1Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing.
2China National Clinical Research Center for Neurological Diseases, Beijing.
J Neurosurg. 2020 Mar 20;134(3):953-960. doi: 10.3171/2019.12.JNS191987. Print 2021 Mar 1.
The dominant inferior parietal lobe (IPL) contains cortical and subcortical structures that serve language processing. A high incidence of postoperative short-term aphasia and good potential for language reorganization have been observed. The authors' goal was to study the plasticity of the language cortex and language-related fibers in patients with brain arteriovenous malformations (BAVMs) located in the IPL.
A total of 6 patients who underwent microsurgical treatment of an IPL BAVM were prospectively recruited between September 2016 and May 2018. Blood oxygen level-dependent functional MRI (BOLD-fMRI) and diffusion tensor imaging (DTI) were performed within 1 week before and 6 months after microsurgery. Language-related white matter (WM) eloquent fiber tracts and their contralateral homologous fiber tracts were tracked. The Western Aphasia Battery was administered to assess language function. The authors determined the total number of fibers and mean fractional anisotropy (FA) indices for each individual tract. In addition, they calculated the laterality index (LI) between the activated language cortex voxels in the lesional and contralesional hemispheres and compared these indices between the preoperative and postoperative fMR and DT images.
Of the 6 patients with IPL BAVMs, all experienced postoperative short-term language deficits, and 5 (83.3%) recovered completely at 6 months after surgery. Five patients (83.3%) had right homologous reorganization of BOLD signal activations in both Broca's and Wernicke's areas. More fibers were observed in the arcuate fasciculus (AF) in the lesional hemisphere than in the contralesional hemisphere (1905 vs 254 fibers, p = 0.035). Six months after surgery, a significantly increased number of fibers was seen in the right hemispheric AF (249 fibers preoperatively vs 485 postoperatively, p = 0.026). There were significantly more nerve fibers in the postoperative left inferior frontooccipital fasciculus (IFOF) (874 fibers preoperatively vs 1186 postoperatively, p = 0.010). A statistically significant increase in right hemispheric dominance of Wernicke's area was observed. The overall functional LI showed functional lateralization of Wernicke's area in the right hemisphere (LI ≤ -0.20) in all patients.
The authors' findings provide evidence for the functional reorganization by recruiting the right hemispheric homologous region of Broca's and Wernicke's areas, right hemispheric AFs, and left hemispheric IFOFs following resection of IPL BAVMs.Clinical trial registration no.: NCT02868008 (clinicaltrials.gov).
优势顶下小叶（IPL）包含皮质和皮质下结构，这些结构用于处理语言。术后短期失语症的发病率高，且语言具有良好的重组潜能。作者的目标是研究位于 IPL 的脑动静脉畸形（BAVM）患者的语言皮质和语言相关纤维的可塑性。
2016 年 9 月至 2018 年 5 月期间，前瞻性地招募了 6 例接受 IPL BAVM 显微手术治疗的患者。在显微手术后 1 周内和 6 个月时进行血氧水平依赖功能磁共振成像（BOLD-fMRI）和弥散张量成像（DTI）。跟踪语言相关的白质（WM）能纤维束及其对侧同源纤维束。采用西方失语症成套测验评估语言功能。作者确定了每个个体束的纤维总数和平均各向异性分数（FA）指数。此外，他们计算了病变和对侧半球激活语言皮质体素之间的侧化指数（LI），并比较了术前和术后 fMR 和 DT 图像之间的这些指数。
6 例 IPL BAVM 患者均出现术后短期语言障碍，5 例（83.3%）术后 6 个月完全恢复。5 例（83.3%）患者在 Broca 区和 Wernicke 区双侧同源 BOLD 信号激活中均出现右同型重组。病变半球的弓状束（AF）中观察到的纤维多于对侧半球（1905 比 254 纤维，p = 0.035）。术后 6 个月，右侧半球 AF 中可见显著增加的纤维数量（术前 249 纤维，术后 485 纤维，p = 0.026）。术后左侧下额枕束（IFOF）中的神经纤维明显增多（术前 874 纤维，术后 1186 纤维，p = 0.010）。Wernicke 区右侧半球优势明显增加。所有患者的总体功能 LI 显示右侧半球 Wernicke 区的功能偏侧化（LI ≤ -0.20）。
作者的研究结果为 IPL BAVM 切除后，通过招募右侧同源的 Broca 和 Wernicke 区、右侧 AF 和左侧 IFOF，为功能重组提供了证据。临床试验注册号：NCT02868008（clinicaltrials.gov）。
