title: White matter microstructural characteristics in newly diagnosed Parkinson's disease: An unbiased whole-brain study.
abstract: Parkinson's disease (PD) is a debilitating neurodegenerative disorder. Findings on specific white matter (WM) alterations in PD have been inconsistent. We hypothesized that WM changes occur in early PD patients and unbiased whole-brain analysis may provide additional evidence of pathological WM changes in PD. In this study, we examined various indexes of WM microstructure in newly diagnosed PD patients at the whole-brain level. 64 PDs with Hoehn &Yahr stage 1 (HY1PDs), 87 PDs with Hoehn &Yahr stage 2 (HYPD2s), and 60 controls (HCs) were recruited. Tract-based spatial statistics (TBSS) and diffusion connectometry were used to identify changes of WM pathways associated with PD. There were no significant differences in axial diffusivity, but HY1PDs exhibited greater fractional anisotropy (FA) and decreased mean and radial diffusivities (MD and RD) in callosal, projection, and association fibres than HCs and HY2PDs. Motor severity was inversely correlated with FA, but positively correlated with MD and RD in PD patients. Connectometry analysis also revealed increased WM density in the aforementioned tracts in PD patients, compared with HCs. Our study reveals WM enhancement, suggesting neural compensations in early PD. Longitudinal follow-up studies are warranted to identify the trajectory of WM changes alongside the progression of PD.
authors.affiliation: Department of Research, National Neuroscience Institute, Singapore.
authors.forename: Ming-Ching
authors.initials: MC
authors.lastname: Wen
authors.affiliation: Department of Research, National Neuroscience Institute, Singapore.
authors.forename: Hannah S E
authors.initials: HS
authors.lastname: Heng
authors.affiliation: Department of Research, National Neuroscience Institute, Singapore.
authors.forename: Samuel Y E
authors.initials: SY
authors.lastname: Ng
authors.affiliation: Department of Neurology, National Neuroscience Institute, Singapore.|Duke-NUS Graduate Medical School, Singapore.
authors.forename: Louis C S
authors.initials: LC
authors.lastname: Tan
authors.affiliation: Department of Diagnostic Radiology, Singapore General Hospital, Singapore.
authors.forename: Ling Ling
authors.initials: LL
authors.lastname: Chan
authors.affiliation: Department of Research, National Neuroscience Institute, Singapore.|Department of Neurology, National Neuroscience Institute, Singapore.|Duke-NUS Graduate Medical School, Singapore.
authors.forename: Eng King
authors.initials: EK
authors.lastname: Tan
mesh_terms: D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000473:pathology*; D066127:White Matter / Q000000981:diagnostic imaging / Q000473:pathology*