Sargent College of Health & Rehabilitation Sciences, Boston University, Boston, MA, USA; School of Medicine, Boston University, Boston, MA, USA.
Brain Connectivity and Behaviour Laboratory, Sorbonne Universities, Paris, France; Groupe d'Imagerie Neurofonctionnelle, Institut des Maladies Neurodégénératives-UMR 5293, CNRS, CEA University of Bordeaux, Bordeaux, France.
Cortex. 2022 Oct;155:90-106. doi: 10.1016/j.cortex.2022.06.016. Epub 2022 Jul 19.
Inconsistent findings have been reported about the impact of structural disconnections on language function in post-stroke aphasia. This study investigated patterns of structural disconnections associated with chronic language impairments using disconnectome maps. Seventy-six individuals with post-stroke aphasia underwent a battery of language assessments and a structural MRI scan. Support-vector regression disconnectome-symptom mapping analyses were performed to examine the correlations between disconnectome maps, representing the probability of disconnection at each white matter voxel and different language scores. To further understand whether significant disconnections were primarily representing focal damage or a more extended network of seemingly preserved but disconnected areas beyond the lesion site, results were qualitatively compared to support-vector regression lesion-symptom mapping analyses. Part of the left white matter perisylvian network was similarly disconnected in 90% of the individuals with aphasia. Surrounding this common left perisylvian disconnectome, specific structural disconnections in the left fronto-temporo-parietal network were significantly associated with aphasia severity and with lower performance in auditory comprehension, syntactic comprehension, syntactic production, repetition and naming tasks. Auditory comprehension, repetition and syntactic processing deficits were related to disconnections in areas that overlapped with and extended beyond lesion sites significant in SVR-LSM analyses. In contrast, overall language abilities as measured by aphasia severity and naming seemed to be mostly explained by focal damage at the level of the insular and central opercular cortices, given the high overlap between SVR-DSM and SVR-LSM results for these scores. While focal damage seems to be sufficient to explain broad measures of language performance, the structural disconnections between language areas provide additional information on the neural basis of specific and persistent language impairments at the chronic stage beyond lesion volume. Leveraging routinely available clinical data, disconnectome mapping furthers our understanding of anatomical connectivity constraints that may limit the recovery of some language abilities in chronic post-stroke aphasia.
关于结构性断开对中风后失语症语言功能的影响，已有研究结果不一致。本研究使用连接组图谱调查了与慢性语言障碍相关的结构性断开模式。76 名中风后失语症患者接受了一系列语言评估和结构磁共振成像扫描。支持向量回归连接组-症状映射分析用于检查连接组图谱（代表每个白质体素的断开概率）与不同语言分数之间的相关性。为了进一步了解显著的断开是否主要代表局灶性损伤还是病变部位以外的似乎保存但断开的区域的更广泛网络，将结果与支持向量回归损伤-症状映射分析进行定性比较。失语症患者中有 90%的左侧大脑皮质周围网络的部分白质同样断开。在这个共同的左侧皮质周围连接组周围，左侧额颞顶叶网络的特定结构断开与失语症严重程度以及听觉理解、句法理解、句法产生、重复和命名任务的较低表现显著相关。听觉理解、重复和句法处理缺陷与在 SVR-LSM 分析中具有显著意义的病变部位重叠和延伸的区域的断开有关。相比之下，由于 SVR-DSM 和 SVR-LSM 结果在这些评分上高度重叠，失语严重程度和命名所衡量的整体语言能力似乎主要由岛叶和中央脑回皮质的局灶性损伤来解释。虽然局灶性损伤似乎足以解释语言表现的广泛测量，但语言区域之间的结构断开为病变体积之外的慢性阶段特定和持续的语言障碍的神经基础提供了额外信息。利用常规临床数据，连接组图谱进一步加深了我们对解剖连通性限制的理解，这些限制可能限制了一些中风后失语症患者语言能力的恢复。
