Carpal Tunnel Syndrome
The carpal tunnel is the passageway in the wrist and consists of the arching carpal bones (eight bones in the wrist) and the ligament connecting the pillars of the arch (the transverse carpal ligament). The median nerve and the tendons that connect the fingers to the muscles of the forearm pass through the narrow tunnel.
Carpal tunnel syndrome occurs when the median nerve is compressed because of swelling of the nerve or tendons or both. The median nerve provides sensation to the palm side of the thumb, index, middle finger, and the inside half of the ring finger. It also gives power to, or innervates, muscles in the forearm and hand that allow a pincher grasp (the ability to grasp an object between the thumb and forefinger). When this nerve becomes impinged, or pinched, numbness, tingling, and sometimes pain of the affected fingers and hand may occur and radiate into the forearm.
While there are many possible causes of carpal tunnel syndrome, the vast majority of people with the condition have no known cause. Any condition that puts pressure on the median nerve at the wrist can cause the syndrome. We do know that excessive repetitive movements of the wrists and hands (such as uninterrupted prolonged typing) can trigger the symptoms of carpal tunnel syndrome. Untreated, the symptoms can become chronic, but when detected early, carpal tunnel syndrome can be treated more easily and recovery is possible in a few months. Severe carpal tunnel syndrome can also be treated, but recovery may take up to a year or longer and may not be complete.
What Are the Symptoms of Carpal Tunnel Syndrome?
Usually, people with carpal tunnel syndrome first notice that their fingers "fall asleep" and become numb at night. The reason they may experience symptoms at night may be the relaxed flexed position of the hand and wrist while sleeping, or the accumulation of fluid that may put pressure around the joint. They often wake up with numbness and tingling in their hands. The feeling of burning pain and numbness may generally run up the center of the person's forearm, sometimes as far as the shoulder. Carpal tunnel syndrome may be temporary and resolve by itself or become persistent and worsen over time.
What Happens in Severe Cases of Carpal Tunnel Syndrome?
As carpal tunnel syndrome becomes more severe, a person may have decreased grip strength with atrophy, or wasting, of the muscles in the hand. Pain and muscle cramping become more severe. The median nerve itself begins to deteriorate with chronic irritation or pressure around it. This results in a slowing of nerve impulses, loss of feeling in the fingers, and a loss of strength and coordination at the base of the thumb. If the condition is not treated, it could result in permanent deterioration of muscle tissue and loss of hand function.