CARPAL TUNNEL SYNDROME

1. What is Carpal Tunnel Syndrome?

Carpal tunnel syndrome is a medical condition that results from pressure or pinching of a nerve as it goes by the wrist to the hand. The nerve (which is called the median nerve) provides for muscle action to the thumb and sensation in the thumb, index, long and one-half of the ring fingers. This nerve travels with the tendons or leaders that move the fingers through an oval canal in the wrist which is called the carpal tunnel. Bone surrounds this canal on three sides while the carpal ligament covers the palm side.

The most common cause is a thickening or swelling that occurs in the liners of the tendons that go through the canal with the nerve, and occasionally occurs in the lifters.

The symptoms associated with carpal tunnel syndrome are generally a numbness which may or may not be painful and which intermittently occurs in the thumb, index and long fingers. Occasionally numbness may be felt by the patient in the ring and small fingers, but the worst numbness is generally in the long and index fingers. The condition characteristically worsens at night. This results from a tendency for fluid to build up within the tendons which are not being moved during the sleeping hours. As the fluid accumulates in the tendons and the tendon liners, the pressure in the canal increases, decreasing the circulation to the nerve. The characteristic symptoms of tingling or numbness or sleepiness in the hand results. Occasionally when the nerve pressure occurs at the wrist, there may be associated sensations of pain and numbness up the forearm which can extend into the arm, shoulder and even into the neck. Generally the hand symptoms are the worst.

During the daytime, typical activities such as sewing, reading a newspaper, holding the telephone or driving positions the wrist in such a way that the symptoms frequently are worsened. Any repetitive or heavy use of the hands, including weight-training, which might tend to increase the irritation of the tendons may also aggravate it. For unknown reasons the condition has been associated with utilization of oral birth control pills and anabolic steroids. Generally these should be discontinued if the condition occurs. Remember, of course, that anabolic steroids are banned substances.

2. What Causes Carpal Tunnel Syndrome?

In the majority of instances, carpal tunnel syndrome occurs without known cause. A few disease conditions such as a low thyroid and rheumatoid arthritis produce excessive thickening of tendons and result in carpal tunnel syndrome. People with diabetes may be more susceptible to the condition because of nerve damage from the diabetes. The vast majority of patients, however, probably have a constitutional predisposition or an inborn predisposition to develop thickening of their tendon linings with heavy use. The condition is extremely common and perhaps occurs to some degree in one out of 10 patients in the population. Persons involved in heavy lifting or occupations requiring repetitive motions of the hands, fingers, and wrists, and may aggravate their condition at their work. In the majority of instances, this situation is purely an overuse of tendons occurring in certain job activities but there are persons prone to develop these overuse syndromes in their hands and other parts of their bodies. Weight training and lifting have been implicated in worsening some cases, but rarely as the primary cause.

3. What are the Dangers of Carpal Tunnel Syndrome?

As mentioned above, the condition is very common in the population and many people who have this problem will not require any treatment. They simply find it an occasional annoyance or inconvenience. If the nerve pressure increases, it may interfere with the patient's comfortable life and cause permanent damage to the nerve. When symptoms reach the point that a patient is awakened frequently at night or has almost constant numbness, a need is present for medical or surgical treatment. If advanced damage does occur to the nerve, it is probable that medical treatment may not result in correction of the numbness and that surgical treatment is required. Additionally, weakness of the muscle that pulls the thumb away from the palm may occur and not be recoverable. For this reason the physician utilizes tests to determine whether or not treatment is indicated.

4. What are the Clinical Findings and Tests that the

Physician Uses to Diagnose Carpal Tunnel Syndrome?

The history of the problem of carpal tunnel syndrome as described above is typical. In general the symptoms of nocturnal (or nighttime) numbness and tingling with certain positions of the wrist make the physician suspect carpal tunnel syndrome. There are other locations where nerve pressure can cause similar symptoms but there are some very useful tests which will localize the nerve pressure to the wrist. Specifically, the physician may position your wrist to cause aggravation of the nerve pressure or he may "tap" on the nerve at the level of the wrist. Tingling produced by this maneuver indicates that this is the probable location of pressure. A very specific laboratory test, an electromyogram, may be performed to confirm that nerve pressure is present at the wrist. In some patients this test will be done although it is not mandatory to establish the diagnosis in a classical clinical situation. A very sensitive test is a thermogram which also can determine the presence of nerve compression, and sometimes the severity.

5. What is an Electromyogram?

An electromyogram, usually done with a nerve conduction test,studies the ability of a nerve to transmit electrical impulses from the areas of sensation in your fingers and into the muscles. The test which is mildly uncomfortable usually confirms the diagnosis of carpal tunnel syndrome. It utilizes mild electrical impulses or stimuli of the nerves. During the test the speed of conduction of the nerve impulses is measured by electronic devices and, if it is slowed across the wrist, it is indicative of pressure at this level. The amount of slowing will usually give an indication of the severity of the nerve compression. Additionally the muscles are tested and stimulated to determine if the nerve fibers to the muscles are impaired or slowed.

As mentioned above, this test may tell your physician not only if the nerve pressure is present, but how severe it is. With the help of this information he may elect to select medical or surgical treatment. In a percentage of patients, nerve pressure may exist in the presence of a normal electrical test but if it is normal your physician has other methods of determining whether or not nerve pressure is likely to be present, i.e. the thermogram.

6. What is a thermogram?

Thermography is a non-invasive (painless and harmless) study of heat changes of skin dermatomes throughout the body. Thermography can be done either electronically or by liquid crystal. If done with the liquid crystal, using Flexi-Therm contact, we use a unique elastomeric thermally sensitive film that can be readily contoured to display the thermovascular patterns of the body.

7. What is the Treatment for Carpal Tunnel Syndrome?

Medical Treatment. Nonsteroidal anti-inflammatories frequently help the symptoms and sometimes actually help cure the problem. There are several available, but it may take a trial of several weeks to determine how much they may help. Much higher than usual doses of Vitamin B6, C, and E frequently help decrease the inflammation and/or swelling, but are usually prescribed only for a few months at a time since they potentially have side effects similar to the nonsteroidal anti-inflammatories (NSAIDs). These seem to help best if you completely avoid caffeine, and this includes coffee, tea, and any of the several caffeine-containing soft drinks.

Some physicians may prescribe use of a splint to be worn on the wrist at night to treat mild carpal tunnel syndrome. This will prevent the wrist from getting into the flexed position and may decrease the amount of numbness that occurs in the hand at night (it does not change the condition per se). One form of nonsurgical treatment for carpal tunnel syndrome is an injection of cortisone into the area of the tendon liners of the wrist. This procedure is associated with minimal discomfort and may provide both diagnostic and therapeutic information to your physician. If the changes are felt to be minor on the testing, it may prevent surgical consideration. Specifically a small amount of novocain and cortisone are injected into the liners of the tendon sheaths about the wrist. The medication has the effect of reducing the thickness of the tendon liners and may, therefore, relieve the nerve pressure. Response is quite variable. In a small number of cases with moderate nerve pressure, injection may produce a complete cure of the symptom complex and the nerve pressure. However; in the majority of cases it will produce a temporary relief lasting from several weeks to several months. If the injections fail to produce relief of symptoms on a permanent basis, surgery may be advised. If the injection does not help at all, it raises the suspicion that the nerve pressure may not be present at the wrist but in some other area. Patients with diabetes or peripheral nerve damage from other causes are much less likely to be helped by injections or cortisone. In cases of severe nerve compres sion, the injections are generally omitted in favor of a more direct and definitive surgical approach.

SURGICAL TREATMENT

The surgical procedure for carpal tunnel syndrome involves enlarging the canal through which the tendons and the nerve pass at the wrist. In most cases, the release can be done endoscopically through a one inch incision, which can allow more rapid return to weight-training, working, etc. It may occasionally be done through an incision approximately 4 inches (10 cm) long starting at the mid-portion of your palm up towards your elbow curving at the wrist crease to prevent scar contracture.

The deep ligament which forms the roof of the tunnel is divided. This separates allowing the canal to enlarge. At the time of surgery the nerve is inspected for evidence of compression. If the lining around the tendons is quite thick, it may be removed. While the lining may grow back, the increased size of the canal will generally prevent numbness from returning.

The surgery is most often done under block anesthesia which provides minimal discomfort for the patient and rapid recovery without the associated dangers and potentially significant side effects of general anesthesia. After the surgery is performed, the skin is closed with stitches and a dressing is applied to the palm and fingers to hold the wrist in a backward position. This dressing is sometimes removed at two to four days and replaced with a small half cast which maintains the wrist in the appropriate backward position for healing of the wounds.

At about 2 weeks following surgery, the splint is removed and the sutures are removed. The hand is then allowed to be used freely without the use of dressings but it is necessary to avoid strenuous heavy use of the hand for four to six weeks following surgery. At this time some patients are able to return to full work activities. Occasionally discomfort and soreness in the incision develops as the healing occurs and will take approximately three to four months to go away. The symptoms of numbness and tingling, however, are generally relieved immediately following surgery. Some discomfort and occasional tingling are expected to occur for three to four months. The presence of burning redness and tender lumps about the incision is common for the first three to four months following surgery but resolve spontaneously by that time. Most lifters are able to resume light training in 3-4 weeks after surgery.

8. How Painful is Carpal Tunnel Surgery?

Most patients undergoing carpal tunnel surgery feel better the night after surgery. Occasionally mild oral narcotic pain medications are necessary but many people require nothing other than occasional aspirin. Fingers are free immediately after surgery for handling such items as coffee cups and light spoons but the wrist cannot bend. Therefore, there can be problems with personal hygiene for two weeks if both hands are done at the same time. With some help, even the patient who has had both hands operated on at the same time may carry on all the daily functional activities of living.

The decision to operate on both hands is generally left to the patient. If the condition occurs in both hands and is severe, it is probably wisest to proceed with decompression of the nerve on both sides. In most patients the condition is severe on one side and either non-existent or mild on the other. In these cases generally the more involved side only is done. Having the condition on one side does not necessarily mean that it will become severe on the other side although this is commonly the case.

9. When Can I Return to Work and Will I Return to Normal?

As mentioned previously, patients doing heavy work activities are not allowed to return to these activities until six weeks following surgery. At this time their incisions will be well healed but they may still be sore and there will be some aching and swelling in the hands. In these instances the patients are allowed to return to light work as no damage will be done to their hands by using them, but is may be three to four months before they feel quite comfortable and it may be a year before the hands feel totally normal. If the condition is occupationally aggravated or caused, a permanent impairment of 5 percent of the hand and wrist is a standard impairment rating for this problem. The patient may be advised not to return to the aggravating employment.

In general this procedure is 95 percent successful in relieving compression and relieving symptoms caused by nerve pressure at the wrist. In a very small percentage of cases there is a recurrence but this is probably less than 5 percent of the time.

NOTE

During the first three to four months following surgery, there commonly is a development of a firm and modular ridge on either side of the incision. This may be associated with a sensation of burning or heat and occasional tingling- shooting to the fingers with stretching of the incision. This is a normal response as the scar tissue forms at the site of surgery. With use of local massage of this tissue it generally resolves in three to four months as the scar underneath matures and softens as does the skin scar itself. In approximately two years in most patients the scar is nearly invisible although approximately 10 percent of patients may develop stretching and separating of their scars because of the nature and elasticity of their tissue.

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