The Carpal Tunnel is a passageway in the wrist formed by eight carpal (wrist)bones which make up the floor and sides of the tunnel, and the transverse carpal ligament, a strong ligament streatching across the roof of the tunnel. Inside the tunnel are nine flexor tendons which bend down your fingers and thumb. Also running through the carpal tunnel is the median nerve, a cord about the size of a pencil containing thousands of nerve fibers supplying feeling to your thumb, index and middle fingers, and half to the ring finger. The median nerve lies directly beneath the transverse carpal ligament and comes in contact with the ligament when bending or straightening the wrist or fingers.
Carpal Tunnel Syndrome is caused by increased pressure in the carpal tunnel resulting compression of the median nerve. Thickening of the tendons can restrict the space within the tunnel and cause the nerve to become pressed against the ligament forming the roof to the tunnel. When the relatively soft structure of the median nerve is pushed up against the ligament, blood flow to the nerve is restricted, causing a sensation often descirbed as "pins and needles" to the fingers. In severe or chronic cases, numbness can occur.
Carpal Tunnel syndrome can be caused by many types of problems, such as: inflammation or swelling of the tendon, wrist fractures and dislocations, diabetes, pregancy, rheumatiod arthritis, repetitive work activities.
Symptoms and signs are numbness, burning, or tingling of one or more of the fingers. This pain and numbness can happen at any time and often the symptoms occur at night and my awaken the person from sleep. A partial relief can sometimes be gained by shaking, massaging or elevating the affected hand. At times, the pain may extend up the arm, into the elbow, and as far up as the shoulder and neck.