Structural changes in Parkinson's disease: voxel-based morphometry and diffusion tensor imaging analyses based on...

Area of Science:

• Neuroimaging
• Neurology
• Cardiology

Background:

• Parkinson's disease (PD) is associated with sympathetic nervous system dysfunction.
• ¹²³I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy can quantify cardiac sympathetic denervation in PD.
• The relationship between cardiac sympathetic function and brain microstructural changes in PD is not fully understood.

Purpose of the Study:

• To investigate the association between microstructural brain alterations and ¹²³I-MIBG uptake in Parkinson's disease patients.
• To utilize voxel-based morphometry (VBM) and diffusion tensor imaging (DTI) to analyze brain structure in relation to MIBG scintigraphy results.

Main Methods:

• Retrospective analysis of 24 Parkinson's disease patients undergoing 3T MRI and ¹²³I-MIBG scintigraphy.
• Patients categorized into MIBG-positive (n=12) and MIBG-negative (n=12) groups based on heart/mediastinum (H/M) ratio.
• VBM and DTI applied to detect structural and white matter integrity differences between the two groups.

Main Results:

• Lower H/M ratio correlated with significantly reduced gray matter volume in the right inferior frontal gyrus (p<0.0001).
• Patients with low H/M ratios showed significantly reduced fractional anisotropy in several white matter tracts, including the left anterior thalamic radiation and left uncinate fasciculus (p<0.05).
• These findings suggest a link between cardiac sympathetic denervation and specific brain structural changes in PD.

Conclusions:

• Voxel-based morphometry and diffusion tensor imaging can identify microstructural brain changes in Parkinson's disease.
• These advanced MRI techniques correlate with the degree of ¹²³I-MIBG uptake, reflecting sympathetic dysfunction.
• Advanced MRI methods offer precise detection of gray and white matter damage associated with PD progression.