Language mapping and surgical efficacy of multimodal techniques combined with awake anesthesia for gliomas involving Broca′s area

Abstract

Objective To investigate language mapping and surgical efficacy of multimodal techniques combined with awake anesthesia for gliomas involving Broca′s area. Methods A total of 42 patients with gliomas involving Broca′s area underwent surgical resection under awake anesthesia at Department of Neurosurgery, Huashan Hospital, Fudan University from January 2011 to December 2017 and were enrolled into this retrospective study. Language cortical activated areas and subcortical pathways were preoperatively reconstructed for surgical planning with functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) tractography respectively. During the craniotomies, direct electrical stimulation was used to localize language cortical areas and subcortical pathways, and resection of tumor was assisted with intraoperative magnetic resonance image-guided real-time neuronavigation system. According to whether the gliomas invaded ventral premotor cortex (vPMC), the patients were divided into 2 groups. Out of the 42 patients, 24 did not show invasion of vPMC (with merely invasion of posterior inferior frontal gyrus) and 18 did. The language mapping outcomes and surgical efficacy were evaluated and compared. Results Intraoperative language mapping was successfully performed in all patients, and in 34 patients (81.0%) at least 1 positive functional site was detected. Three patients (7.1%) experienced focal seizure attack during the mapping process. Gross total resection was achieved in 25 patients, and subtotal resection in 17. Histopathological results indicated 23 cases of World Health Organization (WHO) grade Ⅱ gliomas, 14 cases of grade Ⅲ gliomas and 5 cases of grade Ⅳ gliomas. Sixteen patients (38.1%) experienced short-term language deficits after surgeries, out of whom 12 recovered in 3 months post operation and 4 (9.5%) did not recover. The median follow-up time was 24 months (6-84 months) in 42 patients.Tumour progression was seen in 14 of the 42 patients, and 11 patients died.Compared to the group with tumors that not invaded vPMC, the group with tumors invading vPMC had higher WHO grades(P=0.011) and higher occurrence of short-term language deficits [10/18 vs. 25.0% (6/24), P=0.044] and shorter progress-free survival (28.4±5.2 months vs. 80.7±3.2 months, P<0.001) and overall survival (38.8±5.8 months vs. 80.8±3.2 months, P<0.001). Conclusions The combination of multimodal techniques and awake anesthesia in the surgical treatment of gliomas involving Broca′s area could help protect the patient′s language function while maximizing the removal of tumors. Among them, tumors with invasion of vPMC may cause a higher rate of short-term speech dysfunction and a worse prognosis than those with merely invasion of posterior inferior frontal gyrus. Key words: Glioma; Broca area; Awake anesthesia; Language mapping; Multimodal techeniques