Distinct functional and macrostructural brain changes in Parkinson's disease and multiple system atrophy.

Area of Science:

• Neuroimaging
• Neurodegenerative Diseases

Background:

• Differentiating Parkinson's disease (PD) and the parkinsonian variant of multiple system atrophy (MSAp) is clinically challenging.
• Task-related functional magnetic resonance imaging (fMRI) and voxel-based morphometry (VBM) offer insights into neurodegenerative processes.

Purpose of the Study:

• To characterize whole-brain fMRI activation patterns during a precision grip task in MSAp patients.
• To compare fMRI and VBM findings between MSAp, PD, and healthy controls.

Main Methods:

• fMRI during a precision grip force task was performed on patients with MSAp, PD, and healthy controls.
• Voxel-based morphometry (VBM) on T1-weighted MRI scans was used to assess brain volume.
• Groups were matched for age, and patient groups had comparable motor symptom duration and severity.

Main Results:

• Both MSAp and PD exhibited reduced fMRI activation in motor control regions compared to controls.
• PD showed more widespread cerebral activation deficits than MSAp.
• MSAp presented significant volume reductions across the basal ganglia, cerebellum, pons, and cerebrum, more extensive than in PD.

Conclusions:

• fMRI reveals abnormal activation in the basal ganglia, cerebellum, and cerebrum in MSAp.
• Extensive, widespread brain volume loss is a key differentiator between MSAp and PD.
• Neuroimaging techniques can aid in distinguishing these neurodegenerative disorders.