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.

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