Carpal Tunnel Syndrome

Carpal tunnel syndrome

What is Carpal Tunnel Syndrome?

Carpal Tunnel Syndrome (CTS for short) is the name given to a sensation of numbness, weakness, tingling and general discomfort in the area of the wrist and hand.

What causes it?

CTS is caused by compression of a special nerve at the wrist called the median nerve. This nerve runs through a confined space known as the carpal tunnel. The floor of the tunnel is formed by the wrist bones and the roof of the tunnel is formed by a tight band of tissue that runs across the palmar surface of the forearm.

'The median nerve is compressed at the wrist resulting in disruption of electrical impulses through the nerve'.

The median nerve conducts sensation from the palm side of the thumb and fingers excluding the little finger and half of the ring finger. The median nerve also carries impulses to small muscles in the hand. If the pressure in the carpal tunnel builds up the median nerve is compressed, giving rise to Carpal Tunnel Syndrome.

The main cause of CTS is swelling due to repetitive motion or overuse of the wrist and fingers. It can also be a feature of pregnancy, particularly in women who suffer from generalised swelling of the hands and feet throughout their pregnancy.

Diseases such as rheumatoid arthritis, sarcoidosis, diabetes and hypothyroidism can also give rise to CTS.

What are the symptoms?

CTS usually happens gradually, with a dull ache in the wrist which eventually extends into the hand and forearm. Often, a person with CTS will wake up in the middle of the night with pain and numbness in the hand and will need to shake or massage the whole hand and wrist to restore normal feeling. Some people complain of weaker handgrip resulting in letting things fall.

For people who engage in activities, which are repetitive, the pain and numbness may return during the day. If left untreated, Carpal Tunnel Syndrome may result in progressive and permanent weakness and numbness in the hand.

How is it diagnosed?

A diagnosis of CTS is based on a combination of symptoms and physical signs. Referral to a neurologist may be necessary for electrical testing of the median nerve. Abnormalities are detected in approximately 95% of people who suffer from CTS.

How is it treated?

For mild cases of CTS anti-inflammatory medication can be used for a short time to relieve pain and inflammation. Some people obtain considerable relief from splinting the wrists at night.

If an underlying disease causes CTS, then the first form of treatment is to tackle the underlying cause. Reducing salt intake and losing weight may also be helpful.

It is possible to inject a small dose of steroid into the carpal tunnel and this can be very effective in reducing swelling in the tunnel.

For severe cases of CTS, where there is considerably reduced sensation and pain, surgery may be considered. This form of surgery is called Carpal Tunnel Release and involves the severing of the band of tissue that overlies the median nerve. It is only ever considered when there has been no improvement in symptoms after a reasonable trial of conventional treatment.

Can it be prevented?

Repetitive use of the hand with the wrist in a bent position must be avoided. Frequent changes of activity, with breaks of 5 minutes every hour, will help to prevent over-use of the wrist. Certain flexibility exercises may also be beneficial.

The incidence of Carpal Tunnel Syndrome has increased with the advent of computerisation. This is partly due to over-using of the wrist and fingers, which perform repetitive tasks, all day, and every day. All those working at computers should ensure that their wrists are well supported while they work.

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