Alterations in static and dynamic functional network connectivity in subcortical vascular cognitive impairment

Area of Science:

• Neuroscience
• Cognitive Science
• Medical Imaging

Background:

• Subcortical vascular cognitive impairment (SVCI) is characterized by cognitive deficits.
• Understanding the neurobiological underpinnings of SVCI, particularly alterations in brain connectivity, is crucial for diagnosis and treatment.
• Both static (sFNC) and dynamic (dFNC) functional network connectivity may play roles in SVCI pathophysiology.

Purpose of the Study:

• To investigate the neurobiological mechanisms of altered static and dynamic functional network connectivity in subcortical vascular cognitive impairment (SVCI).
• To explore the relationship between functional connectivity alterations and cognitive function in SVCI patients.
• To characterize the dynamic changes in brain functional activity states and their temporal properties in SVCI.

Main Methods:

• Recruited 80 SVCI patients and 83 healthy controls.
• Utilized resting-state functional MRI (fMRI) data to extract static (sFNC) and dynamic (dFNC) functional network components via independent component analysis.
• Applied sliding time window techniques and cluster analysis to examine dFNC states and temporal properties, followed by t-tests and Spearman correlation analyses.

Main Results:

• SVCI patients exhibited significantly decreased sensorimotor and lateral visual network interactions (sFNC), negatively correlated with executive function.
• Four distinct functional connection states were identified in dFNC, reflecting varying degrees of connectivity.
• dFNC temporal properties (fractional occupancy, mean dwell time) were correlated with cognitive function, indicating impaired adaptive capacity in SVCI.

Conclusions:

• SVCI is associated with significant impairments in both static and dynamic functional network connectivity, contributing to cognitive decline.
• Dynamic connectivity patterns reveal a progression from disruption to diminished compensatory responses in SVCI.
• Functional connectivity dynamics serve as an indicator of the brain's adaptive capacity in the context of cognitive impairment.