Progression of Regional Microstructural Degeneration in Parkinson's Disease: A Multicenter Diffusion Tensor Imaging...

Area of Science:

• Neuroimaging
• Neurology
• Biomarkers

Background:

• Parkinson's disease (PD) is a progressive neurodegenerative disorder.
• Identifying reliable markers for PD progression is crucial for effective management.
• Diffusion tensor imaging (DTI) offers insights into white matter microstructure.

Purpose of the Study:

• To evaluate the utility of DTI in quantifying microstructural progression in de-novo PD patients.
• To assess regional DTI changes and their correlation with clinical and biomarker data.

Main Methods:

• Longitudinal DTI scans from 122 de-novo PD patients and 50 controls (Parkinson's Progression Markers Initiative).
• Automated image processing for intra- and inter-subject registration.
• Estimation of annualized DTI variations (FA, rD, aD) in 118 regions of interest.

Main Results:

• PD patients showed accelerated FA reduction and diffusivity increases compared to controls, predominantly in the substantia nigra, midbrain, and thalamus.
• Substantia nigra showed highest FA reduction (3.6%/year); thalamus showed highest diffusivity increase (rD: 8.0%/year).
• DTI changes correlated with dopaminergic deficits, CSF biomarkers (α-synuclein, tau), and cognitive decline in PD.

Conclusions:

• Regional microstructural degeneration, as measured by DTI, represents potential markers for Parkinson's disease progression.
• DTI metrics can track disease-related changes in specific brain regions.
• DTI may aid in monitoring PD progression and treatment response.