For many of us, exercise hurts. We often equate athletics with muscle aches, stomach cramps, sore knees, and tired lungs. But, for those with neuropathic pain, exercise can offer a rare refuge from agonizing discomfort.
Neuropathic pain comes from damaged nerves. It can come from diabetes, stroke, multiple sclerosis, amputation, HIV infection, or sometimes no apparent cause. The disorder involves chronic or episodic pain, and causes individuals to hurt more from stimuli that would barely bother a typical person.
Researchers in Taiwan report today in the journal Anesthesia and Analgesia that they’ve pinpointed some reasons why exercise can help those with neuropathic pain.
The Taiwanese scientists performed their research using rats with sciatic nerve injury. For a few weeks post injury they had some of the rats regularly swim or run on a treadmill. As predicted, the rats who’d excercised showed reduced observable neuropathic pain behaviors.
When the researchers looked at the rats’ levels of inflammation-promoting cytokines in sciatic nerve tissue, the cytokines were significantly reduced in those that had exercised. Such inflammation has been shown to be a major component of neuropathic pain.
The exercising rats also showed increased levels of heat shock protein-27, which could also help lower the amount of inflammation-promoting cytokines in their bodies.
Overall, the rats that exercised showed a 30-50% reduction in abnormal pain responses.
Exercise has long been shown to decrease pain in typical individuals, even just as a means of distraction. But this study shows how exercise can target specific mechanisms of a pain disorder.
By showing the effectiveness of exercise in neuropathic pain treatment, this research offers an alternative to side effect-inducing antidepressant and antiepileptic drug therapies.
Photo: Mike Baird/Flickr
