Another Reason To Exercise: Pain Relief
For those with chronic pain, exercise may be the last thing you feel like doing. However, a new study finds that getting active may actually help alleviate some pain, including that related to nerve damage.
Neuropathic pain, or pain caused by nerve damage, is a complex problem in which the nerve fibers may be damaged, dysfunctional or injured causing symptoms such as shooting and burning pain and tingling and numbness. The impact of nerve fiber injury includes a change in nerve function both at the site of the injury and the areas that surround it. Some common causes of neuropathic pain include diabetes, multiple sclerosis, shingles, chemotherapy treatment and alcoholism.
Physicians in Taiwan, including lead author Yu-Wen Chen PhD of China Medical University, studied the effects of using exercise as a treatment of nerve-related pain in laboratory animals. The researchers induced sciatic nerve injury in rats. This is the nerve formed by nerve roots coming out of the spinal cord into the lower back, going down through the buttock and branching out into the back of the leg and foot. The rats then performed progressive exercise, either swimming or treadmill running, over the course of a few weeks.
The team noted significant reductions in neuropathic pain after exercise, as expressed by a decreased response to temperature and pressure. Although the pain was not completely eliminated, it was reduced by 30 to 50 percent.
The activity also appeared to reduce the expression of inflammation-promoting cytokines in the sciatic nerve tissue, specifically tumor necrosis factor-alpha and interleukin-1-beta. The reduction in inflammation was likely due to the decreased expression of a protein called heat shock protein-27, which is involved in cytokine expression.
Neuropathic pain can be difficult to treat as the burning pain and numbness is not often alleviated by conventional pain medications. Sometimes, antidepressants and antiepileptic drugs can be helpful, but these have significant side effects. The researchers hope that further studies will continue to find benefits for exercise as a non-drug treatment for nerve-related pain.
The Foundation for Peripheral Neuropathy offers tips for exercise in those with nerve-damage pain including aerobic exercise such as walking and swimming and stretching/flexibility exercises. Of course, patients with chronic medical conditions should always check with their physicians first before embarking on a new exercise program.
Yu-Wen Chen, Yung-Tsung Li, Yu Chung Chen, Zong-Ying Li, and Ching-Hsia Hung. Exercise Training Attenuates Neuropathic Pain and Cytokine Expression After Chronic Constriction Injury of Rat Sciatic Nerve. Anesth Analg June 2012 114:1330-1337; published ahead of print March 13, 2012, doi:10.1213/ANE.0b013e31824c4ed4