Carpal Tunnel Syndrome
Carpal tunnel syndrome is relatively frequent unpleasant situation, which is closely related to the function of wrist. Therefore, to understand this syndrome, it is necessary to know some basic information about the anatomy of the wrist.
The wrist in a cross section has shape of a channel that contains tendons, blood vessels and the median nerve. The median nerve significantly participates in locomotion and sensitivity of the fingers and palm of the hand. It has a great importance in locomotion of the thumb, index finger and middle finger. The nerve is located relatively shallow beneath the skin.
The base and sides of the carpal tunnel are made of local bones; the upper part is open and covered by a fibrous band known as transverse carpal ligament. The carpal ligament is covered only by skin and thin layer of subcutaneous tissue.
The syndrome is caused by narrowing of the carpal tunnel that is associated with local compression of the median nerve. There are many possible causes of the narrowing. Most typically, it is a consequence of long-term overload of the wrist, which is typical for heavy manual work (workers with pneumatic drill) and for long-term work with a computer (especially the hand controlling the mouse). In addition, the narrowing occurs in certain autoimmune diseases (e.g. in rheumatoid arthritis) and hormonal changes in the body (pregnancy, menopause, underactive thyroid, acromegaly).
The syndrome manifests with gradually increasing problems. The patient suffers from tingling sensation in the affected hand, numbness, local pain and reduced muscle strength. The pain initially occurs at night at it may wake the affected person from sleep. The sick hand becomes less handy in manipulation with objects.
The diagnosis should be considered in patients suffering from the above symptoms. A simple compression test may help – we press the examined wrist from above for a short while and the test is positive when this leads to occurrence of symptoms. When there is a suspicion, the physician may indicate other tests. Perhaps the most valuable of these is the electromyography (EMG), which evaluates the conduction of neuroelectric signals through nerve fibers towards the muscles.
The syndrome can be prevented by avoiding the overload of wrists at work, especially when working with a computer; it is advisable to use a soft pad under the wrist and to do regular breaks.
In early stages, it is possible to locally inject corticosteroids to relieve the pain and other symptoms. The best solution, however, is a surgical procedure. It is a small surgical intervention, which may be performed with only local anesthesia. During surgery, the skin, subcutaneous tissue and transverse carpal ligament are carefully cut, which removes the compression of the median nerve and solves the situation.