CARPAL TUNNEL SYNDROME - Full extract 

Doris is a busy grandmother in her mid-50s. Since her daughter's marriage break-up, she has been even busier. Several weeks ago, she came into the surgery complaining of pins-and-needles in her right hand.

"I've been waking up every night with numbness in my hand," she said. "I have to sit on the edge of the bed and shake my hand to get some feeling back into it." Apparently she has been having milder symptoms in her left hand, as well as odd pains in both forearms.

There had been no recent falls or injury to the wrist. Doris had put down her symptoms to extra ironing and constantly picking up her young grandchildren.

When I examined her, I could find no abnormality at all. The sensation and muscle movements in the hand were normal. There were no elbow or shoulder problems, and her neck had a full range of movement. A full general examination also proved normal.

I explained to Doris that she probably had carpal tunnel syndrome. We discussed how the condition is thought to occur and then arranged for her to see a consultant surgeon for an opinion.

Various treatment options were discussed. It was decided that she initially have a cortisone injection in the front of her wrist and rest her arm in a splint at night. She is due to see the specialist again shortly. She understands that if her symptoms don't improve considerably, a small operation may be necessary to give permanent relief.

The median nerve is one of the main nerves in the arm. Branches of the nerve supply several muscles in the forearm and hand. It also carries back sensory impulses from the skin on the front of the outer palm and fingers.

Along with tendons, blood vessels and other structures, the nerve passes under a bridge formed by a thick strap of fibrous tissue that extends between bones on either side of the wrist. Because the nerve is fairly superficial at this point, any undue swelling in the area can compress it. This is called carpal tunnel syndrome. There may be numbness or pins-and-needles in the palm and fingers and the person may also experience pain. In chronic, severe cases, weakness and wasting of certain small muscles in the hand may also occur.

Although it is difficult to get precise figures about the incidence of carpal tunnel syndrome, we do know that it is fairly common. Anything that causes swelling of the wrist may cause it, for instance arthritis, fractures around the wrist and other injuries. It may also occur in people doing heavy repetitive manual work, especially if there is swelling in the tendon sheaths around the wrist.

Any condition where there is generalised fluid retention may also cause the symptoms, for instance pregnancy, heart failure and even an underactive thyroid gland. It is seen more frequently in middle-aged and older women, probably because of a tendency to retain fluid. During the day, fluid may accumulate in the legs, causing puffy ankles and then at night, some of this fluid finds its way back into the circulation and is redistributed. A very slight swelling of the wrists can occur, which can put pressure on the nerve, resulting in pins and needles in the hands.

The diagnosis of carpal tunnel syndrome can often be made on the patient's history, alone. Usually there is little to find, even on a careful examination. Arthritis in the neck with narrowing of the disc space and pinching of nerves as they leave the spinal cord can sometimes cause similar symptoms. Tennis elbow may also cause forearm discomfort, but usually pain and tenderness around the elbow are the main features. General medical problems and more serious spinal conditions also need to be considered but can usually be readily distinguished from carpal tunnel syndrome.

If there is any doubt about the diagnosis a test called a nerve conduction study can be arranged. Performed by a neurologist, it measures the speed of impulses downs the nerve into the palm of the hand. A definite hold-up in nerve conduction at the wrist indicates carpal tunnel syndrome.
Treatment depends on the severity and the duration of the symptoms as well as the age and general health of the person. Any underlying problems like arthritis or fluid retention have to be treated. If the symptoms are mild and fairly recent, a cortisone injection around the nerve and the use of a splint at night may provide effective relief.

In more severe or persistent cases, an operation may be necessary. This involves making an incision just beyond the front of the wrist and dividing the strap of fibrous tissue that is compressing the nerve. It is usually a straight-forward procedure that will fix the problem for good.

These days, an alternative technique using an operating telescope is increasingly used. Although not suitable for every case, it has the advantage of smaller incisions and a quicker recovery time.

Health Tip:
* Although numbness of one or both hands is a common symptom, it should always be carefully checked. Ask your doctor for advice.

Dr. Andrew Pattison: Common Consultations
North East Valley Division General Practice, Melbourne, Australia.   Disclaimer
  - Last modified: August 18, 2001