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

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)

• 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

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.