Prior voluntary wheel running attenuates neuropathic pain

Pain, 2016 · DOI: 10.1097/j.pain.0000000000000607 · Published: September 1, 2016

Neurology Pain Management Rehabilitation

Simple Explanation

This research investigates how exercise, specifically voluntary wheel running, affects neuropathic pain in rats. Neuropathic pain is a type of chronic pain that occurs due to nerve damage. The study found that rats who exercised before a nerve injury were less likely to develop neuropathic pain. Additionally, rats who started exercising after developing neuropathic pain experienced a reduction in their pain levels. These findings suggest that exercise may have a protective effect against neuropathic pain and could be a useful strategy for managing this condition. The researchers also identified several biological mechanisms that may be involved in the pain-reducing effects of exercise.

Study Duration

6 weeks prior to surgery, and up to 9 weeks after surgery

Participants

Adult male Sprague Dawley rats (n = 6 rats/group)

Evidence Level

Level 1: Experimental study

Key Findings

1
Prior voluntary wheel running prevented the full development of CCI-induced neuropathic pain for the duration of the injury.
2
Voluntary wheel running, beginning after CCI, progressively reversed established neuropathic pain.
3
Prior exercise suppressed infiltration of macrophages into the injured sciatic nerve and DRG, with attendant decreases in the potent macrophage chemoattractant CCL2.

Research Summary

The study examined the impact of voluntary wheel running on neuropathic pain in rats subjected to chronic constriction injury (CCI) of the sciatic nerve. Exercise was administered either before or after the nerve injury to assess its preventive and therapeutic effects. The research found that pre-injury exercise attenuated the development of allodynia, reduced neuroimmune signaling in the spinal cord, decreased DRG neuron injury, attenuated macrophage infiltration, and modulated serum cytokine levels. Post-injury exercise also reversed established neuropathic pain. The findings suggest that voluntary exercise may be a useful strategy for preventing and managing neuropathic pain, potentially through mechanisms involving neuroimmune modulation and macrophage activity.

Practical Implications

Preventative measure

Regular exercise before nerve injury can significantly reduce the risk of developing chronic neuropathic pain.

Therapeutic intervention

Exercise can be used as a therapy to reverse existing neuropathic pain, even after it has been established.

Underlying mechanisms

The study highlights the role of neuroimmune signaling and macrophage infiltration in neuropathic pain, suggesting potential targets for future treatments.

Study Limitations

1
Distance travelled did not correlate with allodynia after CCI
2
The direct acute effects of exercise (glucocorticoid release, sympathetic activation, hyperthermia, etc.) can be excluded, as they rapidly resolve after exercise
3
Leukocyte function and polarization shifts temporally and anatomically in response to CCI and voluntary wheel running, further characterization is required to identify the contribution of these cells to the attenuation of neuropathic pain.

Your Feedback

Was this summary helpful?

Back to Neurology