Identification of a specific functional network altered in poststroke cognitive impairment

Area of Science:

• Neuroscience
• Neurology
• Medical Imaging

Background:

• Post-stroke cognitive impairment (PSCI) is a common and debilitating consequence of ischemic stroke.
• Identifying reliable biomarkers for PSCI is crucial for early detection and intervention.
• Resting-state functional connectivity (rsFC) offers a non-invasive method to assess brain network alterations.

Purpose of the Study:

• To investigate the association between post-stroke cognitive impairment and specific resting-state functional connectivity markers.
• To identify potential functional network alterations underlying cognitive deficits six months after ischemic stroke.

Main Methods:

• Resting-state functional MRI was used to assess whole-brain connectivity in 56 ischemic stroke patients.
• Graph theory and network-based statistics (NBS) were employed to analyze functional network organization and regional connectivity.
• Voxel-based morphometry was used to assess cortical atrophy.

Main Results:

• Cognitively impaired stroke patients showed no differences in overall network topological organization compared to unimpaired patients.
• NBS revealed significant functional disconnections in a whole-brain network associated with PSCI, particularly between frontal and temporal gyri.
• These altered connections positively correlated with specific cognitive domain scores, while gray matter thickness and infarct topography did not differ between groups.

Conclusions:

• Post-stroke cognitive impairment is associated with specific disruptions in large-scale brain functional networks, rather than global network organization or structural changes.
• These findings highlight the role of functional disconnection in the pathophysiology of PSCI.
• The identified network alterations may serve as potential biomarkers for cognitive deficits following stroke.