Carpal Tunnel Syndrome

Carpal tunnel syndrome is the most common trapped nerve problem. The wrist expert offers advice for anyone who suffers from trapped wrist nerves and details the causes, symptoms, diagnosis and treatment of the syndrome.


What is carpal tunnel syndrome?

Carpal tunnel syndrome is a condition in which the median nerve is compressed at the wrist within an anatomical structure called the carpal tunnel which is at the base of the palm. Inside the carpal tunnel are the median nerve and the flexor tendons to the fingers and thumbs. The walls of the tunnel are the wrist bones making up the floor of the tunnel and a ligament-like structure called the flexor retinaculum that is the roof. Carpal tunnel syndrome is caused predominantly by compression of the median nerve at the wrist because of overgrowth or oedema (swelling) of the synovial coverings around the flexor tendons. Pain is believed to be due to decreased oxygen to the nerve rather than direct physical damage of the nerve.

Who gets carpal tunnel syndrome?

Carpal tunnel syndrome is the most frequently encountered peripheral compressive neuropathy (trapped nerve problem). 10% of all people will suffer from carpal tunnel syndrome in their lifetime. Carpal tunnel syndrome is more prevalent in females than in males and common in middle-aged persons.

What are the symptoms of carpal tunnel syndrome?

Patients typically complain of an intermittent "pins-and-needles" paraesthesia in the median nerve distribution of the hand. Often the thumb, index and middle finger but all fingers may be affected. Pain is generally worse at night than during the day. Patients may awaken with a burning pain or tingling that may be relieved with shaking their hands. Pain may spread all the way up the forearm to the elbow and shoulder. Symptoms are most often in both hands, develop slowly, and progress.

What happens if I just leave well alone and don’t have this problem treated?

Early on in carpal tunnel syndrome, the nerve symptoms are reversible. If untreated, carpal tunnel syndrome can result in thumb muscle wasting, chronic hand weakness, and permanent numbness in the median nerve area of the hand. It can be very disabling.

Is it due to my work?

There was a great deal of debate in the 1980’s concerning the relationship between carpal tunnel syndrome and work with repetitive movements. This has not been clearly proven. There appears to be a relationship with the use of vibrating power tools.

What are the causes of carpal tunnel syndrome?

It can just come on without a recognisable cause. A wrist that has been fractured may have an altered shape of the carpal tunnel may develop carpal tunnel syndrome. Carpal tunnel syndrome is also related to a number of medical conditions such as diabetes, hypothyroidism, Acromegaly rheumatoid arthritis, gout, pseudo-gout. Compression of the median nerve from pregnancy or oral contraceptive-related oedema is common. There is also an association between being overweight and the presence of carpal tunnel syndrome.

How is the diagnosis made? How does the surgeon know I have carpal tunnel syndrome?

Patients often present with a history suggestive of carpal tunnel syndrome such as ‘pins and needles’ in the fingers, night pain and discomfort or a history of a related cause. On physical examination there may be decreased sensation in the thumb, index or middle finger or weakness of median nerve innervated thumb muscles. There are also special provocative tests for carpal tunnel syndrome. Phalen’s sign is bending of the wrist for 60 seconds which may elicit ‘pins and needles’ in the median nerve distribution. Tinel’s sign is the production of ‘pins and needles’ by tapping the underside of the wrist over the median nerve.

Are there tests to confirm the diagnosis?

Nerve conduction studies (NCV) and Electromyographic (EMG) are the investigations of choice for confirming the clinical diagnosis of carpal tunnel syndrome. One can evaluate the site and severity of the nerve compression. However patients with symptoms of carpal tunnel syndrome may have normal test results. Ultrasound scanning or magnetic resonance imaging (MRI) have been used to investigate carpal tunnel syndrome.

What is the non-operative treatment of carpal tunnel syndrome?

The mainstay of early treatment is rest, wrist immobilisation with a splint (in the neutral position) and non-steroidal anti-inflammatory drugs (NSAIDs).  Corticosteroid injections may be employed in mild cases to confirm the diagnosis, their benefit is usually temporary.

What is the surgery for carpal tunnel syndrome?

Definitive therapy consists of surgical release of the flexor retinaculum, the roof of the carpal tunnel.This is a carpal tunnel decompression. This is undertaken as a day-case and a small longitudinal incision is made over the underside of the wrist over the carpal tunnel. The nerve is thoroughly released and the skin is closed with stitches and then the wrist is bandaged with the fingers free.

What is the anaesthetic used for this surgery? Will I feel pain?

The surgery can be undertaken under local anaesthetic with or without sedation. It can also be undertaken under general anaesthetic.

What is the success rate with surgery?

Surgery for carpal tunnel syndrome has a long-term success rate of greater than 75%.

I think I have carpal tunnel syndrome where should I ask my GP to be referred?

Ideally to a ‘one-stop’ carpal tunnel syndrome clinics where you will be evaluated by a specialist hand surgeon and undergo nerve conduction studies and the diagnosis can be made immediately. Otherwise to a specialist hand surgeon or a rheumatologist with an interest in upper limb problems.

Who undertakes the surgery?

Ideally this should be a specialist hand surgeon.

What is the post-operative follow-up?

There is a padded bandage for a week, however the fingers are all free for activity. This bandage is then reduced and a smaller dressing applied. Stitches should spontaneously dissolve at approximately 2 weeks. Thereafter there is no dressing required. Some patients may require hand therapy after surgery due to swelling or mild stiffness.

What are the possible complications?

This is an extremely successful procedure with minimal complications. There are no internal stitches. Wound infection is exceedingly rare. Occasionally patients have some mild post-operative stiffness and swelling that requires some hand therapy. There may be a small amount of discomfort in the scar which resolves at approximately two months. In severe cases there may be a small amount of numbness that may persist in the fingertips.

For further information on the author of this article, Consultant Orthopaedic & Hand Surgeon, Mr Elliot Sorene, please click here.
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