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White matter connectivity reflects clinical and cognitive status in Huntington's disease

journal contribution
posted on 01.05.2014, 00:00 authored by G R Poudel, J C Stout, J F Domínguez D, L Salmon, A Churchyard, P Chua, N Georgiou-Karistianis, G F Egan
Objective: To investigate structural connectivity and the relationship between axonal microstructure and clinical, cognitive, and motor functions in premanifest (pre-HD) and symptomatic (symp-HD) Huntington's disease. Method: Diffusion tensor imaging (DTI) data were acquired from 35 pre-HD, 36 symp-HD, and 35 controls. Structural connectivity was mapped between 40 brain regions of interest using tractography. Between-group differences in structural connectivity were identified using network based statistics. Radial diffusivity (RD) and fractional anisotropy (FA) were compared in the white matter tracts from aberrant networks. RD values in aberrant tracts were correlated with clinical severity, and cognitive and motor performance. Results: A network connecting putamen with prefrontal and motor cortex demonstrated significantly reduced tractography streamlines in pre-HD. Symp-HD individuals showed reduced streamlines in a network connecting prefrontal, motor, and parietal cortices with both caudate and putamen. The symp-HD group, compared to controls and pre-HD, showed both increased RD and decreased FA in the fronto-parietal and caudate-paracentral tracts and increased RD in the putamen-prefrontal and putamen-motor tracts. The pre-HDclose, compared to controls, showed increased RD in the putamen-prefrontal and fronto-parietal tracts. In the pre-HD group, significant negative correlations were observed between SDMT and Stroop performance and RD in the bilateral putamen-prefrontal tract. In the symp-HD group, RD in the fronto-parietal tract was significantly positively correlated with UHDRS motor scores and significantly negatively correlated with performance on SDMT and Stroop tasks. Conclusions: We have provided evidence of aberrant connectivity and microstructural integrity in white matter networks in HD. Microstructural changes in the cortico-striatal fibers were associated with cognitive and motor performance in pre-HD, suggesting that changes in axonal integrity provide an early marker for clinically relevant impairment in HD.

History

Journal

Neurobiology of disease

Volume

65

Pagination

180 - 187

Publisher

Elseveier

Location

Amsterdam, The Netherlands

ISSN

0969-9961

eISSN

1095-953X

Language

eng

Publication classification

C1 Refereed article in a scholarly journal