Carpal Tunnel Syndrome
Other popular names
Who does it affect?
It can occur in anyone but is more common in females over the age of 40 years.
Why does it happen?
In the majority of people, the cause is still unknown. However there are a number of conditions that that many people with carpal tunnel syndrome seem to have: pregnancy, thyroid disease, rheumatoid arthritis and wrist injuries. It is important to note that if you have one of these conditions it does not mean that you will definitely develop carpal tunnel syndrome, just you may be slightly more at risk.
Carpal tunnel syndrome occurs when the median nerve is compressed at the level of the wrist. The nerve and tendons that bend the fingers pass from the forearm into the hand through a narrow tunnel called the carpal tunnel. When there is a build up of pressure in this tunnel the nerve becomes squashed and causes symptoms of carpal tunnel syndrome.
Pins and needles in the thumb, index and middle fingers. This commonly occurs at night and the patient is often awakened from sleep and has to shake their hands to gain relief from these symptoms. Occasionally in severe cases, the muscles on the front of the palm next to the thumb can waste, causing hollowing. In such severe cases the thumb may become weak or clumsy.
Modified Phalen's test - Direct pressure over the carpal tunnel especially whilst bending the wrist forward, may reproduce the pins and needles in the thumb, index and middle fingers. Tinel's test - Tapping the nerve in the carpal tunnel may cause tingling in these fingers.
Nerve conduction studies can be used to record the speed of the nerve across the wrist joint. This can be compared to the other hand, or in cases where both hands are affected, compared to the normal population. The test takes about 20 minutes and is slightly uncomfortable.
The majority of these tests are not required as I can normally tell from experience whether you have this condition or not.
Simple painkillers (analgesia) and resting splints can offer help. Occasionally a steroid injection into the carpal tunnel will improve symptoms. However the majority of people who have symptoms have surgery. The last trimester of pregnancy is notorious for causing carpal tunnel syndrome, in such cases a splint of steroid injection can help. However on the birth of the baby the symptoms usually resolve over the coming months.
Most people who have carpal tunnel syndrome have surgery. The surgery is a day case procedure usually under local anaesthetic and takes about 10 minutes. A tourniquet is used; which is like a blood pressure cuff around the upper arm that prevents blood from obscuring the surgeons view. It is quite tight, but well tolerated for up to 20 minutes.
The surgery will be performed through a 4cm incision.
Local anaesthetic is given. Once numb, the skin is cut and then the underlying fat is retracted.
Care is taken not to injure sensory nerves to the palm. At the base of the incision is a thick band of tissue called the transverse carpal ligament. This structure needs to be released to allow the contents of the carpal tunnel to be decompressed.
Having released this ligament the contents of the carpal tunnel are inspected to ensure adequate release and no other conditions are present. The skin is sutured (stitched) with fine sutures and a bulky dressing is applied. If you are interested, as there is no bleeding, it is possible for your consultant to show you the sight of compression once the nerve is released.
You can go home soon after the operation. The anaesthetic will wear off after approximately 6 hours. Simple analgesia (pain killers) usually controls the pain and should be started before the anaesthetic has worn off. The hand should be elevated as much as possible for the first 5 days to prevent the hand and fingers swelling. Gently bend and straighten the fingers from day 1. The dressing is removed soon after your operation. The wound is cleaned and redressed with a simple dressing. Avoid forced gripping or lifting heavy objects for 2-3 weeks. The sutures are removed at about 10 days. You should notice an improvement in symptoms within a week but the final result may be realised at about 3 months.
Return to normal routine
Keep the wound dry until the stitches are out at 10 days.
Return to driving: The hand needs to have full control of the steering wheel and left hand the gear stick. You are advised to delay return to driving for at least 7 days or until the sutures are removed.
Return to work: Everyone has different work environments. Return to heavy manual labour should be prevented for approximately 4-6 weeks. Early return to heavy work may cause the tendons and nerve to scar into the released ligament. You will be advised of what you can do by your consultant.
Overall, over 95% are happy with the result. However complications can occur.
General risks (all less than 1%):
- Neuroma (nerve pain)
Reflex Sympathetic Dystrophy - RSD (<1% people suffer a reaction to surgery with painful stiff hands, which can occur with any hand surgery from a minor procedure to a complex reconstruction).
- Failure to completely resolve the symptoms. Affects about 5% people and may be due to chronic scarring of the nerve due to long duration of pre-operative pressure, symptoms suggesting this include muscle wasting and severe numbness
- Pillar pain (less than 2%) - a poorly understood complication with pain on the front of the wrist
- Numbness in the palm (less than 1%) - a small branch of the nerve passes across the skin incision, care must be taken too avoid injury to this.