Managing Peripheral Neuropathy
by K. Simon Yeung, PharmD, LAc
Modern therapies offer many effective ways to combat cancer. However, they often cause difficult side effects such as nausea and vomiting and hair loss. Another common side effect that may be less often discussed is peripheral neuropathy. Many cancer survivors experience this condition not only during active treatment but also weeks or months following completion of therapy.
What is Peripheral Neuropathy?
Peripheral neuropathy is a nerve disorder caused by damage to the nerves outside of the spinal cord and the brain. Although it may be caused by vitamin deficiency, diabetes, or infections, in people with cancer, peripheral neuropathy can be caused by a tumor that presses on the nerves directly, or as a result of cancer treatment. Surgical procedures, especially those involving dissection of the breast, lung, or the lymph nodes, can sever some nerve fibers. Radiation therapy may also cause nerve injury in the irradiated sites. Certain chemotherapy drugs, such as platinum compounds, taxanes, and vinca alkaloids, may damage nerve tissue. The severity is usually directly related to the dose and duration of the drug used.
Signs and Symptoms
The signs and symptoms can appear in different ways depending on the nerves affected. Some people may experience skin pain, tingling, pricking, and numbness. These sensations usually start at the tips of fingers and toes and gradually progress to the hands and feet. Some people feel strange sensations. For example, an otherwise non-painful stimulus like light touch may be felt as sharp pain, or a minor pain could be greatly magnified. Other people may lose muscle strength, which can make walking, buttoning a shirt, or other daily tasks difficult. Constipation, loss of bladder control, or reduced sexual function also may occur. These problems are self-limiting, but they can become long-term in many cases.
Peripheral neuropathy cannot be totally avoided. However, lifestyle changes, like regular exercise, maintaining a proper diet, and decreasing alcohol consumption may reduce the risk. If discovered at an early stage, it can be properly managed. It is important to be familiar with the signs and symptoms and to discuss them with your doctor as soon as they develop. A simple neurology exam is used for screening, although extensive tests may be necessary for detailed assessment.
Peripheral neuropathy can make daily tasks like buttoning a shirt difficult.
If you are going through chemotherapy, your oncologist can modify or suspend the treatment to minimize damage. Often, symptoms stop after the treatment is discontinued, but if the problem persists, prescription drugs, such as opioids and steroids, can be used. Some drugs that are used to treat depression and seizure can also help to ease the symptoms of peripheral neuropathy. Topical anesthetics or analgesic patches are useful in relieving neuropathic pain and helping protect the skin from irritation. However, none of these approaches can reverse the damage done to the nerves.
Physical and occupational therapies help by improving muscle tone and coordination. But in cases of severe peripheral neuropathy, people may become insensitive to touch and temperature and could then become more prone to falls and burns. Special precautions are required to prevent such injuries.
Increasingly, cancer survivors turn to complementary therapies for symptom relief. Regular exercise and massaging the affected areas can help control symptoms. Research data show that acupuncture can reduce pain and improve nerve function and sensation. Acupuncture is a relatively safe procedure. Many mainstream cancer centers are incorporating acupuncture as a treatment for peripheral neuropathy. Nutritional supplements such as glutamine, glutathione, vitamin Bs, vitamin E, and alpha-lipoic acid also have been tested as treatments for peripheral neuropathy. Early clinical trials indicate that glutamine may reduce the incidence and severity of chemotherapy-induced peripheral neuropathy, but larger studies are needed.
It should be noted that many dietary supplements can interfere with chemotherapy. Therefore, it is important to consult with your physician or pharmacist before using any over-the-counter agents.
For anyone battling cancer, it is not only important to take advantage of the best that modern medicine has to offer but also to learn ways to manage side effects. When dealing with peripheral neuropathy, talk to your doctor so that the problem can be caught early and successfully treated.
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Dr. Simon Yeung is a research pharmacist, acupuncturist, and the manager of the “About Herbs” website in the Integrative Medicine Service at the Memorial Sloan-Kettering Cancer Center in New York.
For more information about the use of herbs and dietary supplements, as well as other complementary and alternative treatments, visit the “About Herbs” website at www.mskcc.org/aboutherbs.
This article was published in Coping® with Cancer magazine, September/October 2008.