Peripheral neuropathy

What is Peripheral neuropathy?

Nerves are communicators. They carry information to and from every part of the body. Without them, we can't function. If anything upsets or damages this process, messages get mixed up or don't get through at all.

Electrical impulses transmitted along the nerves tell us what we're feeling, tasting, smelling, hearing and seeing. They also instruct our muscles to move. They make sure all the organs of the body keep working, whether we're awake or asleep.

There are two parts to the nervous system:

• Central nervous system (CNS) - the brain and the nerves that make up the spinal cord, which runs through the vertebrae.
• Peripheral nervous system (PNS).

The PNS consists of the sensory-somatic nervous system which carries information about sensations and transmits instructions to carry out actions (such as movements). The autonomic nervous system which controls and regulates bodily function (for example, breathing).

Infection, injury, nutritional deficiency and disorders such as diabetes can cause peripheral neuropathy. Excessive alcohol consumption can also lead to nerve damage. The cause varies according to the specific neuropathy.

Symptoms

When the nerves that stimulate muscles to move (motor nerves) are damaged, it's called motor neuropathy. The muscles become weak and wasted through lack of activity. Damage to the facial nerve - by viral infection or inflammation, for example - can cause facial palsy, with weakness of the muscles on one side of the face.

Damage to the nerves responsible for sensation (sensory nerves) is called sensory neuropathy. Tingling, numbness and pain may be felt in the affected areas. Since the feet and hands are usually affected first, walking and holding objects may become difficult.

The damage gradually spreads from the extremities towards the centre of the body, unless the underlying problem is corrected. Nutritional deficiency, for example a lack of B vitamins, is a common cause of sensory neuropathy.

Breathing, blood pressure, and bladder, bowel and other bodily functions are controlled by another set of nerves known as the autonomic nerves (also part of the peripheral nervous system). Damage to these can result in autonomic neuropathy. Symptoms include urine incontinence, constipation, diarrhoea, dizziness, fainting and impotence. Uncontrolled diabetes is the most common cause of this form.

Treatment and recovery

For treatment to begin, the underlying cause of the neuropathy must be established. Correcting nutritional deficiencies, controlling diabetes and cutting back on alcohol may all improve the symptoms, although any existing nerve damage may be permanent.

Physiotherapy and osteopathy can help to strengthen the muscles and get them functioning properly again.