CARPAL TUNNEL SYNDROME

WHAT IS CARPAL TUNNEL SYNDROME?

Median nerve as it passes through the carpal tunnel
Carpal tunnel syndrome is where the nerve that runs through the wrist to the hand is compressed. This nerve is called the median nerve. It supplies the sensation to part of hand and impulses to drive some of muscles in the hand. The nerve runs under a ligament called the flexor retinaculum. This ligament binds the bones of the wrist (carpal bones) together and with them forms a tunnel.
Median nerve as it passes through the carpal tunnel

 

WHAT ARE THE COMMON SYMPTOMS?

  • Numbness in the fingers.

  • Pain in the fingers.
  • Weakness in some functions of the hand.
  • Symptoms worse at night.
  • Symptoms worse when the wrist is held at certain positions such as when using a computer or driving.
Causes carpal tunnel syndrome: swelling of the flexor tendon sheath of hand
This syndrome occurs due to compression injury of the median nerve. It is common in middle-aged women, although men can be seen, is much rarer. Sometimes it occurs without apparent cause, but may be associated with various rheumatic diseases, pregnancy and even some jobs that use a lot of hands at work (especially in those in which they hit frequently with the palm of your hand!).

Causes carpal tunnel syndrome: swelling of the flexor tendon sheath of hand

 

The symptoms are pain or numbness or cramping in the thumb, index and middle fingers of the hand, which typically is higher at night and especially at dawn, to the point that in some cases wakes the patient up. In advanced cases there is marked atrophy of the intrinsic muscles of the hands, especially those of the thenar (pound of muscle at the base of the thumb). In very advanced cases may even be deformity of the fingers.

In red the area of numbness and sensory loss in the carpal tunnel syndrome
Thenar atrophy in carpal tunnel syndrome
In red the area of numbness and sensory loss in the carpal tunnel syndrome

Thenar atrophy in carpal tunnel syndrome

WHAT CAUSES IT?

  • Arthritis of the wrist bones.

  • Thickening of the ligament over the nerve.
  • Hormone disorders such as acromegaly or diabetes.
  • Often there is no specific cause.

WHAT YOU NEED TO TELL THE DOCTOR BEFORE SURGERY?

  • If you have bleeding disorders.

  • Any health problems.
  • If you are taking blood thinning agents (e.g. Warfarin/aspirin/anti-inflammatory agents).
  • Drugs or other allergies.

WHAT ARE THE REASONS FOR HAVING AN OPERATION?

The commonest reason is that the symptoms in your hand/s have been causing significant discomfort or that you have been getting worse. Usually non operative therapy has failed.

HOW DO YOU DIAGNOSE CARPAL TUNNEL SYNDROME?

Your local doctor will usually make the diagnosis based on the symptoms that you are complaining of. He/she may send you for special electrical tests on the nerves in your arm called electromyography. If the nerve is affected then it takes longer for the impulses to cross the wrist and they are dampened as they cross. The test will confirm the diagnosis. Some people will have symptoms in both hands but one is usually worse than the other.

WHAT OPERATION IS PERFORMED?

The operation is called a Carpal Tunnel Decompression. It can either be performed under a local or general anaesthetic. You may be admitted as a day patient and go home after the operation or be admitted the day before. You may be admitted as a day patient and go home after the operation or be admitted the day before.

Regardless of the type of anaesthetic, you will not be able to eat or drink from midnight before the operation.

HOW IS THE OPERATION PERFORMED?

The surgical procedure is carried out through a small incision in the wrist, under local or general anesthesia and usually lasts about 10 to 15 minutes. If it is under local then this will be injected into the wound at this time (a sedative is given by the anaesthetist to help the operation pass). If it will be under general anaesthesia, you will go off to sleep after this. The median nerve is located and released throughout its way through the carpal tunnel stoping its compression. This is achieved by cutting a ligament that passes over the nerve and that in these patients is usually very hard and thickened. The size of the incision varies according to the surgeons. If endoscopy is used the size of the incision can be reduced and both hands can made in a single surgical procedure.

Incision for open approach in carpal tunnel syndrome release
Section of the anterior carpal ligament to release the median nerve
 
Incision for open approach in carpal tunnel syndrome release

Section of the anterior carpal ligament to release the median nerve
Median nerve in the background after complete section of the anterior carpal ligament
Surgical picture after complete section of the anterior carpal ligament
Stitched surgical wound after open carpal tunel release
Median nerve in the background after complete section of the anterior carpal ligament

Surgical picture after complete section of the anterior carpal ligament

Stitched surgical wound after open carpal tunel release
Endoscopic approach in carpal tunel release
Incisions in bilateral endoscopic approach for decompression of carpal tunnel syndrome
Endoscopic approach in carpal tunel release
Incisions in bilateral endoscopic approach for decompression of carpal tunnel syndrome

WHAT HAPPENS NEXT?

You will wake up in recovery and after about one hour you will be transferred to the ward. The nursing staff will be continually checking your pulse/blood pressure/limb strengths and sensation looking for any changes. You will probably only need oral analgesia. We will encourage you to keep your hand elevated. Most people will be able to go home the same day.

It is important that someone drives you home afterwards.

WHAT YOU SHOULD NOTIFY YOUR DOCTOR OF AFTER SURGERY

  • Increasing pain in the wound/wrist.

  • Fever.
  • Swelling or infection in the wound.

WHAT YOU SHOULD NOTIFY YOUR DOCTOR OF AFTER SURGERY

  • Increasing pain in the wound/wrist.

  • Fever.
  • Swelling or infection in the wound.
  • Increasing or new onset of weakness or numbness in the hand or fingers.

WHAT HAPPENS WHEN YOU GO HOME?

  • The covering bandage can be removed the next day. The old dressing should be changes daily from the second day or if gets wet.

  • You will have an early follow-up appointment to have your wound reviewed.
  • You are encouraged to try to keep the hand elevated and to use it as much as possible.
  • You must not lift anything heavy with the hand until told you can do so by your surgeon.
  • Sometimes you will need hand Physiotherapy.
  • It is important to keep the hand dry.
  • Your doctor will discuss driving and return to work with you.
Sling after carpal tunnel release
After the surgical procedure it is recommended to keep the arm raised, using a handkerchief or a sling, to prevent bleeding and swelling. It is also very important not to flex the wrist, but if you move a lot of fingers, including thumb. When you pass the effects of anesthesia can disturb the wound, but is usually enough with the usual analgesics.

WHAT ARE THE MOST COMMON RISKS INVOLVED IN THIS SURGICAL PROCEDURE?

  • Infection (treated with antibiotics).

  • Post-operative blood clot requiring drainage.
  • Nerve damage.
  • Wrist pain.
  • Scar in wound area.
  • Failure of symptoms to improve.

WILL YOUR SYMPTOMS GET BETTER?

In the great majority of cases YES, but if the nerve is badly damaged then recovery may be slow or not al all.

How can I get assistance?