Definition

Multiple mononeuropathy is a nervous system disorder that involves damage to at least two separate nerve areas. Neuropathy means damage to a peripheral nerve.

Alternative Names

Mononeuritis multiplex; Mononeuropathy multiplex; Multifocal neuropathy; Peripheral neuropathy - mononeuritis multiplex

Causes

Multiple mononeuropathy is a form of damage to one or more peripheral nerves. These are the nerves outside the brain and spinal cord. It is a group of symptoms (syndrome), not a disease.

However, certain diseases can cause the injury or nerve damage that leads to the symptoms of multiple mononeuropathy. Common conditions include:

• Blood vessel diseases such as polyarteritis nodosa
• Connective tissue diseases such as rheumatoid arthritis or systemic lupus erythematosus (the most common cause in children)
• Diabetes

Less common causes include:

• Amyloidosis, an abnormal buildup of proteins in tissues and organs
• Blood disorders (such as hypereosinophilia and cryoglobulinemia)
• Infections such as Lyme disease, HIV/AIDS, or hepatitis
• Leprosy
• Sarcoidosis, which also may cause inflammation of the lymph nodes, lungs, liver, eyes, skin, or other tissues
• Sjögren syndrome, a disorder in which the glands that produce tears and saliva are destroyed
• Granulomatosis with polyangiitis, an inflammation of the blood vessel

Symptoms

Symptoms depend on the specific nerves involved, and may include:

• Loss of bladder or bowel control
• Loss of sensation in one or more areas of the body
• Paralysis in one or more areas of the body
• Tingling, burning, pain, or other abnormal sensations in one or more areas of the body
• Weakness in one or more areas of the body

Exams and Tests

The health care provider will perform a physical exam and ask about the symptoms, focusing on the nervous system.

To diagnose this syndrome, there usually needs to be problems with two or more unrelated nerve areas. Common nerves affected are the:

• Axillary nerve in either arm or shoulder
• Common peroneal nerve in the lower leg
• Distal median nerve to the hand
• Femoral nerve in the thigh
• Radial nerve in the arm
• Sciatic nerve in the back of the leg
• Ulnar nerve in the arm

Tests may include:

• Electromyogram (EMG, a recording of electrical activity in the muscles)
• Nerve biopsy to examine a piece of the nerve under a microscope
• Nerve conduction tests to measure how fast nerve impulses move along the nerve
• Imaging tests, such as x-rays

Blood tests that may be done include:

• Antinuclear antibody panel (ANA)
• Blood chemistry tests
• C-reactive protein
• Imaging scans
• Pregnancy test
• Rheumatoid factor
• Sedimentation rate
• Thyroid tests
• X-rays

Treatment

The goals of treatment are to:

• Treat the illness that is causing the problem, if possible
• Provide supportive care to maintain independence
• Control symptoms

To improve independence, treatments may include:

• Occupational therapy
• Orthopedic help (for example, a wheelchair, braces, and splints)
• Physical therapy (for example, exercises and retraining to increase muscle strength)
• Vocational therapy

Safety is an important for people with sensation or movement problems. Lack of muscle control and decreased sensation may increase the risk for falls or injuries. Safety measures include:

• Having adequate lighting (such as leaving lights on at night)
• Installing railings
• Removing obstacles (such as loose rugs that may slip on the floor)
• Testing water temperature before bathing
• Wearing protective shoes (no open toes or high heels)

Check shoes often for grit or rough spots that may injure the feet.

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

People with multiple mononeuropathy are prone to new nerve injuries at pressure points such as the knees and elbows. They should avoid putting pressure on these areas, for example, by not leaning on the elbows, crossing the knees, or holding similar positions for long periods.

Medicines that may help include:

• Over-the-counter or prescription pain drugs
• Antiseizure or antidepressant drugs to reduce stabbing pains

Outlook (Prognosis)

A full recovery is possible if the cause is found and treated, and if the nerve damage is limited. Some people have no disability. Others have a partial or complete loss of movement, function, or sensation.

Possible Complications

Complications may include:

• Deformity, loss of tissue or muscle mass
• Disturbances of organ functions
• Medicine side effects
• Repeated or unnoticed injury to the affected area due to lack of sensation
• Relationship problems due to erectile dysfunction

When to Contact a Medical Professional

Contact your provider if you notice signs of multiple mononeuropathy.

Prevention

Preventive measures depend on the specific disorder. For example, with diabetes, eating healthy foods and keeping a tight control of blood sugar may help prevent multiple mononeuropathy from developing.

References

Katirji B. Disorders of peripheral nerves. In: Jankovic J, Mazziotta JC, Pomeroy SL, Newman NJ, eds. Bradley and Daroff's Neurology in Clinical Practice. 8th ed. Philadelphia, PA: Elsevier; 2022:chap 106.

Smith G, Shy ME. Peripheral neuropathies. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 392.