Brain temperature measurements during speech in patients with brain tumors: New methods for identification of the speech area in intraoperative brain mappings

In the present study, the usefulness of a functional thermography (fTG) for determining critical speech area was assessed in three patients with brain tumors in language areas. The results of the fTG were also compared with functional MRI (fMRI), subdural electrodes and intraoperative cortical stimulations. Measurements of the regional brain temperature were done using the thermography. The temperature increased after 8-10 s later from the speech and decreased with a few seconds delay after interruption of the task. The areas of increased temperature were coincident with the bridging veins and functional areas identified using fMRI and direct cortical stimulations. The use of fTG increases the sensitivity and specificity for the detection of essential motor language area.