Carpal Tunnel Syndrome and Median Nerve Lesions

Carpal tunnel syndrome (CTS) is by far the most common cause of median nerve damage. The carpal tunnel is an anatomical compartment of the hand; it is bounded on three sides by carpal bones which form an arch, and on the palmar side by the transverse carpal ligament. Pathogenesis CTS results from compromise of median nerve function at the wrist, caused by increased pressure in the carpal tunnel, an anatomical compartment bounded by the bones of the carpus and the flexor retinaculum. Although the ends of the tunnel are in free communication with the surrounding tissues, tissue pressure in the tunnel is much higher in patients with CTS than in patients with normal wrists. Severe symptoms are occasionally associated with weakness and wasting. If axonal injury occurs secondary to prolonged ischaemia, the nerve dysfunction may become irreversible. Rarely, compression of more proximal parts of the nerve can occur at the forearm or elbow. The two significant conditions are pronator teres syndrome and anterior interosseous syndrome. Aetiology The incidence of CTS peaks in the late 50s, particularly in women, and the late 70s, when the sex ratio is more equal. CTS is more common in people who are obese and it often runs in families. The role of occupational and recreational hand use in causation remains controversial. [1] There is also a theory that patients who use their hands and wrists a lot are simply more aware of the symptoms. Genetic Square-shaped wrist. Short stature. Family history. Hereditary neuropathy. Secondary causes Post-Colles' fracture. Flexion/extension injury of the wrist.