Mesulam M-Marsel, Thompson Cynthia K, Weintraub Sandra, Rogalski Emily J
1 Cognitive Neurology and Alzheimer's Disease Centre, Northwestern University, Chicago, Illinois 60611, USA 2 Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA 3 Department of Psychology, Northwestern University, Chicago, Illinois 60611, USA
1 Cognitive Neurology and Alzheimer's Disease Centre, Northwestern University, Chicago, Illinois 60611, USA 4 Department of Communication Sciences and Disorders, Northwestern University, Chicago, Illinois 60611, USA.
Brain. 2015 Aug;138(Pt 8):2423-37. doi: 10.1093/brain/awv154. Epub 2015 Jun 25.
Wernicke's aphasia is characterized by severe word and sentence comprehension impairments. The location of the underlying lesion site, known as Wernicke's area, remains controversial. Questions related to this controversy were addressed in 72 patients with primary progressive aphasia who collectively displayed a wide spectrum of cortical atrophy sites and language impairment patterns. Clinico-anatomical correlations were explored at the individual and group levels. These analyses showed that neuronal loss in temporoparietal areas, traditionally included within Wernicke's area, leave single word comprehension intact and cause inconsistent impairments of sentence comprehension. The most severe sentence comprehension impairments were associated with a heterogeneous set of cortical atrophy sites variably encompassing temporoparietal components of Wernicke's area, Broca's area, and dorsal premotor cortex. Severe comprehension impairments for single words, on the other hand, were invariably associated with peak atrophy sites in the left temporal pole and adjacent anterior temporal cortex, a pattern of atrophy that left sentence comprehension intact. These results show that the neural substrates of word and sentence comprehension are dissociable and that a circumscribed cortical area equally critical for word and sentence comprehension is unlikely to exist anywhere in the cerebral cortex. Reports of combined word and sentence comprehension impairments in Wernicke's aphasia come almost exclusively from patients with cerebrovascular accidents where brain damage extends into subcortical white matter. The syndrome of Wernicke's aphasia is thus likely to reflect damage not only to the cerebral cortex but also to underlying axonal pathways, leading to strategic cortico-cortical disconnections within the language network. The results of this investigation further reinforce the conclusion that the left anterior temporal lobe, a region ignored by classic aphasiology, needs to be inserted into the language network with a critical role in the multisynaptic hierarchy underlying word comprehension and object naming.
韦尼克失语症的特点是严重的单词和句子理解障碍。潜在病变部位（即韦尼克区）的位置仍存在争议。在72例原发性进行性失语症患者中探讨了与这一争议相关的问题，这些患者共同表现出广泛的皮质萎缩部位和语言障碍模式。在个体和群体水平上探索了临床解剖学相关性。这些分析表明，传统上包括在韦尼克区内的颞顶叶区域的神经元丢失使单个单词的理解保持完整，并导致句子理解的不一致性损害。最严重的句子理解障碍与一组异质性的皮质萎缩部位有关，这些部位不同程度地涵盖了韦尼克区的颞顶叶成分、布洛卡区和背侧运动前皮质。另一方面，单个单词的严重理解障碍总是与左颞极和相邻的颞前皮质的萎缩高峰部位相关，这种萎缩模式使句子理解保持完整。这些结果表明，单词和句子理解的神经基质是可分离的，并且在大脑皮层的任何地方都不太可能存在一个对单词和句子理解同样至关重要的局限皮质区域。韦尼克失语症中单词和句子理解联合受损的报告几乎完全来自脑血管意外患者，其脑损伤延伸至皮质下白质。因此，韦尼克失语症综合征可能不仅反映了大脑皮层的损伤，还反映了潜在轴突通路的损伤，导致语言网络内的策略性皮质-皮质断开连接。这项研究的结果进一步强化了这样的结论，即左前颞叶这一被经典失语症学忽视的区域需要被纳入语言网络，在单词理解和物体命名的多突触层级中发挥关键作用。
