Assess
& Address: Carpal
Tunnel Syndrome
by Whitney Lowe |
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Assessment
& Evaluation
The most common symptoms of CTS include pain, numbness
or paresthesia in the median-nerve distribution of the hand. Symptoms
are often worse at night due to the tendency of people to bend
their wrists into flexion while sleeping. This position increases
pressure within the carpal tunnel. Wrist splints are sometimes
worn at night to keep the wrist in a neutral position.
If the condition worsens,
the client may complain of a loss of tactile sensitivity in the
fingers. Eventually, motor dysfunction will appear and is evidenced
by clumsiness, loss of dexterity, and weakening of grip strength
in the hand. The median nerve innervates most of the finger-flexor
muscles. Thus, grip strength is affected. Continued aggravation
of motor symptoms may produce some visible atrophy of the muscles
in the hand as well.
Sensory symptoms, such
as numbness, paresthesia or pain, are likely to occur before the
motor symptoms of muscle weakness. The symptoms are more often
sensory than motor in CTS because the median nerve at the wrist
is composed of more than 90 percent sensory fibers and less than
10 percent motor fibers. Therefore, if motor symptoms are present,
it is usually an indication of greater damage from the nerve compression.
The shape of the wrist
(as viewed in a cross section) may contribute to the development
of CTS. If the wrist is oval-shaped, there is more space within
the tunnel and symptoms are less likely to develop. If the wrist
is square-shaped, there is a greater chance of tissues being compressed
within the tunnel. The shape of the wrist is determined by the
ratio between the width and height of the wrist.
Physicians often evaluate
CTS with electrodiagnostic tests. The most common of these is
one that measures the nerve-conduction velocity. If there is a
slowing of the rate of nerve conduction near the carpal tunnel,
CTS is assumed. However, electrodiagnostic tests are not considered
reliable enough on their own to determine CTS. It is important
for the person to be evaluated for a pattern of symptoms that
are consistent with true CTS.
Several
physical-examination procedures are commonly used to identify
CTS. The most common is the Phalen’s test (see Figure 1,
left). In this test, the client presses the backside of his/her
hands together and holds them for about 60 seconds. If neurological
symptoms are reproduced along the median-nerve distribution, there
is a good indication the client has CTS.
Another
procedure used for identifying CTS is the tethered median-nerve
stress test. In this procedure, the wrist is held in extension
or partial hyperextension. The practitioner will pull the index
finger into hyperextension as far as the client’s range
of motion will allow (see Figure 2, right). If this movement reproduces
the client’s pain or neurological symptoms, it is considered
a positive indication of CTS.
The condition may also
be evaluated by applying direct pressure over the carpal tunnel
to reproduce symptoms. The pressure does not need to be great
in order to elicit the symptoms if the person has CTS. Applying
pressure over the carpal tunnel in this fashion is sometimes called
the carpal-compression test.
References