Improvement in Touch Sensation after Stroke is Associated with Resting Functional Connectivity Changes

Area of Science:

• Neuroscience
• Rehabilitation Medicine
• Medical Imaging

Background:

• Stroke recovery involves distributed brain networks, but the link between tactile sensation improvement and functional brain connectivity changes remains understudied.
• Understanding these relationships is crucial for developing targeted rehabilitation strategies.

Purpose of the Study:

• To investigate the association between somatosensory function recovery and functional network changes in stroke survivors within the first six months post-stroke.
• To utilize resting-state functional magnetic resonance imaging (fMRI) to analyze these functional network alterations.

Main Methods:

• Ten stroke survivors and ten age-matched healthy controls underwent clinical assessments and resting-state fMRI scans at one and six months post-stroke.
• Functional connectivity was analyzed using fMRI data to assess changes in brain network interactions over time.

Main Results:

• Stroke patients exhibited varied touch impairment severity at one month, with subsequent improvement.
• Significant increases in interhemispheric functional correlations within the somatosensory system, and with visual and frontal areas, were observed at six months compared to one month post-stroke.
• Improved touch discrimination correlated with enhanced connectivity between contralesional secondary somatosensory cortex (SII) and parietal/temporal regions, and between the thalamus and cerebellum.

Conclusions:

• Functional connectivity between somatosensory regions and broader brain networks (vision, attention) evolves in stroke survivors with tactile deficits.
• Connectivity alterations in contralesional SII and thalamus are linked to improved touch sensation at six months post-stroke.
• These identified functional connectivity changes offer potential therapeutic targets for enhancing sensory recovery after stroke.