Hazem Sally Rosario, Awan Mariam, Lavrador Jose Pedro, Patel Sabina, Wren Hilary Margaret, Lucena Oeslle, Semedo Carla, Irzan Hassna, Melbourne Andrew, Ourselin Sebastien, Shapey Jonathan, Kailaya-Vasan Ahilan, Gullan Richard, Ashkan Keyoumars, Bhangoo Ranjeev, Vergani Francesco
Department of Neurosurgery, King's College Hospital National Health Service Foundation Trust, London, United Kingdom.
King's Neuro Lab, Department of Neurosurgery, King's College Hospital National Health Service Foundation Trust, London, United Kingdom.
Front Neurol. 2021 Mar 10;12:646075. doi: 10.3389/fneur.2021.646075. eCollection 2021.
The simplistic approaches to language circuits are continuously challenged by new findings in brain structure and connectivity. The posterior middle frontal gyrus and area 55b (pFMG/area55b), in particular, has gained a renewed interest in the overall language network. This is a retrospective single-center cohort study of patients who have undergone awake craniotomy for tumor resection. Navigated transcranial magnetic simulation (nTMS), tractography, and intraoperative findings were correlated with language outcomes. Sixty-five awake craniotomies were performed between 2012 and 2020, and 24 patients were included. nTMS elicited 42 positive responses, 76.2% in the inferior frontal gyrus (IFG), and hesitation was the most common error (71.4%). In the pMFG/area55b, there were seven positive errors (five hesitations and two phonemic errors). This area had the highest positive predictive value (43.0%), negative predictive value (98.3%), sensitivity (50.0%), and specificity (99.0%) among all the frontal gyri. Intraoperatively, there were 33 cortical positive responses-two (6.0%) in the superior frontal gyrus (SFG), 15 (45.5%) in the MFG, and 16 (48.5%) in the IFG. A total of 29 subcortical positive responses were elicited-21 in the deep IFG-MFG gyri and eight in the deep SFG-MFG gyri. The most common errors identified were speech arrest at the cortical level (20 responses-13 in the IFG and seven in the MFG) and anomia at the subcortical level (nine patients-eight in the deep IFG-MFG and one in the deep MFG-SFG). Moreover, 83.3% of patients had a transitory deterioration of language after surgery, mainly in the expressive component ( = 0.03). An increased number of gyri with intraoperative positive responses were related with better preoperative ( = 0.037) and worse postoperative ( = 0.029) outcomes. The involvement of the SFG-MFG subcortical area was related with worse language outcomes ( = 0.037). Positive nTMS mapping in the IFG was associated with a better preoperative language outcome ( = 0.017), relating to a better performance in the expressive component, while positive mapping in the MFG was related to a worse preoperative receptive component of language ( = 0.031). This case series suggests that the posterior middle frontal gyrus, including area 55b, is an important integration cortical hub for both dorsal and ventral streams of language.
对语言回路的简单化研究方法不断受到脑结构和连接性新发现的挑战。特别是额中回后部和55b区（pFMG/55b区），在整个语言网络中重新引起了人们的关注。这是一项对因肿瘤切除而接受清醒开颅手术的患者进行的回顾性单中心队列研究。将导航经颅磁刺激（nTMS）、神经纤维束成像和术中发现与语言结果进行关联分析。2012年至2020年间共进行了65例清醒开颅手术，纳入24例患者。nTMS引发了42次阳性反应，其中76.2%位于额下回（IFG），最常见的错误是犹豫（71.4%）。在pMFG/55b区，有7次阳性错误（5次犹豫和2次音素错误）。该区域在所有额回中具有最高的阳性预测值（43.0%）、阴性预测值（98.3%）、敏感性（50.0%）和特异性（99.0%）。术中，有33次皮质阳性反应——额上回（SFG）有2次（6.0%），额中回（MFG）有15次（45.5%），额下回有16次（48.5%）。共引发29次皮质下阳性反应——额下回-额中回深部脑回有21次，额上回-额中回深部脑回有8次。最常见的错误在皮质水平是言语停顿（20次反应——额下回有13次，额中回有7次），在皮质下水平是命名障碍（9例患者——额下回-额中回深部有8例，额中回-额上回深部有1例）。此外，83.3% 的患者术后语言出现短暂恶化，主要在表达成分方面（P = 0.03）。术中阳性反应脑回数量增加与术前较好（P = 0.037）和术后较差（P = 0.029）的结果相关。额上回-额中回皮质下区域受累与较差的语言结果相关（P = 0.037）。额下回的阳性nTMS映射与较好的术前语言结果相关（P = 0.017），与表达成分的较好表现有关，而额中回的阳性映射与术前较差的语言接受成分相关（P = 0.031）。该病例系列表明，包括55b区在内的额中回后部是语言背侧和腹侧通路的重要整合皮质枢纽。
