While the specific causes of neuropathy are not fully understood, medical professionals and researchers agree the most effective treatment for neuropathy is the stabilization of blood glucose levels.
This is strongly supported by the results of the Diabetes Control and Complications Trial (DCCT) which reported a 60 percent reduction in the risk of development and progression of neuropathy with tightly controlled blood glucose levels.
Hyperglycemia (high blood sugar) can worsen neuropathy in several ways. Hyperglycemia is known to cause excess blood glucose to bond to proteins in the body. This can lead to direct damage to proteins in the nerves, as well as narrowing of the arteries which, in turn, diminishes blood flow and oxygen delivery, causing pain and tissue death. Elevated blood glucose levels have been demonstrated to create a loss of magnesium in the body, contributing to vascular constriction, impaired blood flow and insulin resistance. Finally, studies of rats that receive beta cell implants and humans who receive pancreas transplants indicate that normalization of glycemic levels clearly halts the progression of neuropathy.
In the past, concern was raised over instructing patients with neuropathy to maintain normal blood sugar levels because it was feared that symptoms of neuropathy might prevent the early detection of hypoglycemia. However, the British Medical Journal (October 1990) reported that hypoglycemic unawareness is not caused by neuropathy. Instead, hypoglycemic unawareness is due to the effects of prolonged hypoglycemia on the hypothalamus, resulting in dysfunction of counter-regulatory hormones that monitor glucose concentration in the blood. The results of this study indicate that neuropathy is not a sufficient reason to advise patients against maintaining normal blood glucose levels.
Alan Marcus, MD, says that two of the most effective treatments include normalizing cholesterol and magnesium levels in the body. Because adequate blood flow and oxygen delivery is important for maintaining healthy nerve tissue, normalizing cholesterol levels to help keep the circulatory system free of obstruction is extremely important.
According to Dr. Arshag Mooradian, co-author of a comprehensive study on diabetes and micronutrients, magnesium plays an important role in glucose metabolism. Further, magnesium deficiency is clearly linked to both diabetes and arteriosclerosis. Dr. Samuel Malayan of the University of California in Los Angeles, found an association between low magnesium blood levels with hypertension in patients with type 2 diabetes.
Given the connection between magnesium deficiency, diabetes, and hypertension, magnesium supplements are often recommended for the treatment and prevention of neuropathy. A blood test is recommended to determine if a patient has a magnesium difficency. (It should be noted, however, that magnesium is not recommended for patients with kidney failure.)
Other vitamin and mineral supplements may also prove helpful. These include vitamin B, myo-inositol, vitamin E, and other antioxidants. Vitamin B deficiency is known to be a cause of neuropathy, and may aggravate the condition once it has begun.
Myo-inositol is a B vitamin complex, and myo-inositol deficiency has been connected to diabetes in animal studies (Clinical Diabetes, July-August 1991). Aaron Vinik, MD, PhD recommends brewer’s yeast as a rich source of myo-inositol that can be safely taken in doses up to 3,000 mg daily.
Vitamin E improves circulation and oxygen utilization, helping to repair any damage. Dr. M.G. Traber discovered that patients with neuropathy had significantly less vitamin E in their tissues than people with other types of neurological disorders (The New England Journal of Medicine, 1987). Dr. Marcus recommends 400 IUs of vitamin E daily in the treatment of neuropathy.
Both vitamin E and gamma linoleic acid are antioxidants. Antioxidants work by neutralizing harmful “free radicals” (activated oxygen atoms) which have been found to damage cells and impair the immune system. A study of the effect of gamma linoleic acid on diabetic neuropathy suggests that supplements are beneficial to nerve function (Lancet, December 1991). A number of readers have reported benefits from gamma linoleic acid, preferably in the form of borage oil capsules.
Always remember that recommendations about taking B or other vitamins should always be made on a case-by-case basis by a qualified medical professional.
Other recommendations for improving the health of the nervous and circulatory systems include adequate exercise, eliminating alcohol and tobacco use and massage.
Using Drugs for Treatment
There are several drugs available for treating the pain of neuropathy. These include antidepressants and anti-convulsants, as well as capsaicin, a topical cream derived from chili peppers. The optimal drug therapy depends upon proper diagnosis.
The drugs most often prescribed for neuropathic pain are desipramine (Norpramin), amitriptyline (Elavil), and fluoxetine (Prozac.) Desipramine, amitriptyline and fluoxetine are antidepressants which stabilize nerve transmission in the body. In a study by the National Institutes of Health, desipramine and amitriptyline were found to reduce pain for both depressed and non-depressed patients with neuropathy, while fluoxetine (Prozac) only helped depressed patients (The New England Journal of Medicine, May 1992) .
Anti-convulsant drugs, such as carbamazepine, may also be useful in treating neuropathic pain when it manifests as an electric type of pain that resembles epilepsy (The Western Journal of Medicine, November 1992). But while they are often effective for pain relief, many people are unable to tolerate the side effects of these drugs, which may include insomnia, nausea and vomiting, cramping, sudden low blood pressure, dry mouth, blurred vision, and urinary retention (Nutrition Health Review, Winter 1992).
For superficial pain, there have been positive results among patients using capsaicin. Capsaicin, derived from the most potent part of the chili pepper, is used in the form of a topical cream (such as Zostrix-HP) containing 0.075 percent concentration of capsaicin, and needs to be applied four to five times daily. In one study, 25 percent of the 219 patients with neuropathy reported complete relief from pain after eight weeks, while another 50 percent reported significant pain relief.
Capsaicin is thought to work either by depleting “substance P,” a neurotransmitter which is fundamental to the body’s pain mechanism, or by acting as a counter-irritant, causing an initial increase and then decrease of pain by over-stimulating certain nerves. This may explain why some individuals experience an initial increase in pain with capsaicin similar to the effect in the mouth of eating a very spicy meal. While this usually fades after a week or two, it appears to deter some people from continuing their treatment. (Diabetes Forecast, June 1992).
Both these studies, as well as reports from DIABETES HEALTH readers, point to clear benefits from the use of capsaicin. However, the use of capsaicin requires care and caution. Special care must be taken when applying the cream to prevent irritation to other parts of the body. Users should wear gloves and apply only a thin layer of the cream which, if applied too thick, may dry and chip off, creating a powder that can irritate the mucus membranes of the eyes, nose, mouth and lungs.
Other Ways to Relieve the Pain
Another experimental substance for pain relief are aldose reductase inhibitors (ARIs) which are thought to work by normalizing the nerve content of sorbitol and fructose in people with diabetes. While early clinical trials on the ARIs tolrestat and sorbinil looked promising, further long-term studies are necessary to fully determine both their effectiveness and the extent of their toxicity.
Finally, Dr. Vinik reports that short-term insulin infusion has been found to ease the pain of neuropathy. The infusion is administered by intravenous drip for 48 to 78 hours, using 0.8-1.0 units of insulin per hour. This treatment was discovered accidentally, and while its effectiveness is not understood, it is clearly not related to blood glucose stabilization.
For muscle pain, the most effective form of treatment appears to be stretching exercises. Many patients show significant improvement without the use of muscle relaxants or anti-inflammatory drugs.
Before trying new treatments for neuropathy, consult your doctor. Not all remedies are recommended for all people.