CORTICAL LOCALIZATION OF TEMPORAL-LOBE LANGUAGE SITES IN PATIENTS WITH GLIOMAS

IN A SERIES of 40 patients undergoing an awake craniotomy for the remo val of a glioma of the dominant hemisphere temporal lobe, cortical sti mulation mapping was used to localize essential language sites. These sites were localized to distinct temporal lobe sectors and compared wi th 83 patients without tumors who had undergone language mapping for t he treatment of intractable epilepsy. In patients with and without tem poral lobe gliomas, the superior temporal gyrus contained significantl y more language sites than the middle temporal gyrus. Both patient pop ulations also had language sites anterior to the central sulcus in the superior temporal gyrus (12-16%). The patients without tumors had sig nificantly more language sites in the superior temporal gyrus, compare d with the superior temporal gyrus of patients with temporal lobe tumo rs. Multiple variables were studied for their effect on preoperative a nd postoperative language deficits and included age, sex, number of la nguage sites, histology, size of the tumor, and the distance of tumor resection margins from the nearest language site. The distance of the resection margin from the nearest language site was the most important variable in determining the improvement in preoperative language defi cits, the duration of postoperative language deficits, and whether the postoperative language deficits were permanent. If the distance of th e resection margin from the nearest language site was > 1 cm, signific antly fewer permanent language deficits occurred. Cortical stimulation mapping for the identification of essential language sites in patient s with gliomas of the dominant hemisphere temporal lobe will maximize the extent of tumor resection and minimize permanent language deficits .