Mononeuritis multiplex

Definition

Mononeuritis multiplex is a neurological disorder that involves damage to at least two separate nerve areas.

Alternative Names

Causes

Mononeuritis multiplex is a form of peripheral neuropathy (damage to nerves outside the brain and spinal cord). Mononeuritis multiplex is a group of symptoms, not a disease. The damage to the nerves involves destruction of the axon (part of the nerve cell), which interferes with nerve signaling

The underlying cause of the mononeuritis multiplex affects nerves in multiple, random areas. As the disorder worsens, the damage may become more widespread. Common causes include a lack of oxygen caused by decreased blood flow or inflammation of blood vessels. No cause is identified for about a third of cases.

Common causes of mononeuritis multiplex:

• Diabetes mellitus
• Blood vessel diseases such as polyarteritis nodosa
• Connective tissue diseases such as rheumatoid arthritis or systemic lupus erythematosus

Connective tissue disease is the most common cause of mononeuritis multiplex in children.

Less common causes include:

• Sjogren syndrome
• Wegener's granulomatosis
• Leprosy
• Sarcoidosis
• Amyloidosis
• Forms of diabetic neuropathy
• Disorders of the blood (such as hypereosinophilia and cryoglobulinemia)

Symptoms

• Numbness and tingling
• Abnormal sensation
• Burning pain
• Lack of or decreased sensation in any part of the body
• Difficulty moving a part of the body (paralysis)
• Lack of control of movement of a part of the body
• Inability to move a part of the body

Exams and Tests

A detailed history may be required to determine the possible cause of the disorder. Examination and neuromuscular testing may show a specific loss of sensation and movement associated with dysfunction of specific nerves. Reflexes may be abnormal.

Diagnosis of mononeuritis multiplex usually involves deficits of two or more isolated, unrelated nerve areas. Common findings may include the following:

• Sciatic nerve dysfunction
• Common peroneal nerve dysfunction
• Radial nerve dysfunction
• Ulnar nerve dysfunction
• Femoral nerve dysfunction
• Distal median nerve dysfunction
• Axillary nerve dysfunction

Tests that may be done include:

• Nerve conduction velocity
• EMG
• Nerve biopsy

Other blood tests, x-rays, and imaging tests may be done.

Treatment

The goals of treatment include treatment of the cause if possible, supportive care to maximize independence and control of symptoms. This may include control of blood sugar levels for diabetics, nutritional supplementation, or medical treatments of conditions as appropriate.

To maximize self-care and independence, physical therapy, vocational therapy, occupational therapy and orthopedic interventions may be recommended. For example, exercises and retraining may increase muscle strength and control. Appliances such as wheelchairs, braces, and splints may enhance mobility.

Safety is an important consideration for people with sensation or movement difficulties. Lack of muscle control may increase the risk of falls or other injury. Decreased sensation can also increase the risk of falls. It may also increase the risk of injury because the person is unable to perceive a potential source of harm.

Safety measures for people with movement difficulty may include railings, removal of obstacles (such as loose rugs that may slip on the floor) and other measures as appropriate.

Safety measures for persons with limited sensations include an awareness of the lack of sensation and compensation through other measures. Specific measures may include the use of adequate lighting (including lights left on at night), testing of water temperature before bathing, the use of protective shoes (no open toes or high heels), and similar measures. Shoes should be checked often for grit or rough spots that may injure the feet.

People with decreased sensation should check their feet (or other affected area) frequently for bruises, open skin areas, or other injuries that may go unnoticed and become severely infected because the pain nerves of the area are not signalling the injury.

People with mononeuropathy multiplex are prone to new nerve injury at pressure points such as knees and elbows. They should avoid prolonged pressure on these areas caused by leaning on the elbows, crossing the knees, or holding similar positions.

Over-the-counter analgesics or prescription pain medications may be needed to control pain (neuralgia). Various other medications may be used to reduce the stabbing pains that some people experience, including anticonvulsants (gabapentin

Positioning, the use of frames to keep bedclothes off of a tender body part, and other measures may be helpful to control pain. Autonomic symptoms may occur and can be treated symptomatically. These may be difficult to treat or respond poorly to treatment, however.

Outlook (Prognosis)

If the cause can be identified and successfully treated, and if damage is limited, there is a possibility of full recovery from mononeuritis multiplex. The extent of disability varies from no disability to partial or complete loss of movement, function, or sensation.

Nerve pain may be quite uncomfortable and persist for a prolonged period of time. If this occurs, see a pain specialist to ensure that all options for pain treatment are available to you.

Possible Complications

• Recurrent or unnoticed injury to any part of the body
• Deformity, loss of tissue mass
• Disturbances of organ functions
• Decreased self-esteem
• Relationship problems associated with impotence

When to Contact a Medical Professional

Call your health care provider if you notice signs of mononeuritis multiplex.

Prevention

Prevention techniques vary depending on the specific disorder. Proper diet and use of medication for diabetes may help prevent neuropathy from developing.