Large-scale network dysfunction in α-Synucleinopathy: A meta-analysis of resting-state functional connectivity

Area of Science:

• Neuroscience
• Neuroimaging
• Systems Neuroscience

Background:

• Dysfunction in large-scale brain networks is observed in alpha-Synucleinopathy (α-Syn) disorders like Parkinson's disease.
• A clear, consistent pattern of brain network dysfunction in α-Syn patients has remained elusive.
• This study aims to elucidate network dysfunction patterns in α-Syn through a comprehensive meta-analysis.

Purpose of the Study:

• To systematically investigate and characterize large-scale brain network dysfunction in patients with α-Synucleinopathy (α-Syn).
• To identify consistent patterns of hyperconnectivity and hypoconnectivity across different brain networks in α-Syn patients compared to healthy controls.

Main Methods:

• A meta-analysis of whole-brain seed-based resting-state functional connectivity studies was conducted.
• Studies compared α-Syn patients with healthy controls (HC) and were published before September 1st, 2020.
• Seed-based effect size mapping (Permutation of Subject Images) identified network-level hyper/hypoconnectivity in α-Syn patients.

Main Results:

• Analysis of 136 datasets (3093 α-Syn patients, 3331 HC) revealed imbalanced connectivity in networks involved in motor and executive control.
• α-Syn patients exhibited hypoconnectivity in the default mode and ventral attention networks, impacting cognition and attention.
• Hyperconnectivity was observed between emotion regulation networks, while bottom-up processing networks showed hypoconnectivity.

Conclusions:

• The findings support neurocognitive models linking network dysfunction to motor, cognitive, and psychiatric symptoms in α-Syn disorders.
• This meta-analysis provides a clearer understanding of the brain network alterations characteristic of α-Synucleinopathy.