Neuritis, Peripheral

Also known as multiple neuritis, peripheral neuropathy, and polyneuritis, peripheral neuritis is the degeneration of peripheral nerves supplying mainly the distal muscles of the extremities. It results in muscle weakness with sensory loss and atrophy, and decreased or absent deep tendon reflexes. This syndrome is associated with a non-inflammatory degeneration of the axon and myelin sheaths, chiefly affecting the distal muscles of the extremities.

Although peripheral neuritis can occur at any age, its incidence is highest in men between the ages of 30 and 50. Because onset is usually insidious, patients may compensate by overusing unaffected muscles; however, onset is rapid with severe infection and chronic alcohol intoxication. If the cause can be identified and eliminated, the prognosis is good.

Causes

Causes of peripheral neuritis include:

• chronic intoxication (ethyl alcohol, arsenic,lead, carbon disulfide, benzene, phosphorus, and sulfonamides)
• infectious diseases (meningitis, diphtheria, syphilis, tuberculosis, pneumonia, mumps, and Guillain-Barre syndrome)
• metabolic and inflammatory disorders (gout, diabetes mellitus, rheumatoid arthritis, polyarteritis nodosa, systemic lupus erythematosus)
• nutritive diseases (beriberi and other vitamin deficiencies and cachectic states).

Signs and symptoms

• Skin sensation (i.e., numbness, tingling, pins and needles)
• Pain (neuralgia)
• Weakness
• Even paralysis of muscles in the area affected

Diagnosis

The patient history and physical examination delineate the characteristic distribution of motor and sensory deficits. Electromyography may show a delayed action potential if this condition impairs motor nerve function.

Treatment

Effective treatment of peripheral neuritis consists of supportive measures to relieve pain, adequate bed rest, and physical therapy as needed. Most important, the underlying cause must be identified and corrected. For instance, it's essential to identify and remove the toxic agent, correct nutritional and vitamin deficiencies (the patient needs a high­calorie diet rich in vitamins, especially B complex), or counsel the patient to avoid alcohol.

Prevention

If a prolonged procedure or immobility is expected, appropriate measures (such as padding vulnerable areas) can be taken beforehand to reduce the risk of nerve problems.

Some people have a hereditary predisposition for neuropathy. Such people need to be especially careful to limit alcohol and manage other medical problems closely.

All people can reduce the risk of neuropathy through a balanced diet, drinking alcohol in moderation, and maintaining good control of diabetes and other medical problems, if present.