The carpal tunnel is a narrow passageway made of bones and ligaments that is located on the wrist. It houses the tendons that move the fingers and the median nerve. This nerve controls some small muscles of the hand that move the fingers and provides sensation to the thumb and some of the fingers.
Carpal tunnel syndrome develops when this nerve becomes compressed at the carpal tunnel on its way from the forearm to the hand. Thickening from inflamed tendons, cysts, tumors or other swellings can also narrow the tunnel and compress the nerve.
Other causes of carpal tunnel syndrome include wrist injuries like fractures and sprains which can also cause the nerve to be squeezed. Persons who are born with a small tunnel are also more likely to develop the syndrome.
Risk factors for developing carpal tunnel syndrome include pregnancy due to fluid retention. Arthritis, diabetes, hypothyroidism, overactivity of the pituitary gland and overuse of the wrist are other risk factors associated with this condition.
Hand pain, which may be associated with tingling or burning sensations on the palm, is one of the symptoms of carpal tunnel syndrome. Hand numbness is another symptom which may occur together with weakness of the hand muscles. This numbness mainly affects the thumb, index and middle fingers though it can also radiate up the forearm.
Carpal tunnel syndrome symptoms begin gradually and usually start at night since many people sleep with their wrists flexed. As the condition progresses, the tingling extends and is felt during the day.
Diagnostic tests used to confirm this syndrome include nerve conduction studies in which electrodes are placed on the hand and wrist. Small electric shocks are then applied and the speed with which the nerves transmit the impulses is measured. This electrodiagnositic test is the only examination that can accurately confirm the diagnosis.
Electromyography is another test which can also be done in patients with carpal tunnel syndrome. In this procedure a fine needle is inserted into a muscle and the electrical activity measured to determine the severity of damage to the median nerve.
The treatment of carpal tunnel syndrome should start with the treatment of any underlying condition like diabetes or arthritis. The wrist should then be rested for at least a fortnight and activities that can worsen the condition avoided. The wrist should also be immobilized in a splint to avoid twisting or bending movements that can further compress the nerve.
Nonsteroidal anti-inflammatory drugs (NSAIDS) are some of the medications used to treat carpal tunnel syndrome. Ibuprofen and naproxen are examples of these drugs which reduce inflammation and pain. Water pills or diuretics are also prescribed for patients with edema to reduce the swelling. Pyridoxine or vitamin B6 is also taken to reduce the symptoms.
Corticosteroids like prednisone can be injected into the wrist to reduce inflammation and pain. Lidocaine is another medication which is injected into the carpal tunnel to manage pain. This is called a carpal tunnel injection.
Physical therapy is also important for the management of this condition since stretching and strengthening exercises help manage the symptoms.
The surgical treatment of carpal tunnel syndrome includes the carpal tunnel release. In this operation the surgeon cuts the carpal ligament which is the band of tissue around the wrist to enlarge the tunnel and reduce the pressure on the nerve. This operation which is usually done under local anesthesia can also be done endoscopically with very small incisions to minimize postoperative discomfort and hasten recovery.
The symptoms of the syndrome are usually relieved immediately after the release operation though full recovery usually takes several months. Adverse effects of the operation include infection, nerve damage and pain at the scar.
To prevent further damage to the nerve patients should perform wrist stretching exercises. They should also take frequent rest breaks while at work and wear splints to keep their wrists straight and in the correct position. Fingerless gloves can also be worn to keep the hand warm and flexible.
It is important to treat carpal tunnel syndrome in order to prevent permanent damage to the median nerve since this can cause wasting of the thenar muscles at the base of the thumb. Progression of the disease can also lead to decreased grip strength which makes every day activities like grasping small objects difficult. In addition, the hand’s sensation can also be affected leading to inability to differentiate hot from cold temperatures.