This is no doubt a condition which many of you have had and about which others of you have at least heard.
Those in the former group will include many who have spent long hours computer keyboarding, but before you go running to your boss or your union, bear in mind that this syndrome dates back to the beginning of the 20th century, before the advent of computers. So you may have no case.
Now, the bones in your wrist joint proper are called carpal bones, those in your hand the metacarpals, and then of course you have your fingers, or phalanges. You’ll soon see why this condition was given this name.
The carpal tunnel is a narrow passageway – about as big around as you thumb – bounded by bones (that’s right, carpal bones) and ligaments. The tunnel is on the palm side of your wrist. It protects a main nerve, the median nerve, to your hand and nine tendons that bend your fingers. There’s no rocket science about medicine, you know. This nerve is called median because it is the middle of the three main nerves that serve your hand. With your palm faced forward the outer one in the radial nerve, and the inner one the ulnar nerve.
Pressure placed of the median nerve produces the numbness, pain, and, eventually hand weakness that is the carpal tunnel syndrome.
SIGNS AND SYMPTOMS
The syndrome typically starts gradually, with a vague aching in your wrist that can extend to your hand or forearm. Other common signs and symptoms include:
TINGLING OR NUMBNESS in your fingers or hand, especially your thumb, index, middle, and one half of your ring fingers, but not your little finger. This is your ulnar nerve’s baby. Now this is the typical anatomic picture, but none of us is 100% perfect, so there is sometimes a little overlap, in that some person’s thumb may not be involved, or it may seem as if the whole ring finger is involved. The sensation often occurs while driving, holding a phone or newspaper, or upon awakening. A lot of people try to “shake” out their hands to relieve their symptoms.
PAIN RADIATING OR EXTENDING from your wrist up your arm to your shoulder or down into your palms or fingers, particularly after forceful or repetitive use. Of course, this will occur on the front (palm) side of your forearm.
A SENSE OF WEAKNESS in your hands, and a tendency to drop objects.
A CONSTANT LOSS OF FEELING in some fingers in advanced cases.
The cause of carpal tunnel syndrome is pressure on the median nerve. It is a mixed nerve, meaning it carries sensation (sensory function), and carries signals to your muscles to allow them to move (motor function). Pressure on the nerve can stem from anything that reduces its space in the tunnel. Causes may include bone spurs, or the most common one, which is swelling or thickening of the synovium, the lining and lubricating layer of the tendons in your carpal tunnel.
Usually the exact cause of the swelling isn’t known, but a variety of factors can play a role:
OTHER HEALTH CONDITIONS. Rheumatoid arthritis, diabetes, menopause, thyroid disorder, especially a suboptimally functioning thyroid, acromegaly (gigantism), are among them. Pregnancy and an abnormal protein produced by your bone marrow, amyloid, are others. Don’t forget obesity.
REPETITIVE USE OR INJURY. Forceful or prolonged flexing and extending of the tendons in the hands and wrists can create the problem.
PHYSICAL CHARACTERISTICS. It may be that some people have a narrower than average tunnel, making pressure on the nerve easier to occur.
WHAT ARE SOME RISK FACTORS?
Overuse or strain in certain job tasks that require a combination of repetitive, forceful and awkward or stressed motion of your wrist or hand are thought to contribute to carpal tunnel syndrome. These include using power tools such as chippers, grinders, chainsaws or jackhammers.
Other risk factors have been mentioned under ‘other health conditions.’ In addition, women have a three times greater risk compared to men, especially after menopause (above). Middle-aged men get it more than younger men do.
Cigarette smoking causes worse symptoms and slower recovery from the syndrome than is the case with non-smokers. Interesting huh? How often have I warned against cigarette smoking, for any number of reasons? Here’s another one.
As always, the doctor will listen to your symptoms, your history, and can get a pretty good idea from this that you have carpal tunnel syndrome. Doctor will also test the feeling in your fingers and the strength of your hand muscles, because the syndrome can affect these. Pressure on the median nerve at the wrist, by tapping at the site (Tinnel’s sign), by bending the wrist or simply pressing the nerve, can bring on the symptoms in many people.
If you have signs and symptoms of the condition, we may recommend the following diagnostic tests:
ELECTROMYOGRAM. Electromyography measures the small electrical discharges produced in muscles. A thin- needle electrode is inserted into the muscle of interest. An instrument records its electrical activity at rest and as you contract the muscle. This test can help determine if muscle damage has occurred.
NERVE CONDITION STUDY. In a variation to electromyography, two electrodes are taped to your skin. A small shock is passed through the median nerve to see if electrical impulses are slowed in the tunnel.
TREATMENT OF CARPAL TUNNEL SYNDROME
Some persons with mild symptoms can find relief by resting their hand more frequently and applying cold packs to reduce occasional swelling. If these don’t help, other options include wrist splinting, medications and surgery.
Non-surgical therapy include:
* Splinting your wrist to keep it still while you sleep can help, more so if you’ve had only mild to moderate symptoms for less than a year.
* Non-steroid anti-inflammatory drugs (NSAID’S) may help relieve pain if you have an associated inflammatory condition, such as rheumatoid arthritis. Otherwise, they are unlikely to be of much use.
* Corticosteroids. An injection of one of these into the tunnel may relieve pain and, by decreasing inflammation, relieve pressure on the nerve. Taken by mouth, they are not as effective.
For persistent pain and numbness, surgery may be the best option. There are a few accepted techniques, but in all procedures, the ligament pressing on your nerve is cut. Some may even be done by endoscopy (similar to laparoscopy) where tiny incisions are made and the surgeon does his thing by finding his way via a tiny television camera. Cool, huh? In other cases, an incision is made in the palm of your hand over the carpal tunnel and releasing the nerve.
Reduce your force and relax your grip. For instance, if you use a cash register, hit the keys softly. For prolonged hand writing use a big pen with an oversized, soft grip adapter and fee-flowing ink, so that you don’t have to grip the pen tightly or press as hard on the paper.
Take frequent breaks, like every 15 to 20, minutes whenever you’re doing anything repetitive or forceful with your hands.
Watch your form. Try not to bend your wrist all the way up or down. If you use a keyboard, keep it at elbow height or slightly lower.
Keep your hands warm. You’re more likely to develop pain and stiffness if you work in cold environment. If you can’t control the temperature at work, put on fingerless gloves to keep your hands and wrists warm.
Improve your posture. It you don’t, your shoulders will roll forward, shortening your neck and shoulder muscles, compressing nerves in your neck. This can affect your wrists, fingers, and hands.
See you next week.
Dr. Emanuel, based in the Commonwealth of Dominica, has been an educator of medical professionals, in training and the public, for over 20 years.