Altered Spinal Cord Functional Connectivity Associated with Parkinson's Disease Progression

Area of Science:

• Neuroscience
• Medical Imaging
• Neurology

Background:

• Traditionally, Parkinson's disease (PD) is recognized for brain pathology (α-synucleinopathy).
• Emerging evidence suggests the spinal cord may also be affected in PD, based on postmortem studies and animal models.

Purpose of the Study:

• To investigate spinal cord functional organization in PD patients using functional magnetic resonance imaging (fMRI).
• To characterize spinal cord functional connectivity (FC) changes in relation to PD motor symptom severity.

Main Methods:

• Resting-state spinal fMRI was conducted on 70 PD patients (categorized by motor severity) and 24 healthy controls.
• Independent component analysis (ICA) and seed-based approaches were employed to analyze spinal FC.
• Patients were grouped into PDlow, PDmed, and PDadv based on motor symptom severity.

Main Results:

• ICA identified reproducible ventral and dorsal spinal cord components along the rostro-caudal axis.
• A significant decrease in spinal FC was observed in PD patients compared to controls.
• Reduced intersegmental correlation in PD negatively correlated with upper-limb motor scores (UPDRS), particularly in cervical segments C4-C5.

Conclusions:

• This study presents the first evidence of altered spinal cord FC in Parkinson's disease.
• Spinal cord fMRI is a promising tool for in vivo characterization of spinal circuits in neurological diseases.
• Findings open new diagnostic and therapeutic strategies for PD, highlighting the spinal cord's role.