(See also CIDP; Guillain-Barre Syndrome)
The peripheral nerves connect the brain and spinal cord to the rest of the body. Peripheral neuropathy (damage to the peripheral nerves) is a relatively common neurological disorder that can occur as the result of a wide range of underlying conditions or diseases. Diabetes is perhaps the most common – approximately 50 per cent of diabetics suffer from diabetic neuropathy.
Other conditions that cause peripheral neuropathy include autoimmune diseases such as rheumatoid arthritis; infections such as leprosy or AIDS; pressure on a nerve; certain toxic substances, including alcohol; vitamin deficiency; radiation; trauma (eg bone fractures or penetrative injuries); and tumours of the spinal cord. Inherited neuropathies such as Charcot Marie Tooth disease are also common. However, in many cases, no underlying disorder can be diagnosed.
Symptoms of the disorder vary in severity, according to the number of nerves affected. Symptoms may be limited to a single finger or toe, but generally, the arms or legs are affected, although rarely the whole body may be affected. Weakness and numbness in the affected limb or limbs may be accompanied by abnormal sensations (paresthesia) – that is, tingling, “pins and needles”, burning, pain etc. Frequently the symptoms are worse at night.
The condition is usually categorised according to the number of nerves that are affected:
- mononeuropathy involves a single nerve – for example, carpal tunnel syndrome;
- polyneuropathy occurs less frequently, but involves several peripheral nerves throughout the body.
In many cases, no underlying disorder can be found; however, recognised disorders include Chronic Inflammatory Demyelinating Polyneuropathy (CIDP), Guillain-Barre Syndrome and diabetic neuropathy.
Treatment of peripheral neuropathy depends on whether an underlying condition can be identified. For example, carpal tunnel syndrome may be relieved by the use of a splint, or may require surgery on the wrist. Certain other conditions might also require surgery – eg spinal cord tumours. Diabetic neuropathy generally improves when blood sugar levels are strictly controlled; while neuropathies caused by toxic substances will improve if those substances are avoided deficiency neuropathies may improve following vitamin therapy. The inflammatory neuropathies (GBS and CIDP) may respond to immune therapy.
In cases where no underlying cause can be identified, physical therapy and certain medications (such as anti-epileptic medications or tricyclic anti-depressants) may be used to relieve the symptoms. Pain management techniques, including psychological therapy, may also be required.
The prognosis for patients suffering from peripheral neuropathy depends to a large extent on whether an underlying cause can be identified and treated. While some patients fully recover, others may develop a chronic condition requiring ongoing therapy and support.
Further Information and Support
National Institute of Neurological Disorders and Stroke - USA
The Neuropathy Association - USA
Neuropathy Trust - UK
The Inflammatory Neuropathy Support Group of Victoria Inc
Read More at Virtual Medical Centre
Reviewed by Professor John Pollard, Institute of Neuroscience, Royal Prince Alfred Hospital, Camperdown, Sydney, Australia