Carpal tunnel syndrome

What is it?

Carpal Tunnel Syndrome (CTS) comprises a group of symptoms caused by pressure on the median nerve. This occurs at the level of the wrist as it passes through the carpal tunnel to supply the muscles of the hand. 

Why does it occur?

The direct cause behind the nerve being squashed as it passes within the wrist is unknown. A multitude of conditions are linked but don’t guarantee the development of carpal tunnel syndrome. These include pregnancy, rheumatoid arthritis, thyroid diseases and diabetes. Trauma to the wrist through fracture or repetitive strain may also precipitate symptoms. 

What are the symptoms?

This can include tingling or pain in the affected hand and fingers. It starts gradually but can progress to numbness and wasting of the muscles in the palm of the hand that are supplied by the median nerve. Patients typically suffer with their symptoms at night or after certain repetitive movements such as typing. You may find relief through shaking the hand or holding it over the side of the bed at night.

How is it diagnosed?

Your clinician will usually be able to establish whether you are suffering from carpal tunnel after taking a history and examining your hand and wrist. However, in some patients the symptoms are equivocal and nerve conduction studies (NCS) are needed.  This test measures how quickly your nerves relay information up and down your arm. This will be reduced in carpal tunnel syndrome. 

How is it treated?

1.    Non-surgical treatment

Those suffering at night often find relief in using a removable splint – this keeps the wrist straight whilst you sleep avoiding compression of the nerve. Steroid injections have been beneficial in those patient’s suffering with nerve compression as a result of tissue inflammation within the carpal tunnel.  The injected hydrocortisone is a strong local anti-inflammatory medication, acting to reduce swelling and subsequently pressure on the nerve. This is particularly useful in transient CTS which sometimes develops during pregnancy.

2.    Surgical treatment

This involves a small operation under local anaesthetic which acts to free up the nerve as it passes into the hand. Following the procedure your night tingling and pain should settle quickly but numbness in the fingers may take weeks or months to disappear depending on the severity of your CTS.