Excessive repetitive movements of the arms, wrists or hands can
cause injuries that could become chronic conditions. When detected early enough,
however, hand-wrist injuries can be treated, and recovery is possible in a few
months. Severe hand injuries can also be treated, but recovery may take up to a
year or longer.
This article summarizes one of the most common hand problems: carpal tunnel
syndrome. It also includes a brief summary of some of the conditions often
associated with carpal tunnel syndrome.
What is carpal tunnel syndrome?
The carpal tunnel is the passageway in the hand made up of the median nerve, tendons
and the carpal bones (eight bones in the wrist). Carpal tunnel syndrome occurs
when the nerve passing through the wrist (called the median nerve) becomes
pinched by irritated, swollen tendons. The swollen tendons put pressure on the
median nerve where it passes through the gap under a ligament in front of the
wrist. This pressure causes numbness and pain in the middle fingers.
What are the symptoms of carpal tunnel syndrome?
Usually, people with carpal tunnel syndrome first notice that their fingers "fall asleep" and become numb at night -- they often wake up with numbness and tingling in their hands. Burning pain is frequently associated with this feeling of numbness, and it generally runs up the center of the person's forearm, sometimes as far as the shoulder. As carpal tunnel syndrome becomes more severe, symptoms are noticed during the day.
What happens in severe cases of carpal tunnel syndrome?
When chronic irritation occurs around the median nerve, it becomes constricted and is
continually pushed against the ligament above it. When the median nerve in the
hand is continually constricted, it can become compressed to the point that it
begins to deteriorate. This results in a slowed transmittal of nerve impulses,
which may cause a loss of feeling in the fingers and a loss of muscle function
at the base of the thumb. If the condition is not treated, it could result in a
deterioration of muscle tissue.
Do certain conditions make people more likely to develop carpal tunnel syndrome?
Yes. People with diabetes or metabolic conditions may be more likely to develop
carpal tunnel syndrome. These conditions affect the nerves directly, making the
nerves more vulnerable to compression.
How is carpal tunnel syndrome treated?
Treatment first involves adjusting the way the person performs the repetitive motion by:
- Changing the frequency with which the person performs the motion.
- Changing the amount of time the person rests between periods of performing
the motion.
Treatment also includes immobilizing the wrist in a splint to minimize or
prevent pressure on the nerves. Splints that support the wrist in a comfortable
neutral position can be of great value if worn at night to relieve painful
numbness or tingling.
Patients may be given short courses of anti-inflammatory drugs or injections
of cortisone or steroids in their wrist to reduce swelling. Injections are
usually temporary and are best reserved for people who have carpal tunnel
syndrome as a result of an acute (sharp or severe) flare-up of tenosynovitis (an
inflammation of the sheath around the tendon). Injections are also used to treat
people who have an inflammatory disease, such as rheumatoid arthritis.
If carpal tunnel syndrome does not respond to conservative treatment, then
surgery is the next treatment option. During surgery, your doctor will open the
carpal tunnel and cut the ligament at the bottom of the wrist, relieving the
pressure.
Carpal tunnel surgery is quite effective when the condition only involves
nerve constriction. Relief of painful symptoms is excellent and nerve
degeneration is almost always reversible.
When carpal tunnel syndrome is just one symptom of a more serious disorder,
the results of surgery are not always very good. The difficulty is not
in recovering from the operation, but in recovering the ability to return to
work, especially to the same job that caused the disorder to occur.
Whether or not true carpal tunnel symptoms recur in these patients, many
continue to have pain and are unable to use their hands to any great extent.
What tests can help your doctor diagnose carpal tunnel syndrome?
Often, an electromyogram that includes nerve conduction studies is done to document
the extent of nerve damage. An electromyogram is a test that measures the
electrical activity in your nerves and muscles. The nerve conduction studies
measure the ability of specific nerves to transmit electrical impulses, or messages, to muscles.
The nerve conduction studies, however, will not become positive until there
is significant nerve damage (degeneration). In addition, the severity of a
person's symptoms are often not correlated with the findings of a nerve
conduction study.
What are some conditions that are often associated with carpal tunnel syndrome?
De Quervain's Disease
One very frequent condition seen in clerical workers and in patients
who continuously perform pinching maneuvers is De Quervain's disease. This is a
stenosing tenosynovitis (an inflammation of the sheath around the tendon
resulting from constriction of tendon motion), which occurs at the base of the thumb.
If it is not possible to treat this condition by preventing the strain, it
can usually be treated with splinting and anti-inflammatory medication. Usually,
a splint is used. The splint holds the base of the thumb but allows motion in the
fingers. Persistent cases are treated with an injection of steroid medication
into the compartment around the tendon. This is generally a very successful
method of treatment, but there is a relatively high incidence of recurrence
because of the persistent mechanical problem.
Surgery is usually reserved for patients who cannot function reasonably
after they have received repeated conservative treatment. One complication of
surgery is pain due to scar tissue that surrounds the branch of the radial
nerve, which runs directly over the thumb tendon.
Trigger Finger
Another form of stenosing tenosynovitis is the "trigger finger."
This occurs around the flexor tendons, generally in the palm where the first
pulley exists. The patient develops a chronic thickening due to inflammation
underneath this pulley, and the tendon then becomes rough on the surface
(forming a nodule). As this roughening develops, there is a disparity in the
space that is present, and the tendon just can't get back and forth through
this tight compartment.
This results in "snapping" at first, with flexion (decreased
movement of the finger). If the condition becomes severe enough, the finger can
become "locked." This occurs because the nodule which develops on the
tendon passes through the pulley with flexion and then can't be passively
stretched back out again with extension.
If the condition is very mild, splinting and anti-inflammatory medications
can be very effective. However, if enough thickening has developed, it is
usually necessary to inject steroid medications to dissolve some of the
thickened fluid that is deposited on the tendon.
If the condition becomes significantly chronic to the point that thickening
of the pulley develops, then it will not respond to injection of steroid
medications. In this case, surgery must be performed to release the pulley.
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 9/20/2006…#4005
