Fact Sheet: Peripheral Neuropathy

Peripheral neuropathy is a condition caused by damage to the nerves in the peripheral nervous system. The peripheral nervous system includes nerves that run from the brain and spinal cord to the rest of the body. Many of these nerves are involved with sensation and feeling things such as pain, temperature and touch. Up to one-third of people with HIV may get some symptoms of peripheral neuropathy. Peripheral neuropathy is usually felt at first as tingling and numbness in the hands and feet. Symptoms can be described as burning, shooting pain, throbbing, aching and "feels like frostbite" or "walking n a bed of coals".

Peripheral neuropathy can sometimes be caused by HIV but is most commonly a side effect of drugs. Sometimes neuropathy can be caused by vitamin deficiencies or diabetes. Diagnosis of peripheral neuropathy is done by a physical exam. Tests of vitamin B12 levels, thyroid function and glucose levels are also used to check for vitamin deficiencies or diabetes. If peripheral neuropathy is caused by a drug, the symptoms usually get better once the drug is stopped, although it can take 6 to 8 weeks and the pain can actually get worse for a while.

Drugs that can cause peripheral neuropathy: Some drugs that people with HIV taken can cause peripheral neuropathy. Not everyone taking these drugs will get peripheral neuropathy, but it's something to watch out for. The risk of getting peripheral neuropathy can sometimes increase when the drugs listed here are taken together. The anti-HIV drugs ddI (Videx), ddC (Hivid), and d4T (Zerit) are the most common causes of drug-related neuropathy. Other potential causes are INH (isoniazid), ethambutol (Myambutol), vincristine, metrodinazole (Flagyl), dapsone. Drinking alcohol increase the risk of neuropathy. Taking too much vitamin B6 can also cause neuropathy. There have been reports of neuropathy associated with protease inhibitor indinavir (Crixivan).

Treatments: There is no proven treatment for peripheral neuropathy. Recent studies have reported good results with an anti-seizure drug called Neurontin (gapapentin). An antidepressant called Elavil was once a commonly prescribed treatment, but recent studies have found little benefit from this drug. Other options that are sometimes treid are a heart drug called mexiltine and anti-seizure medications called Tegretol and Dilantin. Using medications this way is called off-label use, because the drugs were not studied or approved as treatments for peripheral neuropathy. Insurance companies will sometimes not pay for off-label use. Medicaid is required to provide coverage by law, as long as there is medical evidence that the off-label use is effective. When symptoms are moderate to severe, use of steroids such as prednisone for a short period may be helpful. With all these treatments, it may take several weeks to relieve symptoms.

Nutrients and peripheral neuropathy: While nutrients and vitamin supplements haven't been studied the way other drugs have been as treatments for peripheral neuropathy, there are something's you can do yourself that may7 help with symptoms. Many of the B vitamins have been found to help with symptoms of peripheral neuropathy, although high levels of B6 may worsen symptoms. The ones that are helpful are B1, B12 and folate. Try taking a multivitamin with vitamin E in it, and B complex to help symptoms of peripheral neuropathy. Make sure the B complex, sometimes called a vitamin B stress complex, has folate in it. Vitamin B12 can also be given by shots into a muscle every couple of weeks, and this probably gets more vitamin B12 into the body than vitamin pills. Drinking alcohol can block how your body uses folate and vitamin B12.

Other supplements that have shown some effect on neuropathy include magnesium, alpha-lipoic acid (also known as thioctic acid) and gamma linolenic acid (GLA). One study sued a diet high in a nutrient called inositol, which is found in cantaloupe, peanuts, grapefruit and whole grains. These nutrients have been studied in diabetic neuropathy, which is though to be similar to HIV-related neuropathy.

Studies: A study of a topical cream called Lidoderm is ongoing at Mount Sinai Medical Center in New York. Call the Network for referral. A treatment called nerve growth factor (NGF) was also being studied for treatment of peripheral neuropathy, but these studies have now been stopped. Although some people have reported good results with NGF, the company that makes it (Genetech) has decided to stop any further development of the drug.