Corticomuscular Coherence in Post-Stroke Motor Function and Recovery

Area of Science:

• Neuroscience
• Rehabilitation Medicine
• Biomedical Engineering

Background:

• Simultaneous assessment of cortical and muscle activity aids understanding of motor function post-stroke.
• This study investigated brain-muscle functional connectivity, specifically corticоmuscular coherence (CMC), during the early stages of stroke recovery.

Purpose of the Study:

• To evaluate corticоmuscular coherence (CMC) in individuals with stroke during early recovery.
• To compare CMC between stroke survivors and neurotypical controls.
• To examine the relationship between CMC and motor function recovery.

Main Methods:

• Simultaneous electroencephalography (EEG) and electromyography (EMG) recordings were performed during a grip task in individuals with stroke and controls.
• Beta-band (20-30 Hz) CMC was measured between supplementary motor area (SMA) and first dorsal interosseous (FDI) muscle activity.
• Correlational analyses assessed the association between CMC and motor assessments, with mixed-effects models analyzing differences by group, time, and extremity.

Main Results:

• Individuals with stroke showed reduced beta CMC between SMA and affected FDI compared to controls.
• Lower CMC was observed involving the affected extremity compared to the less affected extremity.
• Higher SMA-FDI CMC at admission was associated with poorer motor recovery.

Conclusions:

• Beta-band SMA-FDI CMC serves as an indicator of neural injury in early stroke recovery, with distinct extremity-specific differences.
• While CMC correlates with motor recovery, its lack of change during hospitalization suggests the need for longer-term studies to understand its recovery trajectory.