Mononeuropathy
Mononeuropathy involves loss of movement or sensation to an area
caused by damage to a single nerve or nerve group e.
Mononeuropathy involves damage or destruction of an isolated nerve or nerve group. It
is a type of peripheral neuropathy (damage
to nerves outside the brain and spinal cord).
Causes of Mononeuropathy
Physical injury is the most common cause of a mononeuropathy. Often, the
injury is caused by prolonged pressure on a nerve that runs close to the surface of the
body near a bony prominence, such as a nerve in an elbow, a shoulder, a wrist, or a knee.
Pressure on a nerve during a long, sound sleep (especially in alcoholics) may be prolonged
enough to cause damage. Pressure may result from a misfitting cast, improper use of
crutches, or staying in a cramped position for a long time, such as when gardening or when
playing cards with the elbows resting on a table. Damage due to pressure may also occur in
people who are under anesthesia for surgery, in those who are bedridden (particularly
older people), and in those who are paralyzed.
Less commonly, strenuous activities, accidents, prolonged exposure to cold
or heat, or radiation therapy for cancer may also damage a nerve. Repeated injuries, such
as those due to tight gripping of small tools or to excessive vibration from an air
hammer, can also damage nerves. Infections, such as leprosy and Lyme disease, may destroy
a nerve, causing mononeuropathy. Cancer may cause mononeuropathy by directly invading a
nerve. Some toxic substances and some drugs can cause mononeuropathy.
Certain peripheral nerves are more vulnerable to injury. Examples are the
median nerve in the wrist (resulting in carpal tunnel syndrome , the ulnar nerve in the
elbow, the radial nerve in the upper arm, and the peroneal nerve near the knee.
Treatment of Mononeuropathy
Treatment is aimed at maximizing the ability to use the affected
body part. The cause should be identified and treated as appropriate. In some cases, no
treatment is required and recovery is spontaneous. Vascular lesions (injuries to an
artery) can often affect a single nerve, and in these cases the cause of the vasculopathy
(such as high blood pressure or diabetes) should be treated.
If there is no history of trauma to the area, conservative treatment is indicated if there
was sudden onset, minimal sensation changes, no difficulty in movement, and no test
results indicating degeneration of the nerve axon.
Corticosteroids injected into the area may reduce swelling and pressure on the nerve in
some cases. Surgical intervention is indicated if the symptoms are caused by entrapment of
the nerve. Surgical removal of lesions that press on the nerve may help in |
