Motor cortex electrical stimulation augments sprouting of the corticospinal tract and promotes recovery of motor function

Frontiers in Integrative Neuroscience, 2014 · DOI: 10.3389/fnint.2014.00051 · Published: June 18, 2014

Simple Explanation

The corticospinal tract (CST) is crucial for voluntary movement. After an injury, spared CST circuits can sprout to partially restore lost function. Electrical stimulation of the spared CST or motor cortex can induce CST axon sprouting, helping to rebuild the damaged CST and improve motor skills. This stimulation-induced sprouting is enhanced when combined with the body's natural response to injury, potentially leading to significant improvements in motor function after paralysis.

Study Duration

10 days stimulation, up to 30 days observation

Participants

Rats with unilateral pyramidotomy

Evidence Level

Review Article

Key Findings

1
Electrical stimulation of the motor cortex or spared CST augments sprouting of CST axons, leading to partial reconstruction of the lost CST.
2
Motor cortex stimulation preferentially drives axon outgrowth to the ipsilateral side of the spinal cord, which is typically denervated and impaired after injury.
3
Motor cortex stimulation after pyramidotomy restores skilled forelimb movement in rats, even after chronic injury.

Research Summary

This review discusses how electrical stimulation of the motor cortex can augment sprouting of the corticospinal tract (CST) and promote recovery of motor function after injury. The authors' research demonstrates that activity-dependent processes, such as electrical stimulation, can be harnessed to enhance CST sprouting and improve motor outcomes in animal models of stroke and spinal cord injury. The review concludes by discussing the potential for translating these findings to human clinical trials, emphasizing the importance of identifying individuals with spared CST axons as candidates for this approach.

Practical Implications

Rehabilitation Strategies

Electrical stimulation can be used as a therapeutic approach to promote CST sprouting and motor recovery in individuals with spinal cord injury or stroke.

Timing of Intervention

Motor cortex stimulation is effective even after chronic injury, suggesting that there may not be a critical period for intervention.

Combination Therapies

Pairing motor cortex stimulation with spinal cord stimulation could be a powerful approach to restoring corticospinal function.

Study Limitations

1
The studies are primarily conducted in animal models, and the findings may not directly translate to humans.
2
The optimal stimulation parameters and the range of motor behaviors that can be improved by motor cortex stimulation in SCI need further investigation.
3
Potential maladaptive effects of CST sprouting, such as increased hyperreflexia or spasticity, need to be carefully evaluated.

Your Feedback

Was this summary helpful?

Back to Neurology