Patterns of diffusion kurtosis changes in Parkinson's disease subtypes

Area of Science:

• Neuroimaging
• Radiology
• Neurology

Background:

• Diffusion kurtosis imaging (DKI) has shown mixed results in evaluating brain microstructure in Parkinson's disease (PD).
• Previous studies lacked clarity in differentiating PD subtypes and cognitive statuses using DKI.

Purpose of the Study:

• To investigate specific kurtosis changes in the brain in Parkinson's disease.
• To assess the effectiveness of diffusion imaging in distinguishing healthy individuals from those with PD and varying cognitive function.

Main Methods:

• Acquired diffusion MRI scans from 92 participants using a 3T scanner.
• Analyzed white matter integrity using tract-based spatial statistics and gray matter in specific brain regions.
• Employed multivariate logistic regression to identify key diffusion parameters for group differentiation.

Main Results:

• Increased kurtosis in the substantia nigra and motor/premotor cortices distinguished cognitively normal PD patients from healthy controls with 81% accuracy.
• Cognitively impaired PD patients showed white matter microstructural changes and decreased cortical kurtosis compared to cognitively normal PD patients.
• Diffusion parameters accurately differentiated between PD phenotypes with 78% accuracy.

Conclusions:

• Elevated gray matter kurtosis in early PD may indicate microstructural alterations due to alpha-synuclein.
• White matter integrity decline is a key feature in cognitively impaired PD.
• Diffusion kurtosis imaging demonstrates significant potential for diagnosing and characterizing Parkinson's disease.