Figure 3
(A) Representative images of patient 40. Preoperative axial T2-weighted magnetic resonance images showing a high-intensity mass lesion mainly in the left insular lobe that extended widely to the left inferior and middle frontal gyrus in a 27-year-old, right-handed woman with no relevant medical history. She presented with convulsive attacks and was transferred to a nearby hospital in December 2017. She was then referred to the authors’ hospital to undergo tumor removal using awake surgery. (B) Preoperative three-dimensional images obtained with navigated repetitive transcranial magnetic stimulation (nrTMS) language mapping using the picture-naming task. Semantic paraphasia was induced in the triangular part of the inferior frontal gyrus (yellow arrow) and the dorsolateral prefrontal cortex (DLPFC) (yellow arrowhead). Anomia was induced in the posterior part of the middle frontal gyrus (white arrowhead). These responses are in conflict with the intraoperative image (Fig. 5D) showing cortical mapping with direct cortical stimulation (DCS). (C) Postoperative sagittal fluid-attenuated inversion recovery-weighted magnetic resonance imaging revealing subtotal mass resection using awake brain mapping. The patient exhibited transient postoperative language impairments and motor paralysis. (D) Stimulation over the precentral gyrus induced speech arrest (number tag: 1, 7); stimulation over the dorsal premotor cortex induced speech slowness (number tags: 2, 3); stimulation over the opercular and triangular part of the inferior frontal gyrus induced no speech disturbance. Using direct cortical stimulation (DCS), language disturbances were detected in the precentral gyrus in the upper part of the tumor (number tag: 7), where language functions might have been moved from the opercular and triangular part of the inferior frontal gyrus. Stimulation over the posterior portion of the superior temporal gyrus induced phonemic paraphasia (number tags: 4, 5, 9); arrow, sylvian fissure. (E) Schematic diagram showing the intraoperative DCS language mapping.
