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Updated: Jul 11, 2025
Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Neurodegenerative Diseases
Published on: July 28, 2013
A fixel-based analysis of white matter reductions early detects Parkinson disease with mild cognitive impairment
Ting-Wei Liao1, Jiun-Jie Wang2, Chih-Chien Tsai3
1Department of Neurology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan, Taiwan.
Background:
White matter (WM) tract alterations are early signs of cognitive impairment in Parkinson disease (PD) patients. Fixel-based analysis (FBA) has advantages over traditional diffusion tensor imaging in managing complex and crossing fibers. We used FBA to measure fiber-specific changes in patients with PD mild cognitive impairment (PD-MCI) and PD normal cognition (PD-NC).
Methods:
Seventy-one patients with PD without dementia were included: 39 PD-MCI and 32 PD-NC. All underwent diffusion-weighted imaging, clinical examinations, and tests to evaluate their cognitive function globally and in five cognitive domains. FBA was used to investigate fiber-tract alterations and compare PD-MCI with PD-NC subjects. Correlations with each cognitive test were analyzed.
Results:
Patients with PD-MCI were significantly older (p = 0.044), had a higher male-to-female ratio (p = 0.006) and total Unified Parkinson's Disease Rating Scale score (p = 0.001). All fixel-based metrics were significantly reduced within the body of the corpus callosum and superior corona radiata in PD-MCI patients (family-wise error-corrected P value < 0.05) compared with PD-NC patients. The cingulum, superior longitudinal fasciculi, and thalamocortical circuit exhibited predominantly fiber-bundle cross-section (FC) changes. In regression analysis, reduced FC values in cerebellar circuits were associated with poor motor function in PD-MCI patients and poor picture-naming ability in PD-NC patients.
Conclusions:
PD-MCI patients have significant WM alterations compared with PD-NC patients. FBA revealed these changes in various bundle tracts, helping us to better understand specific WM changes that are functionally implicated in PD cognitive decline. FBA is potentially useful in detecting early cognitive decline in PD.
Insights
Parkinson disease patients with mild cognitive impairment show significant white matter alterations. Fixel-based analysis (FBA) identified these changes, suggesting its utility in detecting early cognitive decline in Parkinson disease (PD).
Area of Science:
- Neuroimaging
- Neurology
- Cognitive Science
Background:
- White matter (WM) tract alterations are early indicators of cognitive impairment in Parkinson disease (PD).
- Fixel-based analysis (FBA) offers advantages over traditional diffusion tensor imaging for complex fiber analysis.
- This study investigates fiber-specific WM changes in PD patients with mild cognitive impairment (PD-MCI) versus normal cognition (PD-NC).
Purpose of the Study:
- To utilize FBA to quantify and compare fiber-tract alterations between PD-MCI and PD-NC groups.
- To identify specific WM tracts affected in PD-MCI.
- To explore correlations between WM changes and cognitive/motor function.
Main Methods:
- Seventy-one PD patients (39 PD-MCI, 32 PD-NC) underwent diffusion-weighted imaging and cognitive assessments.
- Fixel-based analysis (FBA) was employed to analyze WM microstructure.
- Statistical comparisons and correlation analyses were performed between groups and cognitive tests.
Main Results:
- PD-MCI patients were older and had higher UPRDS scores than PD-NC patients.
- Significant reductions in fixel-based metrics were observed in the corpus callosum and superior corona radiata in PD-MCI.
- Alterations in the cingulum, superior longitudinal fasciculi, and thalamocortical circuits were predominantly cross-section changes; cerebellar circuit changes correlated with motor and naming abilities.
Conclusions:
- PD-MCI patients exhibit significant white matter alterations compared to PD-NC patients.
- FBA effectively reveals fiber-specific WM changes implicated in PD cognitive decline.
- FBA shows potential for early detection of cognitive decline in Parkinson disease.
