Network correlates of disease severity in multiple system atrophy

Area of Science:

• Neuroscience
• Medical Imaging
• Biomarker Discovery

Background:

• Multiple system atrophy (MSA) is a common atypical parkinsonian disorder.
• Resting-state metabolic brain imaging reveals abnormal spatial covariance patterns in MSA patients.
• The utility of these patterns as biomarkers depends on their specificity and correlation with clinical disability.

Purpose of the Study:

• To evaluate the specificity of a previously identified MSA-related metabolic pattern (MSARP).
• To assess the relationship between MSARP expression and clinical disability in individual MSA patients.
• To determine if MSARP can serve as a biomarker for MSA.

Main Methods:

• Utilized [(18)F]fluorodeoxyglucose Positron Emission Tomography (PET) in 33 MSA patients, 20 Parkinson disease (PD) patients, and 15 healthy volunteers.
• Calculated MSARP and PD-related pattern (PDRP) expression on a single-case basis for each subject.
• Correlated individual network values with clinical motor ratings and disease duration.

Main Results:

• MSARP values were significantly elevated in MSA patients compared to controls and PD patients (p < 0.001).
• In MSA patients, MSARP expression correlated with motor disability (r = 0.57, p = 0.0008) and disease duration (r = -0.376, p = 0.03).
• MSARP expression did not differ between PD patients and controls (p = 1.0), and motor ratings in PD patients correlated with PDRP, not MSARP.

Conclusions:

• MSA is characterized by elevated expression of a specific metabolic pattern (MSARP).
• The degree of MSARP expression in MSA patients correlates with their clinical motor disability.
• The MSARP shows potential as a valuable biomarker for clinical trials in multiple system atrophy.