EP 22. A sleep surgery of language eloquent brain lesions purely based on rTMS language mapping

Abstract

Objective The resection of left-sided perisylvian brain lesions harbors the risk of postoperative language impairment. Hence, neurosurgeons determine the individual patient’s language distribution by using intraoperative direct cortical stimulation (DCS) during awake surgery. Yet, not all patients qualify for awake surgery. Since non-invasive language mapping by repetitive navigated transcranial magnetic stimulation (rTMS) has frequently shown a high correlation in comparison with the results of DCS language mapping in terms of language-negative brain regions, the present study analyzes oncological and functional outcome of patients who underwent left-sided perisylvian resection of brain lesions purely based on the results of rTMS language mapping. Methods Four patients (astrocytoma WHO grade III of the superior temporal gyrus, astrocytoma WHO grade III of the middle and inferior temporal gyrus, glioblastoma WHO IV of the opercular part of the frontal gyrus, and cavernoma of the insular lobe) underwent rTMS language mapping prior to surgery and data of rTMS language mapping were transferred to the intraoperative neuronavigation system. Preoperatively, 5 days after surgery (=POD5), and 3 months after surgery (=POM3) clinical follow-up was performed. Results No patient suffered from a new surgery-related aphasia. Three patients underwent complete resection immediately, while one patient required a second resection some days later. Conclusion Despite only presenting 4 patients, we could show the feasibility of successfully resecting language-eloquent brain lesions purely based on rTMS language mapping data as a rescue strategy in selected cases in which awake surgery is impossible. No patient was harmed and the extent of resection was oncologically optimal.