Anatomy of aphasia revisited
Anatomy of aphasia revisited
复制标题
DOI：
10.1093/brain/awx363
复制
发表时间：
2018-03-01
期刊：
影响因子：
14.5
通讯作者：
Bonilha, Leonardo
中科院分区：
文献类型：
--
作者：
Fridriksson, Julius;den Ouden, Dirk-Bart;Bonilha, Leonardo
在大多数情况下，失语症是由涉及左半球的中风引起的，更广泛的损伤通常与更严重的失语症有关。在西方世界，失语症的经典模型是韦尼克-利希泰姆模型。这个模型已经存在了世纪，失语症的分类仍然依赖于它，然而，更详细的言语和语言在大脑中的定位模型已经被制定出来。在这方面，由Hickok和Poeppel提出的皮质脑组织的双流模型特别有影响力。他们的模型描述了两条处理路径，背侧流和腹侧流，分别大致支持正常受试者的语音产生和语音理解。尽管双流模型在当前的神经心理学研究中有很大的影响，但在这个模型的背景下，对失语症症状的解释相对有限。考虑到双流模型代表了皮层言语和语言组织的一个更微妙的画面，导致失语症损害的皮层损伤应该清楚地映射到双流处理。在这里，我们提出了一个后续研究，我们以前的工作，使用病变数据来揭示支持语音和语言处理的背侧和腹侧流的解剖边界。具体而言，通过强调临床措施，我们研究涉及背侧和腹侧流的皮层损伤和断开对失语症损害的影响。结果表明，运动言语障碍的措施主要涉及背侧流的损害，而受损的言语理解的措施更强烈地与腹侧流的参与。同样重要的是，许多针对命名、言语重复或语法处理等行为的临床测试依赖于两个流之间的相互作用。后一项发现解释了为什么看似不同病变位置的患者在给定的子测试中经常经历类似的损伤。也就是说，这些个体的皮层损伤虽然不同，但会影响广泛的皮层网络，该网络在执行给定的语音或语言任务中发挥作用。目前的数据表明，这是一个更准确的表征比归因于特定的病变部位负责特定的语言缺陷。
In most cases, aphasia is caused by strokes involving the left hemisphere, with more extensive damage typically being associated with more severe aphasia. The classical model of aphasia commonly adhered to in the Western world is the Wernicke-Lichtheim model. The model has been in existence for over a century, and classification of aphasic symptomatology continues to rely on it. However, far more detailed models of speech and language localization in the brain have been formulated. In this regard, the dual stream model of cortical brain organization proposed by Hickok and Poeppel is particularly influential. Their model describes two processing routes, a dorsal stream and a ventral stream, that roughly support speech production and speech comprehension, respectively, in normal subjects. Despite the strong influence of the dual stream model in current neuropsychological research, there has been relatively limited focus on explaining aphasic symptoms in the context of this model. Given that the dual stream model represents a more nuanced picture of cortical speech and language organization, cortical damage that causes aphasic impairment should map clearly onto the dual processing streams. Here, we present a follow-up study to our previous work that used lesion data to reveal the anatomical boundaries of the dorsal and ventral streams supporting speech and language processing. Specifically, by emphasizing clinical measures, we examine the effect of cortical damage and disconnection involving the dorsal and ventral streams on aphasic impairment. The results reveal that measures of motor speech impairment mostly involve damage to the dorsal stream, whereas measures of impaired speech comprehension are more strongly associated with ventral stream involvement. Equally important, many clinical tests that target behaviours such as naming, speech repetition, or grammatical processing rely on interactions between the two streams. This latter finding explains why patients with seemingly disparate lesion locations often experience similar impairments on given subtests. Namely, these individuals' cortical damage, although dissimilar, affects a broad cortical network that plays a role in carrying out a given speech or language task. The current data suggest this is a more accurate characterization than ascribing specific lesion locations as responsible for specific language deficits.