical exchange saturation transfer magnetic resonance imaging (C) was resected (E). Glutamate chemical exchange saturation transfer magnetic resonance imaging shows that glutamate concentrations were the highest in the tip of the temporal lobe, followed by the head of the hippocampus (F). Glu-CEST, glutamate chemical exchange saturation transfer; MRI, magnetic resonance imaging; PHG, parahippocampal gyrus; T-Base, temporal base; F-Base, frontal base; F-Lat, frontal lateral; T-Lat, temporal lateral; P-Lat, parietal lateral; T2WI, T2-weighted imaging