Approximately 60 percent of HIV+ people will develop problems that involve the nervous system. The nervous system controls thinking, movement, sensations, and feelings.

There are two parts of the nervous system: the brain and the spine (central nervous system) and the peripheral nerves (peripheral nervous system). The peripheral nerves run through the body like webbing, connecting all the parts of the body to the brain and the spine. Any disorder involving the peripheral nervous system is called peripheral neuropathy or PN.

The most common peripheral neuropathy is called distal symmetric polyneuropathy (DSPN). This is what most HIV+ people are talking about when they say they have neuropathy. Most doctors know it as a sock and glove nerve problem, because the areas most affected are where you wear your socks and gloves.

The causes of PN are still unknown. Researchers suspect that either HIV, or drugs that are toxic to the nervous system (neurotoxic drugs), or a combination of both may cause the damage to the peripheral nerves.

PN happens when the communication between the nerves in the feet and/or hands to the brain and spinal cord become damaged. Like frayed wires that can spark or misfire, PN becomes a painful, numb, burning, shooting sensation that many sufferers describe as “holding a lit match to my feet,” or “walking on broken glass.” This chronic pain can lead those who suffer to become isolated, depressed, and even suicidal.

There are certain risk factors for PN:

• Low CD4 cell counts
• Older age (greater than 50)
• Medical conditions (for example, diabetes)
• Alcoholism
• Neurotoxic drugs
• Vitamin B12 deficiency (rarely)

Neurotoxic drugs include many that are used to treat HIV or HIV-related conditions. The most familiar are the HIV drugs commonly called the “d-drugs:”

• d4T (Zerit)
• ddC (Hivid)
• ddI (Videx)

Other neurotoxic drugs include:

• INH (isonizaid)
• Myambutol (ethambutol)
• Flagyl (metronidazole)
• Hydoxyurea

Early signs of PN include:

• Tingling
• Pins and needles
• Numbness
• Feet feeling like they are asleep
• Stumbling when you walk
• Feet throbbing or cramping at night
• Sudden sharp shooting pains

It is these slight or occasional sensations that are often overlooked by both the patient and the doctor. Do not ignore these symptoms or they may get worse. In some cases the pain in the feet becomes so bad that it is difficult to walk or even sleep. If you have any of these symptoms, talk to your doctor right away so that you can receive early diagnosis and treatment. Diagnosing PN can be difficult because the symptoms can vary from person to person, but there are things your doctor can do to check if you have PN.

Your doctor will examine you and ask you questions about your symptoms, work environment, social habits, exposure to any toxins, history of alcoholism, and family history of neurological disease. He or she may order tests and scans to determine the extent and type of nerve damage. A test called a skin biopsy used to be done mostly by researchers, but it may become more common because it can reveal damage in small nerve fibers before permanent damage occurs. Your doctor may also refer you to an HIV-experienced neurologist.

Unfortunately, there are no approved medical treatments to cure PN. For now, the key to treating PN is to remove the cause or control the pain.

Finding what works can be a process of making different choices. If you are on a d-drug, lowering the dose or stopping the drug should be discussed thoroughly with your doctor. If you decide to stop or reduce a drug, it may take six to eight weeks for the PN symptoms to decrease. If the symptoms continue, the PN could be due to HIV.

Relieving the pain can require a combination of drugs and other non-medical therapies. Using Tylenol or Advil for mild symptoms of PN may help. If the pain continues, your doctor may prescribe opioid-based narcotics (Tylenol with codeine) plus additional drugs such as antidepressants (Elavil), or anticonvulsants (Tegretol, Dilantin, Neurontin, Lamictal). If the pain increases and becomes severe, stronger narcotics may be considered.

Other treatments can include:

• Topical lidocaine patch called Lidoderm
• Acupuncture, massage, yoga, hypnosis, and meditation
• A visit to the podiatrist to discuss how to care for your feet and what shoes or socks you should wear
• Over-the-counter-creams, soaking your feet, or simple, easy exercises or stretches

Certain supplements have been used to treat PN including alpha-lipoic acid (thiotic acid), acetyl-carnitine, and evening primrose oil containing gamma linolenic acid. Caution should be taken when considering these supplements. Their effectiveness has not been proven in large studies, although some very small studies have reported benefit in pain relief. They can also be costly and vary in quality between manufacturers. Discuss supplements with your doctor before taking.

While HIV PN and diabetic PN are not the same disease, sometimes the drugs used to treat diabetic PN disease can be helpful for HIV PN. Recently, two new drugs were approved for the treatment of diabetic nerve pain.

• Lyrica – An anticonvulsant that has been shown to provide pain relief in diabetes PN. There is a study currently underway looking at the effectiveness of Lyrica in HIV PN.
• Cymbalta – An antidepressant approved for diabetic nerve pain and depression that affects two naturally-occurring chemicals in the brain. There may be interactions with HIV drugs but that has not been studied.

Fortunately, there is encouraging news about new drugs in development. One such drug is called capsaicin and comes in a patch. Capsaicin is the ‘hot’ chemical produced in chili peppers. In a recent study, one treatment with the capsaicin patch reduced pain for up to three months. A follow up of the study is continuing to examine the long-term effectiveness of the patch. A multinational trial has started to confirm these findings.

Additionally, research is planned for several PN treatments, including erythropoietin and acetyl-carnitine, which may protect nerves from damage. Another approach being studied is the potential benefit of adding self-hypnosis to an existing pain medication regimen.

Finding support and help is critical. Peer organizations or local HIV support groups can offset the sense of helplessness many people who suffer chronic pain feel. Also, seeing a neurologist early for a diagnosis and targeted medications can help maintain a pain level that is manageable.

The easy way to remember the keys to early diagnosis, treatment and management of PN is to think AIMS:

Awareness – Take the time to notice what your body feels like and how you move.

Information - Never stop asking questions, reading, trying new drugs, therapies, or tools.

Medical Team – Choose physicians who are knowledgeable about HIV and neurological problems and listen to you and answer your questions.

Support – Talk about your feelings and the pain. Find a support group for PN. This will allow you to talk to people who understand what you are going through and can share your frustrations and applaud your successes.

1		Highleyman, L. (2002). Peripheral Neuropathy. Bulletin of Experimental Treatments for AIDS: Retrieved July 2003 from http://www.thebody.com/sfaf/winter02/pn.html
2		Venkat K. and Florian P. (2005). Neurological complications of HIV/AIDS. Bulletin of Experimental Treatments for AIDS: Retrieved October 2006 from http://www.thebody.com/sfaf/winter05/neuro.html
3		Gadd, C. (2006). CROI: Capsaicin patch helps relieve neuropathy. Aidsmap: Retrieved October 2006 from http://www.aidsmap.com/en/news/C007D69E-07D3-41E4-8E59-CC14664AF051.asp
4		Polydefkis, M. (2002). Peripheral Neuropathy and HIV. The Hopkins HIV Report: Retrieved July 2003 from http://hopkins-aids.edu/publications/report/july02_4.html