Right hemisphere grey matter structure and language outcomes in chronic left hemisphere stroke
Right hemisphere grey matter structure and language outcomes in chronic left hemisphere stroke
复制标题
慢性左半球中风的右半球灰质结构和语言结果。
DOI：
10.1093/brain/awv323
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发表时间：
2016-01-01
期刊：
影响因子：
14.5
通讯作者：
Turkeltaub, Peter E.
中科院分区：
文献类型：
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作者：
Xing, Shihui;Lacey, Elizabeth H.;Turkeltaub, Peter E.
左半球中风后语言恢复的神经机制仍然不清楚。虽然较早的证据表明，右半球的语言同源物弥补了左半球语言区的损伤，但目前流行的理论认为，右半球的参与是无效的，甚至是不适应的。使用基于支持向量回归的病变-症状映射和基于体素的形态测量学的新组合，我们旨在确定右半球的局部灰质体积是否独立地影响慢性左半球卒中后的失语症结局。32名左半球卒中失语症幸存者接受了西方失语症成套测验修订版的语言评估和其他认知领域的测试。失语症患者和30名人口统计学匹配的健康对照者获得高分辨率T1加权图像。基于支持向量回归的多变量病变-症状映射被用于识别左半球的关键语言区域，然后量化每个卒中幸存者在这些区域的病变负担。在控制了中风对语言的这些直接影响后，基于体素的形态测量法被用来确定右半球的局部灰质体积是否解释了语言结果的额外差异。在灰质体积与语言结果相关的大脑区域，我们比较了患者和健康对照组的灰质体积，以评估中风后的可塑性。病变-症状映射显示，特定的左半球区域与不同的语言能力。在控制了这些区域的病变负荷、病变大小和人口统计学因素后，右侧颞顶皮层部分区域的灰质体积与自发性言语、命名和重复评分呈正相关。研究领域的一般认知功能是否可以解释这些关系，偏相关表明，这些集群中的灰质体积与语言工作记忆容量有关，但与其他认知功能无关。此外，这些区域的灰质体积在中风幸存者中比健康对照受试者更大。为了证实这一结果，确定了10名无失语症病史的慢性左半球卒中幸存者。有失语症的脑卒中幸存者的右颞顶脑簇灰质体积大于无失语症史的脑卒中幸存者。这些研究结果表明，右半球后背侧流语言同源物的灰质结构独立地有助于语言生产能力在慢性左半球中风，这些地区可能会经历中风后的肥大引起失语症。
The neural mechanisms underlying recovery of language after left hemisphere stroke remain elusive. Although older evidence suggested that right hemisphere language homologues compensate for damage in left hemisphere language areas, the current prevailing theory suggests that right hemisphere engagement is ineffective or even maladaptive. Using a novel combination of support vector regression-based lesion-symptom mapping and voxel-based morphometry, we aimed to determine whether local grey matter volume in the right hemisphere independently contributes to aphasia outcomes after chronic left hemisphere stroke. Thirty-two left hemisphere stroke survivors with aphasia underwent language assessment with the Western Aphasia Battery-Revised and tests of other cognitive domains. High-resolution T-1-weighted images were obtained in aphasia patients and 30 demographically matched healthy controls. Support vector regression-based multivariate lesion-symptom mapping was used to identify critical language areas in the left hemisphere and then to quantify each stroke survivor's lesion burden in these areas. After controlling for these direct effects of the stroke on language, voxel-based morphometry was then used to determine whether local grey matter volumes in the right hemisphere explained additional variance in language outcomes. In brain areas in which grey matter volumes related to language outcomes, we then compared grey matter volumes in patients and healthy controls to assess post-stroke plasticity. Lesion-symptom mapping showed that specific left hemisphere regions related to different language abilities. After controlling for lesion burden in these areas, lesion size, and demographic factors, grey matter volumes in parts of the right temporoparietal cortex positively related to spontaneous speech, naming, and repetition scores. Examining whether domain general cognitive functions might explain these relationships, partial correlations demonstrated that grey matter volumes in these clusters related to verbal working memory capacity, but not other cognitive functions. Further, grey matter volumes in these areas were greater in stroke survivors than healthy control subjects. To confirm this result, 10 chronic left hemisphere stroke survivors with no history of aphasia were identified. Grey matter volumes in right temporoparietal clusters were greater in stroke survivors with aphasia compared to those without history of aphasia. These findings suggest that the grey matter structure of right hemisphere posterior dorsal stream language homologues independently contributes to language production abilities in chronic left hemisphere stroke, and that these areas may undergo hypertrophy after a stroke causing aphasia.