Carpal Tunnel Syndrome

By: John Emmanuel Balido

Synonymous Term

Median Nerve Compression

What is Carpal Tunnel Syndrome?

is pressure on the median nerve, the nerve in the wrist that supplies feeling and movement to parts of the hand. It can lead to numbness, tingling, weakness, or muscle damage in the hand and fingers.

is a common disorder that is often associated with repetitive actions of the hands and wrists. Carpal tunnel syndrome is one type of repetitive stress injury and can lead to pain, numbness and sometimes disability of the hands

Carpal tunnel syndrome:

Carpal Tunnel Syndrome

Symptoms:

Numbness or tingling in the thumb and next two or three fingers of one or both hands

Numbness or tingling of the palm of the hand Pain extending to the elbow Pain in wrist or hand in one or both hands Problems with fine finger movements (coordination)

in one or both hands Weak grip or difficulty carrying bags (a common

complaint) Weakness in one or both hands

Risk Factor:

Some research suggests that carpal tunnel syndrome can result from overuse or strain in certain job tasks that require a combination of repetitive, forceful, and awkward or stressed motions of your hands and wrists. Examples of these include using power tools — such as chippers, grinders, chain saws or jackhammers — and heavy assembly line work, such as occurs in a meatpacking plant. Although repetitive computer use is commonly assumed to cause carpal tunnel syndrome, the scientific evidence for this association isn't definitive.

Risk Factor:

Sex- Women are three times as likely as men are to develop carpal tunnel syndrome.

Heredity- You may be significantly more likely to develop carpal tunnel syndrome if close relatives have had the condition. 

Risk Factor:

Certain health conditions- Conditions including some thyroid problems, diabetes, obesity and rheumatoid arthritis can increase your risk. People with end-stage kidney disease also are more likely to develop carpal tunnel syndrome. Women who are pregnant, taking oral contraceptives or going through menopause also are at increased risk, most likely due to hormonal changes. Fluid retention may be a cause of carpal tunnel syndrome during pregnancy.

Pathophysiology

The pathophysiologic basis for carpal tunnel syndrome is, in most instances, unknown. The carpal canal normally contains only the median nerve, the flexor tendons of the digits and the synovial lining of the tendons. The median nerve is compressed when the space available to it is decreased within the finite volume of the carpal canal. Conditions that cause synovial swelling are known to be associated with carpal tunnel syndrome. Pregnancy and rheumatoid arthritis are two well-known examples. Conditions like acromegaly and hypothyroidism may also be associated with carpal tunnel syndrome but these conditions are relatively rare, especially in the context of work-related symptoms of carpal tunnel syndrome.

Studies of biopsy specimens taken from the flexor tendon synovium at the time of surgery to perform a carpal tunnel release, show edema of this tissue even in patients not known to have a condition which is associated with swelling. This observation suggests that flexor tendon synovial edema may be the cause of median nerve compression but the immediate cause of the swelling in these cases is not known.

Pathophysiology

Intrinsic abnormalities of the median nerve itself may also act to lower the threshold for symptomatic compression. Pressures within the carpal canal that might not otherwise cause symptoms of carpal tunnel syndrome may do so if the nerve is rendered particularly sensitive to pressure by some other disease or condition. A common example of this is diabetes mellitus, which frequently affects peripheral nerve function. Peripheral nerves, including the median nerve, are a target of diabetes and in individuals with this condition, carpal tunnel syndrome may occur even where the pressure in the carpal canal is insufficient to cause these symptoms in a non-diabetic individual. In this sense, diabetes may be considered a pre-existing condition that predisposes the median nerve to symptoms of compression under circumstances where this might not otherwise occur. Other diffuse peripheral nerve diseases may also play a role in the development of symptoms of carpal tunnel syndrome but these are also very rare conditions which will usually be known to be present in an individual before symptoms of hand numbness are attributed to carpal tunnel syndrome.

A much less clear, but related concept is that of "double crush". In the double crush syndrome it is thought that sub-clinical compression of the median nerve at several points in its course between the spinal cord and the carpal tunnel, lowers the threshold for symptomatic compression at level of the carpal canal. While this idea fits in with some of what is known about peripheral nerve function, it is a largely unproven hypothesis. Furthermore, it can rarely be shown to be present in clinical cases of carpal tunnel syndrome and should seldom, if ever, play a role in the diagnosis or management of carpal tunnel syndrome.

Diagnostic Exam

Electromyogram. Electromyography measures the tiny electrical discharges produced in muscles. A thin-needle electrode is inserted into the muscles your doctor wants to study. An instrument records the electrical activity in your muscle at rest and as you contract the muscle. This test can help determine if muscle damage has occurred.

Diagnostic Exam:

Nerve conduction study. In a variation of 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 carpal tunnel.

Prevention

Reduce your force and relax your grip. Most people use more force than needed to perform many tasks involving their hands. If your work involves a cash register, for instance, hit the keys softly. For prolonged handwriting, use a big pen with an oversized, soft grip adapter and free-flowing ink. This way you won't have to grip the pen tightly or press as hard on the paper.•

Take frequent breaks. Give your hands and wrists a break by gently stretching and bending them periodically. Alternate tasks when possible. If you use equipment that vibrates or that requires you to exert a great amount of force, taking breaks is even more important.

Prevention

Watch your form.Avoid bending your wrist all the way up or down. A relaxed middle position is best. If you use a keyboard, keep it at elbow height or slightly lower.•

Improve your posture. Incorrect posture can cause your shoulders to roll forward. When your shoulders are in this position, your neck and shoulder muscles are shortened, compressing nerves in your neck. This can affect your wrists, fingers andhands.

Prevention

Keep your hands warm. You're more likely to develop hand pain and stiffness if you work in a cold environment. If you can't control the temperature at work, put on fingerless gloves that keep your hands and wrists warm

Nursing Intervention:

Administer mild analgesics as needed. Encourage the patient to express her concerns. Have her perform as much self-care, as her

immobility and pain allow. Provide her adequate time to perform these

activities at her own pace. Monitor the effectiveness of analgesics and other

forms of therapy used to relieve the patient’s discomfort.

Regularly assess the patient’s degree of physical mobility.

Nursing Intervention:

Teach the patient how to apply splint. Advise her not to make it too tight.

Show her how to remove splint to perform gentle range-of-motion exercises.

Advise the patient to occasionally exercise her hands in warm water.

If the patient is using a sling, tell her to move it several times a day to exercise her elbow and shoulder.

Review prescribed medication regimen. Emphasize that drug therapy may require 2 to 4 weeks before maximum effect is achieved.

Therapeutic and Pharmacologic Interventions:

Wrist splint in slight extension (cock-up splint) to relieve pressure aggravated by wrist flexion: worn at night, and during day if symptomatic.

Avoidance of flexion and twisting motion of the wrist. Work or activity modification to relieve repetitive strain. Non-steroidal anti-inflammatory drugs (NSAIDs) such as

ibuprofen 600 to 800 mg tid to relieve inflammation and pain. Corticosteroid injection into tendon sheath to relieve

inflammation.

Surgical Interventions:

Carpal tunnel release is a surgical procedure that cuts into the ligament that is pressing on the nerve. Surgery is successful most of the time, but it depends on how long the nerve compression has been occurring and its severity.

Carpal Tunnel Release

Carpal Tunnel Release

Endoscopic surgery

may allow faster functional recovery and less postoperative discomfort than traditional open release surgery. The surgeonmakes two incisions (about ½" each) in the wrist and palm, inserts a cameraattached to a tube, observes the tissue on a screen, and cuts the carpal ligament(the tissue that holds joints together). This two-portal endoscopic surgery,generally performed under local anesthesia, is effective and minimizes scarringand scar tenderness, if any. One-portal endoscopic surgery for carpal tunnelsyndrome is also available.

Nursing Diagnosis:

Acute pain Risk for injury Activity intolerance