From the Departments of Neuroimaging and Forensic and Neurodevelopmental Sciences (S.J.F., N.D.S., L.D., P.L.L., F.D., M.C.), Natbrainlab, Sackler Institute of Translational Neurodevelopment, Institute of Psychiatry, Psychology and Neuroscience, King's College London, UK; Mesulam Center for Cognitive Neurology and Alzheimer's Disease (E.R., J.S., S.W., M.-M.M.), Department of Psychiatry and Behavioral Sciences (E.R.), and Department of Neurology (M.M.M.), Northwestern University Feinberg School of Medicine, Chicago, IL; Division of Neuroscience and Experimental Psychology, School of Biological Sciences (N.D.S., S.W.), University of Manchester, UK; and Neurobiology of Language Recovery, Aphasia and Neurolinguistics Research Laboratory, Communication Sciences and Disorders, and Neurology (C.T.), Northwestern University, Chicago, IL.
Neurology. 2020 Feb 11;94(6):e594-e606. doi: 10.1212/WNL.0000000000008746. Epub 2020 Jan 29.
To combine MRI-based cortical morphometry and diffusion white matter tractography to describe the anatomical correlates of repetition deficits in patients with primary progressive aphasia (PPA).
The traditional anatomical model of language identifies a network for word repetition that includes Wernicke and Broca regions directly connected via the arcuate fasciculus. Recent tractography findings of an indirect pathway between Wernicke and Broca regions suggest a critical role of the inferior parietal lobe for repetition. To test whether repetition deficits are associated with damage to the direct or indirect pathway between both regions, tractography analysis was performed in 30 patients with PPA (64.27 ± 8.51 years) and 22 healthy controls. Cortical volume measurements were also extracted from 8 perisylvian language areas connected by the direct and indirect pathways.
Compared to healthy controls, patients with PPA presented with reduced performance in repetition tasks and increased damage to most of the perisylvian cortical regions and their connections through the indirect pathway. Repetition deficits were prominent in patients with cortical atrophy of the temporo-parietal region with volumetric reductions of the indirect pathway.
The results suggest that in PPA, deficits in repetition are due to damage to the temporo-parietal cortex and its connections to Wernicke and Broca regions. We therefore propose a revised language model that also includes an indirect pathway for repetition, which has important clinical implications for the functional mapping and treatment of neurologic patients.
结合基于 MRI 的皮质形态学和弥散白质束追踪技术，描述原发性进行性失语症（PPA）患者重复缺陷的解剖学相关性。
传统的语言解剖学模型确定了一个单词重复网络，该网络包括 Wernicke 区和 Broca 区，通过弓状束直接连接。最近的束追踪发现 Wernicke 区和 Broca 区之间存在间接通路，表明顶下小叶在重复中起关键作用。为了测试重复缺陷是否与这两个区域之间的直接或间接通路的损伤有关，对 30 名 PPA 患者（64.27±8.51 岁）和 22 名健康对照进行了束追踪分析。还从直接和间接通路连接的 8 个语言周围区提取皮质体积测量值。
与健康对照组相比，PPA 患者在重复任务中的表现下降，并且大多数语言周围区及其通过间接通路的连接受损增加。在颞顶叶皮质萎缩的患者中，重复缺陷更为明显，间接通路的体积减少。
结果表明，在 PPA 中，重复缺陷是由于颞顶叶皮质及其与 Wernicke 区和 Broca 区的连接受损所致。因此，我们提出了一个修订的语言模型，该模型还包括重复的间接通路，这对神经患者的功能映射和治疗具有重要的临床意义。
