(See also Overview of the Peripheral Nervous System.)
Multiple mononeuropathy typically affects only a few nerves, often in different areas of the body. In contrast, polyneuropathy affects many nerves, usually in about the same areas on both sides of the body. However, if multiple mononeuropathy involves many nerves, it may be difficult to distinguish from polyneuropathy.
Several disorders can cause multiple mononeuropathy, and each disorder produces characteristic symptoms.
The most common cause is probably
-
Diabetes, although diabetes more commonly causes polyneuropathy
Other common causes of multiple mononeuropathy include
-
Vasculitis (inflammation of blood vessels, as occurs in polyarteritis nodosa)
-
Systemic lupus erythematosus (lupus)
-
Infections (such as Lyme disease and HIV infection)
-
Direct invasion of the nerve by bacteria, as occurs in leprosy
A disorder may affect the nerves all at once or affect them progressively, a few at a time.
People have pain, weakness, abnormal sensations, or a combination of these symptoms in the areas supplied by the affected nerves. Symptoms often begin on one side of the body. When diabetes is the cause, nerves anywhere in the body can be affected, and as a result, weakness may affect any muscle.
Doctors diagnose multiple mononeuropathy based on symptoms and results of a physical examination, but electromyography and nerve conduction tests are usually done to do the following:
Blood tests may be done to identify a disorder causing multiple mononeuropathy.
Treatment of multiple mononeuropathy depends on the cause.
