Abstract

OBJECTIVE
To investigate the white matter (WM) microstructure using diffusion tensor imaging in patients with vascular parkinsonism (VP) and specific fiber tract involvement with respect to clinical severity.
DESIGN
Diffusion measures (fractional anisotropy and mean diffusivity) were calculated from diffusion tensor images of patients with VP and control subjects. We performed global-, voxel-, and tract-based analyses to compare WM microstructural properties between groups.We further correlated findings with Unified Parkinson's Disease Rating Scale scores and modified postural instability gait difficulty (PIGD) scores to identify most relevant tract involvement.
SETTING
Shin-Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan.
PARTICIPANTS
Twelve patients with VP and 12 age-matched healthy controls without VP.
RESULTS
In the VP group, the left thalamus, right frontal subcortical WM, and left anterior limb of the internal capsule had a significantly lower regional fractional anisotropy compared with the control group. The bilateral frontal subcortical WM showed a significantly higher regional mean diffusivity. The diffusion metrics in these regions were significantly correlated with the modified PIGD score part III, and the sum of modified PIGD scores parts II and III. Tract-based analysis showed a group difference in mean fractional anisotropy and mean diffusivity for multiple fiber bundles, but only diffusion measures of fiber tracts from the bilateral frontal lobe that pass through the anterior limb of internal capsule and tracts of the genu of the corpus callosum showed significant correlation with these scores.
CONCLUSIONS
Disruption of the microstructural organization of frontal lobe WM is associated with the severity of VP. Our findings are in accordance with the frontal lobe disconnection hypothesis for gait problems and reinforce the paradigm that the involvement of fibers related to the prefrontal cortex is crucial for the core features of VP.

Links

Publisher Full Text

Authors

Wang HC, Hsu JL, Leemans A

Institution

Department of Neurology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan.

Source

Archives of neurology 69:10 2012 Oct pg 1340-8

MeSH

Aged
Aged, 80 and over
Anisotropy
Brain Mapping
Case-Control Studies
Cerebral Cortex
Corpus Callosum
Diffusion Tensor Imaging
Disability Evaluation
Female
Humans
Image Processing, Computer-Assisted
Magnetic Resonance Imaging
Male
Nerve Fibers, Myelinated
Neurologic Examination
Parkinson Disease
Severity of Illness Index
Taiwan
Vascular Diseases

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

22825428