Increased Brain Sensorimotor Network Activation after Incomplete Spinal Cord Injury

Area of Science:

• Neuroscience
• Rehabilitation Medicine
• Spinal Cord Injury Research

Background:

• Complete spinal cord injury (SCI) significantly reduces brain activation during attempted limb movement.
• Brain activation patterns during attempted movement in incomplete SCI, a more common injury type, remain largely unknown.
• Understanding these patterns is crucial as incomplete SCI often preserves partial voluntary motor function.

Purpose of the Study:

• To assess brain activation during voluntary ankle movement in individuals with incomplete SCI.
• To compare brain activation patterns between incomplete SCI patients and healthy controls.
• To investigate the relationship between brain activation, locomotor function, and time since injury in incomplete SCI.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to measure brain activity.
• Participants (20 incomplete SCI, 15 healthy controls) performed 0.3-Hz right ankle dorsiflexion during fMRI scans.
• Linear regression analysis correlated brain activation with clinical variables like locomotor function and time post-SCI.

Main Results:

• Both groups showed bilateral activation of sensorimotor areas during ankle movement.
• Individuals with incomplete SCI exhibited significantly greater activation in right hemisphere motor and sensory areas (p < 0.001).
• Poorer locomotor function correlated with increased activation in right pre- and post-central gyri; longer time post-SCI correlated with increased activation in left post-central gyrus and supplementary motor area.

Conclusions:

• Brain adaptations following incomplete SCI differ significantly from those after complete SCI.
• These adaptations are linked to the individual's functional status and evolve over time.
• Findings suggest potential biomarkers for understanding and developing treatments for incomplete SCI.