Beyond the Arcuate Fasciculus: Damage to Ventral and Dorsal Language Pathways in Aphasia.
Previous regional-based diffusion tensor imaging (DTI) studies focused on impairment of the arcuate fasciculus in aphasia; little is known about the extent to which aphasia severity is affected by damage to both ventral and dorsal language white matter (WM) pathways. To understand whether disconnection of these pathways contributes to clinical symptoms, we assessed the relationship between the alterations of WM integrity and clinical characteristics in acute aphasia after stroke. Eighteen patients with acute aphasia and age-, gender-, and education-matched healthy controls underwent language assessment and DTI scanning. The whole brain unbiased tract-based spatial statistics method was employed to quantitate WM integrity (fractional anisotropy) for both groups. Linear correlation analyses were performed to evaluate the relationship between WM integrity and clinical features. The aphasic patients showed decreased WM integrity in the left inferior fronto-occipital fasciculus/inferior longitudinal fasciculus (IFOF/ILF) and the left uncinate fasciculus, which represents components of ventral language pathway, and the left superior longitudinal fasciculus (SLF), which relates to dorsal language pathway. In addition, WM integrity of the left IFOF and SLF showed a positive correlation with aphasia quotient, performance quotient, and cortical quotient, respectively. These findings suggested that impaired WM integrity in both language pathways not only contributed to language performance, but also to general cognitive status. We suggest that aphasia involves a breakdown of multiple connections of dorsal and ventral streams that directly contributes to language deficits. Damage to these dual-streams may serve as a neuromarker for aphasias after stroke.
Center for Information in BioMedicine, Key Laboratory for Neuroinformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 610054, People's Republic of China.|Department of Stomatology, The Fourth People's Hospital of Chengdu, Chengdu, 610036, People's Republic of China.
Mi
M
Yang
Center for Information in BioMedicine, Key Laboratory for Neuroinformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 610054, People's Republic of China.
Yibo
Y
Li
Center for Information in BioMedicine, Key Laboratory for Neuroinformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 610054, People's Republic of China.
Jiao
J
Li
Center for Information in BioMedicine, Key Laboratory for Neuroinformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 610054, People's Republic of China.
Dezhong
D
Yao
Center for Information in BioMedicine, Key Laboratory for Neuroinformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 610054, People's Republic of China. weiliao.wl@gmail.com.
Wei
0000-0001-7406-7193
W
Liao
Center for Information in BioMedicine, Key Laboratory for Neuroinformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 610054, People's Republic of China. chenhf@uestc.edu.cn.
Huafu
H
Chen
D000328:Adult; D000368:Aged; D016880:Anisotropy; D001037:Aphasia / Q000000981:diagnostic imaging* / Q000209:etiology; D001921:Brain / Q000000981:diagnostic imaging*; D001931:Brain Mapping; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D007802:Language; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000000981:diagnostic imaging*; D009434:Neural Pathways / Q000000981:diagnostic imaging; D020521:Stroke / Q000150:complications / Q000000981:diagnostic imaging*
Aphasia; Dorsal stream; Tract-based spatial statistics; Ventral stream; White matter integrity