Carpal Tunnel Syndrome

The carpal tunnel is a tunnel in the palmar side of the wrist. The flexor tendons and the median nerve run through this tunnel. The median nerve supplies feeling to the thumb, index, middle and half of the ring finger. It also supplies strength to some of the muscles that move the thumb and fingers. The flexor tendons join the flexor muscles to the bones and allow one to bend the fingers and the thumb.

Carpal tunnel syndrome is a compressive neuropathy where the median nerve gets compressed as it runs through this tunnel. The causes of this are either that the contents of the tunnel are increased (swelling, bleeding, etc.), or that the roof of the tunnel gets thickened. The roof of the tunnel is called the transverse carpal ligament, and thickening of this is the most common cause of carpal tunnel syndrome.

Symptoms of carpal tunnel syndrome include numbness, pins and needles, occasional pain and weakness of the hand. Classically these symptoms are worse at night and when doing certain activities such as driving. It normally has a gradual onset and gets worse over months or years. It can also appear in pregnancy but usually gets better after the pregnancy is over. Often the affected person is awoken at night with a numb painful hand. Symptoms are usually bad in the mornings as well.

Treatment of mild symptoms is conservative. This involves activity modification, a wrist brace and possibly a corticosteroid injection. If this fails or in advanced cases, surgery is required. Surgery involves a carpal tunnel release, and can be performed under local or general anaesthetic and is usually a day procedure. Results of the surgery are very good, and the improvement of symptoms are often seen within a day.

Carpal tunnel syndrome in pregnancy occurs due to fluid retention and usually gets better after the pregnancy. Therefore, surgery is avoided. The management rather involves corticosteroid injections and splinting.