Functional Connectivity in Vascular Cognitive Impairment

Functional connectivity refers to the statistical dependence between distinct brain regions, typically measured during rest or task performance. Vascular cognitive impairment (VCI) encompasses a spectrum of cognitive disorders arising from cerebrovascular pathology, including hypertension, cerebral small vessel disease and stroke. In healthy brains, functional networks such as the default mode, salience and central executive networks are balanced to support memory, attention and executive function. Vascular risk factors can disrupt white matter integrity and cerebral perfusion, leading to alterations in network topology, reduced efficiency of information transfer and decoupling between structural and functional connectivity. Recent advances in resting-state functional magnetic resonance imaging (rs-fMRI) and graph theoretical analysis have illuminated how regional activity abnormalities, network segregation and global integration correlate with cognitive decline. Evidence suggests that early compensatory increases in connectivity may precede network breakdown, while progressive decoupling and diminished modularity underlie executive dysfunction and processing speed deficits. Understanding these alterations has practical implications for early diagnosis, risk stratification and targeted interventions aimed at preserving network resilience in at-risk populations.

Research from Nature Portfolio

A recent study examined individuals with hypertension and potential VCI, applying rs-fMRI metrics including amplitude of low-frequency fluctuations, regional homogeneity and network-based statistics. Hypertensive participants exhibited reduced spontaneous activity in regions implicated in vascular and metabolic processes alongside heightened activity in primary somatosensory and prefrontal cortices. Graph theoretical analysis revealed complex local segregation, impaired global integration and weakened connectivity, particularly in frontal and parietal networks. These findings illustrate the early impact of vascular risk on network architecture and suggest that multifaceted connectivity measures may serve as sensitive biomarkers for VCI progression.

Functional Connectivity in Vascular Cognitive Impairment publication trend

The graph below shows the total number of articles in functional connectivity in vascular cognitive impairment across all publications each year (not limited to Nature Index journals).

Technical terms

Vascular cognitive impairment (VCI): A range of cognitive disorders resulting from cerebrovascular pathology.

Functional connectivity: Statistical relationships between spatially remote brain regions measured by synchronous activity.

Resting-state fMRI (rs-fMRI): A technique for assessing spontaneous brain activity when the subject is not engaged in a specific task.

Amplitude of low-frequency fluctuations (ALFF): A measure of the power of spontaneous neural activity in a low-frequency band.

Structural–functional coupling: The relationship between anatomical connections and functional synchronisation across the brain.

Network segregation: The degree to which specialised processing occurs within densely interconnected clusters or modules.

Network integration: The capacity for efficient communication across disparate brain regions or modules.

References

1. Aberrant brain structural–functional connectivity coupling associated with cognitive dysfunction in different cerebral small vessel disease burdens. CNS Neuroscience & Therapeutics (2024).
2. Network structure-function coupling and neurocognition in cerebral small vessel disease. NeuroImage Clinical (2023).
3. Investigating the effect of hypertension on vascular cognitive impairment by using the resting-state functional connectome. Scientific Reports (2024).