PREOPERATIVE ACTIVATION AND INTRAOPERATIVE STIMULATION OF LANGUAGE-RELATED AREAS IN PATIENTS WITH GLIOMA

OBJECTIVE: Evaluation of the accuracy of preoperative localization of language-related cortex by magnetic resonance imaging-guided positron emission tomography. METHODS: Patients with gliomas in the left domina nt hemisphere were examined preoperatively with magnetic resonance ima ging-guided positron emission tomography and intraoperatively by elect rical stimulation of cortex. RESULTS: A verb generation task yielded m ore intense and better lateralized local increases of cerebral blood f low in the positron emission tomographic examination than did a naming task. Significant correspondence of preoperative and intraoperative f indings was observed for the verb generation task. Cortical sites with aphasic disturbance during electrical stimulation had a significantly higher cerebral blood flow increase during preoperative activation th an did sites without intraoperative language impairment. Areas with ce rebral blood flow increases above an optimum threshold had 73% sensiti vity and 81% specificity to predict aphasic disturbance during intraop erative stimulation. CONCLUSION: The data suggest that with further te chnical improvements, imaging of language function may become a preope rative diagnostic tool for patients with tumors close to language-rela ted brain structures.