Mononeuritis multiplex is a form of peripheral neuropathy (damage to nerves outside the brain and spinal cord). It involves isolated damage to at least 2 separate nerve areas. Mononeuritis multiplex is a group of symptoms, not a distinct disease entity. The underlying disorder affects isolated nerves in multiple, random areas. As the disorder worsens, the damage may become more diffuse and less focused on particular areas, resembling polyneuropathy.
The damage to the nerves involves destruction of the axon (part of the nerve cell), which interferes with nerve conduction at the location of the damage. Common causes include a lack of oxygen caused by decreased blood flow or inflammation of blood vessels. No cause is identified for about one-third of cases.
Diabetes mellitis is a common cause of mononeuritis multiplex. Several other disorders are also associated with mononeuritis multiplex, including (but not limited to) blood vessel diseases such as polyarteritis nodosa and connective tissue diseases such as rheumatoid arthritis or systemic lupus erythematosus. Connective tissue disease is the most common cause in children.
Less common causes include the following:
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