Neuropathy, A General Guide

As is usual on this blog, every now and then, a new post will appear which gives a different general picture of what neuropathy is and how it's normally treated. These posts are for newcomers to the blog, or people who have just been diagnosed with the condition, or people who want to understand exactly what's happening to them. People who have had neuropathy for a long time, will probably be aware of most of the facts shown here but it doesn't do any harm to refresh your knowledge now and again. I always learn something new whenever I read one of these articles because every source comes at it from a slightly different angle. Today's post is from weillcornell.org (see link below) a medical college and is an excellent introduction to the disease.

Neuropathy

The nervous system is made up of two parts. The core is your central nervous system — your brain and spinal cord. The rest of your nervous system, branching off from your spinal cord to the rest of your body, is your peripheral nervous system.

Neuropathy is a disorder that prevents nerves from functioning properly. It can cause paralysis if a nerve is completely lacerated, although total paralysis is rare in people with neuropathy. Rather, the disease causes varying degrees of weakness, depending on the type and severity of the neuropathy.

• Peripheral neuropathy involves damage to the peripheral nerves that transmit pain and temperature sensations, and can prevent people from sensing that they have been injured from a cut or that a wound is becoming infected. Pain receptors in the skin can also become over-sensitized, so that people may feel severe pain from stimuli that are normally painless (for example, some may experience pain from bed sheets draped lightly over the body).
• Autonomic neuropathy is damage to the nerves that regulate the part of your nervous system that you can't control — the nerves that regulate your heart rate, blood pressure, perspiration and digestion, among other functions. Your nerves transmit messages between your brain and your muscles, blood vessels, skin and internal organs. Damage to your autonomic nerves results in faulty communication between your brain and the parts of your body that your autonomic nervous system serves. People may not detect pains that warn of impending heart attack or other acute conditions. Autonomic nerve dysfunction can become life threatening and may require emergency medical care in cases when breathing becomes impaired or when the heart begins beating irregularly.

Causes

Peripheral neuropathy can result from

• diabetes
• nerve compression or entrapment
• trauma
• penetrating injuries
• fracture or dislocated bones
• tumor
• intraneural hemorrhage
• exposure to cold or radiation
• rarely, certain medicines or toxic substances
• vascular or collagen disorders such as atherosclerosis, lupus, scleroderma, sarcoidosis, and rheumatoid arthritis.

In some cases, neuropathy is caused by heredity, vitamin deficiency, infection, and kidney disease.Symptoms

Peripheral neuropathy produces symptoms such as weakness, muscle cramps, twitching, pain, numbness, burning, and tingling (often in the feet and hands). Symptoms are related to the type of affected nerve and may be seen over a period of days, weeks, or years. Neuropathic pain is difficult to control and can seriously affect emotional well-being and overall quality of life. Neuropathic pain is often worse at night, seriously disrupting sleep and adding to the emotional burden of sensory nerve damage.

• Motor nerve damage causes muscle weakness, and symptoms may include painful cramps and muscle twitching, muscle loss, bone degeneration, and changes in the skin, hair, and nails.
• Sensory nerve damage may result in a general sense of numbness, especially in the hands and feet. People may feel as if they are wearing gloves and stockings even when they are not. Damage to these fibers may cause people to become insensitive to injury from a cut or that a wound is becoming infected. Others may not detect pains that warn of impending heart attack or other acute conditions. Pain receptors in the skin can also become oversensitized, so that people may feel severe pain from stimuli that are normally painless (for example, some may experience pain from bed sheets draped lightly over the body).

Symptoms of autonomic nerve damage are diverse and depend upon which organs or glands are affected. Common symptoms include:

• An inability to sweat normally, which may lead to heat intolerance
• A loss of bladder control, which may cause infection or incontinence and
• An inability to control muscles that expand or contract blood vessels to maintain safe blood pressure levels. A loss of control over blood pressure can cause dizziness, lightheadedness, or even fainting when a person moves suddenly from a seated to a standing position (a condition known as postural or orthostatic hypotension).
• Gastrointestinal symptoms frequently accompany autonomic neuropathy. Nerves controlling intestinal muscle contractions often malfunction, leading to diarrhea, constipation, or incontinence. Many people also have problems eating or swallowing if certain autonomic nerves are affected.

Diagnosis

Neuropathy can be a difficult condition to diagnose. To begin, your doctor will take a full medical history and perform a physical and neurologic exam that may include checking your

• tendon reflexes
• muscle strength and tone
• ability to feel certain sensations, and
• posture and coordination

Your doctor also may request one or more of the following:

• blood tests to check your level of vitamin B-12
• a urinalysis
• thyroid function tests and, often
• electromyography (EMG) — a test that measures the electrical discharges produced in your muscles
• a nerve conduction study, which measures how quickly your nerves carry electrical signals. A nerve conduction study is often used to diagnose carpal tunnel syndrome and other peripheral nerve disorders
• Your doctor may recommend a nerve biopsy, a procedure in which a small portion of a nerve is removed and examined for abnormalities. But even a nerve biopsy may not always reveal what's damaging your nerves

Treatment

Neuropathy does not usually clear up unless the problem causing neuropathy is treated or removed. Controlling a chronic condition may not eliminate your neuropathy, but it can play a key role in managing it.
Depending on the cause, neuropathy may be relieved by medications, vitamin supplements, physical or occupational therapy, splinting, or surgery. Here's what your doctor may recommend for treating various underlying conditions:

• Diabetes. If you have diabetes, you and your doctor can work together to keep your blood sugar level as close to normal as possible. Maintaining normal blood sugar levels helps protect your nerves.
• Vitamin deficiency. If your neuropathy is the result of a vitamin deficiency, your doctor may recommend injections of vitamin B-12 daily for a few days, then once a month. If you have pernicious anemia, you'll need regular injections for the rest of your life, and possibly additional vitamin supplements.
• Autoimmune disorder. If caused by an inflammatory or autoimmune process, your neuropathy treatment will be aimed at modulating your immune response.
• Nerve pressure. Treatment will likely focus on adding ergonomic chairs, desks or keyboards to your home or office, changing the way you hold tools or instruments, or taking a break from certain hobbies or sports. Only in extreme cases of nerve compression will you need surgery to correct the problem.
• Toxic substances or medications. If toxins or medications are responsible for the neuropathy, it's critical that you avoid further exposure to the toxin.

Medications

Medications can ease pain symptoms, but most have side effects, especially if you take them for long periods of time. If you take pain medication regularly, including over-the-counter products, discuss the benefits and side effects with your doctor. Medications that may help provide pain relief for neuropathy include:

• Pain relievers
• Anti-seizure medications
• Lidocaine patch
• Tricyclic antidepressants
• Other medications, including opioid analgesics; mexiletine (Mexitil), or the topical ointment capsaicin may help ease the pain of diabetic neuropathy

Drug-free therapies

Several complementary or alternative therapies and techniques may also help with pain relief. They include:

• Hypnosis
• Acupuncture
• Biofeedback
• Relaxation techniques, including deep-breathing exercises, visualization, yoga and meditation
• Transcutaneous electrical nerve stimulation (TENS), a safe, painless therapy using tiny electrical impulses to help block pain signals

Research

Research aimed at finding more effective treatments for peripheral neuropathy is ongoing. For example, researchers are looking at developing nerve growth factors to reproduce the chemicals that signal your body to repair small nerve fibers. Other scientists are studying the use of the antioxidant alpha lipoic acid (thioctic acid) to treat diabetic neuropathy. Unfortunately, no medications can repair nerve damage yet, but the body can regenerate nerves if the offending substance is removed.

http://www.weillcornell.org/health/neuropathy.html