Carpal Tunnel Syndrome (CTS) is caused by nerve compression at the wrist when it passes through the carpal tunnel on the palm side of the wrist (Figure 1).
Figure 1 Nerve compression at the carpal tunnel
The carpal tunnel is a passageway for nerves and tendons that control finger sensations and movements respectively.
Swelling or thickening of structures in or around the carpal tunnel may press on the median nerve, leading to tingling, numbness, pain and weakness, usually most prominent over the first three fingers.
Carpal tunnel syndrome (CTS) is the most common peripheral nerve entrapment syndrome, and is characterized by numbness and tingling of the radial 3½ digits. It is found in one percent of the general population and increased incidence is noted in women, the elderly and pregnant patients.
CTS symptoms often develop gradually and is more severe in the dominant hand.
The first symptoms include tingling or numbness of the thumb, index and middle fingers which may come and go initially. You may also experience weakness in hand grip with the tendency to drop objects. It may first be noticedwhen holding objects or driving.
Commonly, it improves with shaking of the affected hand. Occasionally, there may be pain or an abnormal feeling that the hand "is swollen”.
Over time, the condition may worsen and result in persistent numbness, permanent weakness and wasting of the thumb muscles.
Nerve conduction study is frequently done to confirm the diagnosis. It usually takes about 30 to 45 minutes and does not require anaesthesia. During the test, small and safe doses of electric currents are delivered to stimulate the nerves in order to assess their function.
A peripheral nerve ultrasound may also be done to confirm nerve compression.
Mild to moderate cases of CTS may be managed in various ways:
In moderate or advanced stages where there is significant nerve damage, surgery may be advised to relieve symptoms and prevent further damage. The outcome for surgery is generally good for most patients.
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