|
What
is Carpal Tunnel Syndrome?
What conditions and
diseases cause carpal tunnel syndrome?
How does a patient with carpal tunnel syndrome feel?
How is carpal tunnel syndrome diagnosed?
How is carpal tunnel syndrome treated? |
 |
What
is Carpal Tunnel Syndrome?
Carpus is a word derived from the Greek word "karpos" which
means "wrist." The wrist is surrounded by a band of fibrous
tissue which normally functions as a support for the joint. |
|
 |
|
The
carpal tunnel (pink area in the picture) is made up of several
bones (white) connected by ligaments. The largest of these is
the Transverse Carpal Ligament (blue). These structures form
the perimeter of a passage called the carpal tunnel (also called
the carpal canal). The floor of the carpal tunnel is formed
by the carpal bones and the roof by the transverse carpal ligament.
Through this tunnel run nerves, tendons, blood and other soft
tissues.
The median nerve passes through the carpal tunnel to reach the
thumb, index, and middle fingers of the hand. Any condition
that causes swelling or a change in position of the tissue within
the carpal tunnel can squeeze and irritate the median nerve.
Irritation of the median nerve causes tingling and numbness
of the thumb, index, and the middle fingers, a condition known
as "carpal tunnel syndrome."
(Anatomy similar to that of the wrist and hand exists in the
ankle and foot. Tarsal is a word from Latin which means ankle.
When the sensory nerve that passes through the tarsal tunnel
is irritated, numbness and tingling of the foot and toes can
be felt This condition is referred to as "tarsal tunnel
syndrome" It is an analogous to, but far less common than,
carpal tunnel syndrome). Top |
|
|
|
What
conditions and diseases cause carpal tunnel syndrome?
For most patients, the cause of their carpal tunnel syndrome is
unknown. Any condition that exerts pressure on the median nerve
can cause carpal tunnel syndrome. Common conditions that can lead
to carpal tunnel syndrome include obesity, pregnancy, hypothyroidism,
arthritis, diabetes, and trauma. Tendon inflammation resulting from
repetitive work such as prolonged typing can also cause carpal tunnel
symptoms. Some rare diseases can cause deposition of abnormal substances
in and around the carpal tunnel, leading to nerve irritation These
diseases include amyloidosis, sarcoidosis, multiple myeloma and
leukemia. Top
How does a patient with carpal tunnel syndrome feel?
Patients with carpal tunnel syndrome initially feel numbness and
tingling of the hand in the distribution of the median nerve (the
thumb, index, middle, and part of the fourth fingers). These sensations
are often more pronounced at night and can awaken patients from
sleep. The reason symptoms are worse at night may be related to
the flexed-wrist sleeping position and/or fluid accumulating around
the wrist and hand while lying flat.
|
|
 |
|
As
the disease progresses, patients can develop a burning sensation,
cramping and weakness of the hand. Decreased grip strength
can lead to frequent dropping of objects from the hand. Occasionally,
sharp shooting pains can be felt in the forearm. Chronic carpal
tunnel syndrome can also lead to wasting (atrophy) of the
hand muscles. Top
How
is carpal tunnel syndrome diagnosed?
The diagnosis of carpal tunnel syndrome is suspected based
on the symptoms and distribution of the hand numbness. Examination
of the neck, shoulder, elbow, pulses, and reflexes can be
performed to exclude other conditions that can mimic carpal
tunnel syndrome. The wrist can be examined for swelling, warmth,
tenderness, deformity, and discoloration. Sometimes tapping
the front of the wrist can reproduce tingling of the hand,
and is referred to as Tinel's sign of carpal tunnel syndrome.
Symptoms can also at times be reproduced
by bending the wrist forward, and is referred to as Phalen's
maneuver (Phalen's
maneuver).
The diagnosis is strongly suggested when a nerve conduction
test is abnormal. This test involves measuring the rate of
speed of electrical impulses as they travel down a nerve.
In carpal tunnel syndrome, the impulse slows as it crosses
through the carpal tunnel. Blood tests may be performed to
identify medical conditions associated with carpal tunnel
syndrome. These tests include thyroid hormone levels, completeblood
counts, and blood sugar and protein analysis. X-ray tests
of the wrist and hand might also be helpful. Top
|
|
|
|
How
is carpal tunnel syndrome treated?
The choice of treatment for carpal tunnel syndrome depends on the
severity of the symptoms and the underlying disease causing the
symptoms. Initial
treatment usually includes rest, immobilisation of the wrist in
a splint, and occasionally ice application. Patients whose occupations
are aggravating the symptoms should modify their activities. For
example, computer keyboards and chair height may need to be adjusted
to optimise comfort. Underlying conditions or diseases are treated
individually. Fractures can require orthopaedic management. Obese
individuals will be advised regarding weight reduction. Rheumatoid
disease is treated with measures directed against the underlying
arthritis. Wrist swelling, which can be associated with pregnancy,
resolves after delivery of the baby!
Several
types of medications have been used in the treatment of carpal tunnel
syndrome. Vitamin B6 (pyridoxine) has been reported to relieve some
symptoms of carpal tunnel syndrome, although it is not known how
this medication works. Nonsteroidal anti-inflammatory drugs can
also be helpful in decreasing inflammation and reducing pain. Side
effects include gastrointestinal upset and even ulceration of the
stomach. These medications should be taken with food and abdominal
symptoms should be reported to the doctor Corticosteroids can be
given by mouth or injected directly into the wrist joint. They can
bring rapid relief of the persistent symptoms of carpal tunnel syndrome.
Side effects of these medications when given in short courses for
carpal tunnel syndrome are minimal. However, corticosteroids can
aggravate diabetes and should be avoided in the presence of infections
Most
patients with carpal tunnel syndrome improve with conservative measures
and medications. Occasionally, chronic pressure on the median nerve
can result in persistent numbness and weakness. In order to avoid
serious and permanent nerve and muscle consequences of carpal tunnel
syndrome, surgical treatment is considered. Surgery involves severing
the band of tissue around the wrist to reduce pressure on the median
nerve. This surgical procedure is called "carpal tunnel release"
It can be performed with a
small diameter viewing tube, called an arthroscope, or by open wrist
procedure. After carpal tunnel release, patients often undergo exercise
rehabilitation. Though it is uncommon, symptoms can recur.
Back to top
|
| |
|
