What is Carpal Tunnel Syndrome?
Carpal tunnel syndrome is a condition where pressure on one of the main nerves to the hand (the Median nerve) leads to uncomfortable pins and needles sensations in the hand and, in the more severe cases, numbness, muscle wasting and weakness in the hand. The nerve passes through a tunnel in the wrist that has bony floor and sides but the roof of the tunnel is formed by a strong ligament (the transverse carpal ligament).
In the majority of cases there is no known cause but often runs in families. Pressure on the nerve in the carpal tunnel can occur because of;
- A narrow tunnel, thickening and tightening of the transverse carpal ligament across the tunnel with increasing age.
- Swelling of the soft-tissue contents of the tunnel (due to trauma or rheumatic inflammation of the tendons).
- Injury to the bones forming the margins of the tunnel.
- Generalised hormonal changes such as in pregnancy, the menopause or thyroid disorders.
There are also some other conditions such as diabetes (which can lead to nerve damage if poorly controlled) and cervical spondylosis (arthritis of the neck and compression of the nerves in the neck), which are associated with an increased occurrence of carpal tunnel syndrome.
- “Pins and needles” sensations in the hand at night. This may also occur with some manual activities during the day such as holding the phone and while the arm is elevated during daily activity.
- Numbness in part of the hand (supplied by the Median nerve) and this may be intermittent or, in the more severe cases, constant.
- Weakness of some of the muscles in the hand.
- Discomfort may extend beyond the hand into the forearm.
The diagnosis can be made from detailed clinical history and clinical examination without requiring special tests. However electrical tests (nerve conduction studies) are a useful investigation which can show slowing in the speed of conduction in the nerve at the site of compression if more than one location of nerve compression is suspected.
In some situations, such as in pregnancy, the condition may settle on its own once the hormonal changes have resolved after delivery of the baby.
- Wrist splint at night can improve night symptoms.
- Cortisone injection can give some relief in conditions where acute inflammation is the main cause, however it often has a temporary effect.
- Surgery involves relieving the pressure on the nerve by dividing the transverse carpal ligament and releasing the median nerve. This is usually carried out as a day case under local anaesthetic (you are awake for the procedure and a nurse accompany you during the procedure) and application of a tourniquet (to reduce the blood flow to the hand during the procedure).The incision is approximately 3 – 4 cm in length and is stitched at the end of the procedure. The procedure takes between 10-15 minutes. The hand is bandaged but the fingers are free to be used. Hand elevation in the first 24 – 48 hours after the operation is required to prevent swelling and throbbing.
Aftercare and follow up
Hand should be kept dry and clean until the stitches are removed. One week after the procedure the dressing are reduced by the practice nurse and the sutures are removed in the clinic 2 weeks after surgery. Normal daily activities and use of the hand is encouraged to avoid tendon and nerve adhesions immediately after surgery.
You should allow a period of approximately 2 weeks before driving and slightly longer if the procedure has been carried out on the left hand side as changing the gear and using the hand break may be difficult to perform. You will need to be collected from hospital after the operation.
Time off work
Your return to work will depend on your job. Light manual workers can return to duty in 2 – 3 weeks. Heavy manual workers should not exert maximal grip for 6 weeks.
Scar Desensitisation Exercises
- Circular motion massages to the scar, from the palm moving towards the wrist using a simple moisturising cream. This must be carried out for 10 minutes, at least 3 times a day.
- Rubbing the scar on different textured materials to improve skin sensitivity.
- Submerging the hand under the cold and warm water to improve the temperature sensitivity.
Revision carpal tunnel surgery
Following the initial carpal tunnel surgery, excessive scar tissue can lead to recurrence of carpal tunnel syndrome. The revision procedure requires longer incision, takes longer to perform and requires careful release of the median nerve from the scar tissues.This is carried out as a day case procedure under General Anaesthetic. Post operative care remains the same as the primary carpal tunnel surgery.