Peripheral Neuropathy

Peripheral neuropathy is the general term that refers to disorders of peripheral nerves. The peripheral nervous system is made up of the nerves that branch out of the spinal cord to different parts of the body.
Peripheral neuropathy is a relatively common neurological disorder that results from damage to the peripheral nerves. It can be caused by a number of diseases of the nerves or be the result of systemic illnesses. Many of the peripheral neuropathy’s have a well established cause such as diabetes, alcoholism, uremia, AIDs, or nutritional deficiencies. Diabetes is, by far, one of the most common causes of peripheral neuropathy. Other less common causes include exposure to cold or radiation, a few medicines, toxic substances, vascular or collagen disorders, systemic lupus erythematosus, scleroderma and rheumatoid arthritis.

Symptoms of peripheral neuropathy:
The peripheral nervous system consists of motor (to help move) nerves and sensory (to help feel) nerves. Either or both sets of nerves can be affected in neuropathy.

If a sensory nerve is damaged, the predominant symptoms are pain, numbness, tingling, burning or a loss of feeling. They often begin gradually. There may be a tingling sensation or numbness that starts in the toes and/or the balls of the feet and spreads upward. Occasionally the skin may become so sensitive that the slightest touch is agonizing. There may also may be a numbness, or a complete lack of feeling in the feet. At times the symptoms may be barely noticeable and at other times, especially at night, they may be almost unbearable. The symptoms may also include a sensation that you’re wearing an invisible glove or sock; a burning or freezing pain; sharp, jabbing or electric pain; and an extreme sensitivity to touch.

If the motor nerves are damaged there may be a weakness or paralysis of the muscles controlled by the affected nerve(s). In the foot their may be a ‘wasting’ of the muscles as they do not work as well as before.

Diabetic peripheral neuropathy:
Diabetic neuropathy deserves special mention as it is the most common type and can lead to serious complications in those with diabetes. Diabetic peripheral neuropathy means damage of nerve fibres in people with diabetes. The process by which the nerves are damaged is not entirely clear but it is probably related to high blood glucose changes that affect the metabolism of nerve cells.

There are three types of diabetic peripheral neuropathy:

  1. Sensory (loose the ability to detect sensations such as heat, cold, pain)
  2. Motor (loss of strength to control movement)
  3. Autonomic (regulate functions such as heart rate and digestion)

Diabetic peripheral neuropathy can result in two types of problems:
there can be a loss of ability to feel pain and other sensations – this puts the foot at risk of being damaged and not knowing about it, and there can be symptoms of pain and burning leading to discomfort (painful neuropathy).

Treatment of peripheral neuropathy:
The treatment for peripheral neuropathy will differ, depending on the cause. For example, if it is caused by diabetes the therapy involves better control of the diabetes. If it is caused by a vitamin deficiency, then supplementation will help. Medications, such as pain relievers and tricyclic antidepressants are often helpful. Generally, the treatment for peripheral neuropathy is unsatisfactory and often only symptomatic relief is available. Some of these include transcutaneous electrical nerve stimulation, acupuncture and biofeedback.

Protection of the foot in peripheral neuropathy:
As a loss of sensation (numbness) is common in peripheral neuropathy, damage to the foot can go undetected and lead to serious complications (especially in those who also have diabetes). It is best to protect the foot with good fitting footwear and the foot should be inspected daily for damage. Particular attention should be paid to corns and calluses, as these may need treatment by a podiatrist.