Peripheral neuropathy

What is Peripheral neuropathy?

Peripheral neuropathy refers to disease, inflammation, or damage to the peripheral nerves. Peripheral nerves are those that connect the central nervous system (brain and spinal cord) to the sense organs, muscles, glands, and internal organs.

Most neuropathies are caused by damage or irritation to the nerve cell axons (conducting fibers that make up nerves) or to their myelin sheaths (a fatty insulating substance that protects the nerve). Nerve axons may suffer a thinning, patchy, or complete loss of their myelin sheath resulting in slowed or complete block of electrical impulses. This degenerative change in one or more nerves can be the result of an injury, dietary deficiency, metabolic upset, poisoning, inflammation from a viral infection, autoimmune disorder (condition in which the immune system mistakenly reacts against the body's own tissues), or a group of inherited diseases.

Neuropathies are classified according to the site, extent, and distribution of damage.

• A distal neuropathy starts with damage to the end of a nerve farthest from the brain or spinal cord.
• Asymmetrical neuropathy affects nerves at the same locations on each side of the body.
• Mononeuropathy (or mononeuritis) indicates damage to a single nerve, while polyneuropathy (or polyneuritis) indicates damage to several nerves.

Neuropathies can also be described according to their underlying cause such as diabetic neuropathy or alcohol neuropathy.

How is it diagnosed?

Physical exam: There is characteristic weakness and wasting in related areas of the body with a loss of tendon reflexes. When autonomic fibers degenerate, organs of the body may be affected. The skin may be sweaty or dry, hot or cold, pale or flushed, or lesions may erupt.

Tests: Electromyography and nerve conduction tests record electrical activity in the muscles to determine the extent of the damage. Cause of the neuropathy may be determined through blood tests, x-rays, and nerve or muscle biopsy (small amounts of tissue removed for microscopic analysis).

How is Peripheral neuropathy treated?

Treatment is directed toward the underlying cause, primary disease, dietary deficiency, toxic exposure, or mechanical damage to the nerves and limbs. Once the causative factor has been identified and eliminated, the body's natural reparative processes can begin. In addition, physical therapy is important to keep joints loose and muscles stretched.

Medications

Information	Brand	Generic	Label	Rating
	Elavil	Amitriptyline
	Lioresal	Baclofen

Pamelor (Nortriptyline), Tegretol (Carbamazepine), Cymbalta (Duloxetine), Lyrica (Pregabalin), Dilantin (Phenytoin), Ultram (Tramadol)

Activity

• If peripheral neuropathy is interfering with normal activities, physical therapy may help.
• If you have difficulty maintaining balance, walk with a cane or other support.
• Install rails next to the bathtub.

Diet

No special diet. Vitamin and mineral supplements probably will be necessary. Pyridoxine (vitamin B-6) may help.

What might complicate it?

If the cell bodies of the damaged nerves have been destroyed, functional loss (sensory loss or muscle weakness) may become permanent.

Predicted outcome

If damaged nerve cell bodies have not been destroyed, and treatment of the underlying cause has been successful, full recovery from neuropathy is possible.

Alternatives

Peripheral neuropathy is a general finding of the physical exam and is not a specific diagnosis. It must be differentiated from other possible diseases.

Appropriate specialists

Neurologist and neurosurgeon.

Last updated 15 December 2011