Multimodal exercises simultaneously stimulating cortical and brainstem pathways after unilateral corticospinal lesion

Brain Res, 2013 · DOI: 10.1016/j.brainres.2013.07.012 · Published: November 13, 2013

Spinal Cord Injury Neurology Rehabilitation

Simple Explanation

This study investigates how to improve motor control after damage to the corticospinal tract (CST), which is important for skilled movements. The researchers hypothesized that combining exercises that stimulate both the brain's cortex and the brainstem could help strengthen connections in the brain. Mice with CST injuries were trained using different exercise methods: postural exercises for brainstem stimulation, limb-grip exercises for CST stimulation, a combination of both, or no training. The study then assessed the impact of these training regimens on motor skills and brain structure. The multimodal training group (brainstem + CST stimulation) showed a trend toward greater improvements in skilled limb performance compared to the other groups. However, there were no significant anatomical differences observed in the brain structure between the training groups.

Study Duration

4 weeks

Participants

55 PyX mice and 10 sham-lesioned mice

Evidence Level

Not specified

Key Findings

1
Mice in the BS+CST training group showed a trend toward greater improvement in placement errors made by the impaired forelimb than mice in the other groups.
2
Mice in either the BS+CST or CST training groups showed a slight tendency to use the impaired forelimb to a greater extent during the cylinder exploration test
3
Multimodal BS+CST training neither increased corticobulbar fiber density of the lesioned CST rostral to the lesion nor collateral sprouting of the unlesioned CST caudal to the lesion.

Research Summary

The study examined whether multimodal exercise training improves recovery specifically from CST damage in mice with unilateral pyramidotomy (PyX). Behavioral results showed that mice undergoing combined brainstem and CST exercises exhibited a trend toward greater improvement in skilled climbing compared to single-modality exercises. Anatomical analysis revealed no significant differences between training groups in CST sprouting, suggesting that training might modulate the strength of pre-existing corticobulbar synapses.

Practical Implications

Rehabilitation Strategy

Multimodal exercises targeting both cortical and brainstem pathways may be a beneficial approach for physical rehabilitation after corticospinal tract injury.

Synaptic Strength

Further research should focus on electrophysiological assessments to understand how multimodal exercises change synaptic strength between the cortex and spinal cord.

Human Translation

The multimodal approach is being translated to human patients with chronic thoracic SCI to compare its effects against traditional treadmill training.

Study Limitations

1
Mice assigned to the multimodal training group tended to have more severe lesions on post hoc analysis than mice assigned to the other groups.
2
The dose of training in this study may have been too small.
3
Unilateral CST lesion produced a minimal degree of behavioral dysfunction in our cohort

Your Feedback

Was this summary helpful?

Back to Spinal Cord Injury