Disruptions in Structural and Functional Connectivity Relate to Poststroke Fatigue

Area of Science:

• Neuroscience
• Neurology
• Medical Imaging

Background:

• Poststroke fatigue (PSF) is a common and disabling condition following a stroke.
• The exact causes of PSF are not fully understood, and focal lesion characteristics are not consistently predictive.
• Stroke lesions can cause widespread network changes beyond the immediate damaged tissue.

Purpose of the Study:

• To investigate the relationship between structural and functional brain connectivity and poststroke fatigue.
• To determine if disruptions in brain networks are associated with fatigue severity in patients with middle cerebral artery (MCA) stroke.

Main Methods:

• Structural and resting-state functional magnetic resonance imaging (MRI) were used in 12 patients with chronic MCA ischemic stroke.
• Structural MRI measured disconnection of gray matter pathways.
• Functional MRI assessed network functional connectivity.

Main Results:

• Patients exhibited structural disconnection in various cortical and subcortical regions.
• Fatigue severity significantly correlated with structural disconnection in frontal cortex regions (ipsilesional and contralesional).
• The ipsilesional rostral middle frontal cortex showed the most severe fatigue-related structural disconnection and a significant loss in functional connectivity correlating with fatigue.

Conclusions:

• Disruptions in structural and functional connectivity of bihemispheric frontal cortex regions play a role in PSF.
• Connectivity alterations in the ipsilesional rostral middle frontal cortex are centrally implicated in poststroke fatigue.