Putaminal Diffusivity Correlates With Disease Progression in Parkinson's Disease: Prospective 6-Year Study

Area of Science:

• Neuroimaging
• Neurodegenerative Diseases
• Biomarker Development

Background:

• Parkinson's disease (PD) is a common neurodegenerative disorder with unclear long-term clinical utility of diffusion tensor imaging (DTI).
• Longitudinal studies are crucial for understanding disease progression and identifying reliable biomarkers.

Purpose of the Study:

• To prospectively evaluate the long-term changes in brain diffusion parameters using DTI in Parkinson's disease patients.
• To assess the correlation between DTI metrics and motor symptom progression in PD.

Main Methods:

• A cohort of 46 PD patients underwent brain DTI at baseline and 6 years later using a 1.5 Tesla scanner.
• Regions-of-interest (ROI) analysis was performed to extract mean diffusivity (MD) and fractional anisotropy (FA) from various brain regions.
• Linear regression analysis correlated DTI parameters with the United PD Rating Scale (UPDRS) scores.

Main Results:

• Mean diffusivity (MD) significantly increased in all brain regions over the 6-year period (P < 0.0001).
• Fractional anisotropy (FA) showed regional variations, increasing in the substantia nigra and posterior putamen, but decreasing in the frontal white matter (P < 0.0001).
• Increased MD in the anterior putamen was significantly associated with motor symptom progression (UPDRS) (P = 0.0003).

Conclusions:

• Serial DTI reveals widespread diffusivity increases and regional microstructural changes in the brain over 6 years in PD patients.
• Longitudinal DTI data, particularly in the anterior putamen, may serve as an objective in vivo biomarker for motor progression in Parkinson's disease.
• DTI shows potential for long-term clinical utility in monitoring PD progression.