Carpal Tunnel Syndrome
This condition is caused by trapping of the median nerve as it passes from the forearm into the hand through the carpal tunnel at the level of the wrist. The floor and sides of the tunnel are formed by the bones of the wrist joint and the roof of the carpal tunnel is formed by a tough ligament (the transverse carpal ligament ). When the space in the carpal tunnel becomes compromised the median nerve is compressed as the other structures in the tunnel (9 flexor tendons) are incompressible. The patient complains very typically of pain and tingling affecting the palmar surfaces of the thumb, index, long and adjacent ring fingers. The pain and tingling almost always occurs at night for reasons that are not clear. The compression can be severe enough and if it is prolonged enough for the small ( thenar ) muscles to the thumb in the heel of the hand to become wasted. The treatment is to release the transverse carpal ligament (a carpal tunnel decompression) usually under local anaesthetic. Surgical decompression should occur within 12 months of the onset of symptoms for the best results.
