Carpal Tunnel Syndrome

Carpal tunnel syndrome is a painful condition of the hand and arm, characterized by numbness, tingling, weakness, and other symptoms due to compression of the median nerve in the wrist.

The syndrome occurs due to a variety of contributing factors, such as the anatomy of one’s wrist, certain underlying health problems, and repeated patterns of hand use.

Located on the palm side of the wrist, the carpal tunnel is a space bound by bones and ligaments, which protects the median nerve. When the tissue around the median nerve swells and presses on it, carpal tunnel syndrome develops. It is not entirely known how the process leading to this disorder evolves and how the nerve conduction changes. Initially, the disorder is reversible, but over a period of time, the insulation may wear away and the nerve can become permanently damaged.

Proper treatment can resolve problems like tingling and numbness while restoring normal wrist and hand function.

The following have been observed in people with carpal tunnel syndrome:

• Tenosynovium, which is when the protective lining of tendons swells within the carpal tunnel, possibly due to build-up of synovial fluid under the lining.
• The band of fibrous tissue called the transverse ligament, which forms the roof over the median nerve, becomes thicker and broader.
• The swollen tendons and thickened ligament press on the median nerve fibers, which leads to compression and reduces blood flow and the supply of oxygen to the nerve, thus slowing down the transmission of nerve signals through the carpal tunnel.

Sometimes, the median nerve may become enlarged, which may cause carpal tunnel syndrome to develop. 

Symptoms of carpal tunnel syndrome appear gradually and may start as numbness or a tingling feeling.

The syndrome begins slowly with “on and off” numbness or tingling in the thumb and index and middle fingers, often associated with discomfort in the wrist and hand.

Initially, the symptoms may be more prominent during the night.

Common carpal tunnel syndrome symptoms include:

• Tingling or numbness: Tingling and numbness, especially in the thumb and index, middle, or ring fingers, are the typical initial signs of the syndrome. The sensation may radiate to the shoulder or forearm. This sensation often occurs while holding a steering wheel, phone, or newspaper. Many people need to "shake out" their hands to relieve their symptoms. Over time, the hand may become numb. The person may also lose the ability to feel heat and cold.
• Weakness: Often, weakness in the hand could result in a tendency to drop objects. It also weakens your grip.
• Feeling of swelling: Even though there is no swelling visible, the patient may feel like the hands are swollen, which is an important indicator of severe CTS.

These symptoms may occur when the person is at rest at night or when the hands are being used. Symptoms may occur outside work, too.

Consult a doctor if any signs or symptoms are bothersome for a prolonged time and interfere with one’s normal activities and sleep. If left untreated, it may lead to permanent nerve and muscle damage.

Carpal tunnel syndrome is caused by repetitive stress, physical injury, or a medical condition. It is an inflammatory disorder. It is very difficult to know the exact cause of this syndrome, since no tests are available to identify its precise cause. The actual biological mechanism that causes carpal tunnel syndrome is not yet known, except in patients with some underlying medical condition.

Some studies have suggested that most cases are associated with a workplace factor, but as such, there is no strong evidence to show the cause-and-effect relationship. Many studies suggest this syndrome is primarily associated with conditions like diabetes, osteoarthritis, hypothyroidism, and rheumatoid arthritis. Also, people with genetic or environmental risk factors, such as obesity, smoking, alcohol abuse, or significant mental stress, are at a higher risk. A genetic component due to CTS running in families could also be a cause. Repetitive hand or wrist work by people susceptible to carpal tunnel syndrome could also increase the risk of nerve damage in the hand.

Carpal tunnel syndrome can result when the median nerve is irritated or compressed, irrespective of the cause. A wrist fracture can lead to carpal tunnel syndrome, as it narrows and irritates the nerve.

Swelling and inflammation from rheumatoid arthritis could also be a cause. The median nerve runs from the forearm through a tunnel in the wrist (the carpal tunnel) to the hand. It provides nerve supply to the palm side of the thumb and fingers (except the little finger).

The motor function of the median nerve allows for the movement of muscles around the base of the thumb. Often, no factor can be singled out as a cause for the syndrome; rather, a combination of factors contributes to the condition.

When you visit the doctor complaining of the signs and symptoms, the doctor may carry out one or more of the following tests to make a diagnosis of carpal tunnel syndrome:

• The doctor will first carry out visual and manual inspections of your hand to check for any abnormalities, as well as evaluate the wrist’s range of motion. Wrist extension is evaluated by placing the palms of the hands together. Placing the backs of the hands together tests wrist flexion. Abnormalities in the range of motion of the wrist can be seen in people who had prior wrist injuries or wrist arthritis. Sensation over the hand can be checked for any abnormalities by using a soft touch, pin prick, or two-pint discrimination. The strength of the fingers and hands can be checked as well.
• History of symptoms: Often, the characteristic signs and symptoms direct the diagnosis of carpal tunnel syndrome. For example, any problem involving the little finger can rule out carpal tunnel syndrome, because the median nerve doesn't supply the little finger. Likewise, weakness and numbness that occur while holding a phone or newspaper, gripping a steering wheel, or waking up during the night are characteristic of carpal tunnel syndrome.
• Physical examination: The doctor may ask how your fingers feel and how strong your grip is. Symptoms may surface while bending the wrist, simply pressing on the nerve, or any activity that puts pressure on the median nerve. Other causes of wrist pain like arthritis can be ruled out by taking an X-ray of the affected wrist.
• Physical tests include:
  • Phalen’s sign: Hold the elbows at shoulder level. With your wrist bent at 90 degrees, place the backs of your hands together and hold for 60 seconds. This will increase the pressure of the median nerve. If this test worsens or reproduces the symptoms of carpal tunnel syndrome, it indicates you may have it.
  • Tinel sign: Have someone hold your wrist and tap on the palm side of it. If it produces tingling in the thumb or index or middle fingers, it is a sign of an irritable nerve. This may indicate carpal tunnel syndrome.
• Electromyogram: Electromyography measures the tiny electrical discharges produced in the muscles when at rest or in motion. It helps evaluate muscle response when the nerve is stimulated and may rule out other conditions.
• Nerve conduction study: This test helps determine if nerve conduction in the carpal tunnel is affected, as the syndrome can alter electrical impulses in the carpal tunnel. The nerve impulse travels more slowly across the wrist than is normal in people with this syndrome. In people with advanced cases, these measurements of electrical activity in the muscles of the hand indicate signs of muscle deterioration.

You may be recommended to see a neurologist or a neurosurgeon if additional treatment is required.

The treatment of carpal tunnel syndrome should begin as early as possible to minimize discomfort and prevent further complications. Simple techniques like resting your hand regularly during work, applying ice packs on the affected areas, and avoiding triggers may help.

If symptoms persist and do not go away with these techniques, you may need treatments such as wrist splinting, medications, or surgery. Mild to moderate symptoms lasting less than ten months usually resolve with splinting and simple techniques.

Non-surgical methods are effective if symptoms are mild, some of which include:

• Wrist splinting: Nocturnal splinting immobilizes the wrist during sleep and can help relieve tingling and numbness. It may be a good option for pregnant women.
• Nonsteroidal anti-inflammatory drugs (NSAIDs): NSAIDs, such as ibuprofen, provide short-term relief from pain, although these drugs are not found to improve carpal tunnel syndrome.
• Corticosteroids: Injecting the tunnel with a corticosteroid, such as cortisone, decreases inflammation and swelling, which releases pressure on the median nerve. Injectable corticosteroids are found to be more effective than oral corticosteroids for treating carpal tunnel syndrome. If rheumatoid arthritis is the cause of the syndrome, treating the arthritis may help.

Surgery is reserved for cases that persist and do not improve with non-surgical methods. The goal of carpal tunnel surgery is to relieve pressure on the median nerve by cutting the ligament that presses it. Talk to your doctor to weigh the risks and benefits of surgery. Surgery has risks like incomplete release of the ligament, infections, scar formation, and nerve or vascular injuries.

The two surgery techniques are:

• Endoscopic surgery: An endoscope (a telescope-like device with a tiny camera attached to it) helps the surgeon see inside the carpal tunnel and cut the ligament.
• Open surgery: A larger incision is made in the palm of the hand over the carpal tunnel, and the ligament is cut to free the nerve. You may use your hand after surgery and return to normalcy gradually. But you are not allowed to use the hand for work that requires extreme force. It may take a few months for any soreness or weakness to go away. In very severe cases, the symptoms never go away completely, even after surgery.

Note that both techniques provide almost the same level of resolution. Talk to your doctor about which would work best for you.

You cannot prevent carpal tunnel syndrome, but minimizing stress on your hands and wrists may help. There is no single way to prevent carpal tunnel syndrome, since many factors can contribute to it. Hence, treating any underlying medical condition is important. Risk factors that predispose a person to work-related CTS or any other trauma disorders should be minimized. A patient should learn to handle tools, adjust the work area, and perform tasks that are less stressful to the hands and wrists. Exercise programs to strengthen the fingers, hands, wrists , shoulders, forearm, and neck can be adopted to help prevent CTS.

You may try these precautions:

• Reduce your force and relax your grip: Use force only as required. Don’t overdo or overpower.
• Take frequent breaks: Stretch and bend your wrist at regular intervals.
• Watch your form: Don’t bend your wrist all the way up or down; a relaxed middle position is best. While using a keyboard, keep it at elbow height or slightly lower.
• Improve your posture: Incorrect posture that shortens the shoulder muscles can compress the nerves in the neck, which can affect your wrists, fingers, and hands.
• Keep your hands warm: Cold temperatures may cause hand pain and stiffness. Keep the work place warm. If you cannot, you can try fingerless gloves to keep your hands and wrists warm.

You can use alternative remedies to treat carpal tunnel syndrome after consulting your doctor.

Some alternative therapies that might work are:

• Yoga: Yoga postures that strengthen joints in the upper body may help reduce pain and improve grip strength.
• Hand therapy: Certain physical and occupational hand therapy techniques are shown to improve symptoms of carpal tunnel syndrome.
• Ultrasound therapy: High-intensity ultrasound that warms the carpal tunnel improves symptoms.

Lifestyle modifications are necessary in order to cope with carpal tunnel syndrome.

You may implement the following techniques to get temporary relief from the symptoms:

• Take frequent breaks from prolonged activities that involve your hands.
• Rotate your wrists and stretch your palms and fingers.
• Take a painkiller, such as aspirin, ibuprofen, or naproxen.
• Wear a wrist splint at night. Remember, the splint should not be too tight or too loose.
• Don’t sleep on your hands.
• If pain, numbness, or weakness recurs and persists, see your doctor.

The risk factors for carpal tunnel syndrome are:

• Anatomic factors: A wrist fracture or dislocation can create pressure on the median nerve. People with smaller carpal tunnels are also at an increased risk.
• Sex: Females are more likely to develop the syndrome due to having smaller carpal tunnels.
• Nerve-damaging conditions: Some chronic illnesses, such as diabetes, boost one’s chances of nerve damage, including damage to the median nerve.
• Inflammatory conditions: Illnesses such as rheumatoid arthritis may put pressure on the median nerve.
• Alterations in the balance of body fluids: Pregnant or menopausal women are more prone to the syndrome due to fluid retention, which increases the pressure within the carpal tunnel. Pregnancy-associated carpal tunnel symptoms generally subside on their own after pregnancy.
• Other medical conditions: Certain conditions like obesity, thyroid disorders, and kidney failure may increase your risk for carpal tunnel syndrome.
• Workplace factors: The association between computer use and carpal tunnel syndrome is under study, and to date, no clear association has been established.
• Diabetes: A common feature of diabetic neuropathy is CTS. It is one of the disease’s major complications. It causes decreased or distorted nerve function and affects sensation. Numbness, tingling, weakness, and a burning sensation that starts from the fingers and toes and moves up to the arms and legs are its symptoms. Up to 85% of people with type 1 diabetes develop carpal tunnel syndrome. It is related to the patient’s age and the length of time of diabetes.
• Autoimmune disease: These include rheumatoid arthritis, systemic lupus erythematosus, and thyroiditis, which can lead to hypothyroidism. In this, the body’s immune system attacks its own tissues. This causes inflammation and may affect the carpal tunnel. Studies have shown that a CTS patient with an autoimmune disease may require surgery, since their CTS may become more severe.
• Diseases that affect muscles and bones: Conditions that affect the muscles, joints, or bones in the hand, such as arthritis, gout, and others, may also cause changes and lead to CTS.
• Chronic kidney insufficiency: People with chronic kidney damage who are undergoing hemodialysis often experience build-up of beta2-microglobulin in the hand, which can result in CTS. Other medial conditions, such as Down’s syndrome, amyloidosis, acromegaly, and tumors on the median nerve, may also increase one’s susceptibility to CTS. Certain medications that affect the immune system and anticlotting drugs may also increase the risk.
• Injuries: If a bone is dislocated, it may narrow the carpal tunnel and put pressure on the median nerve.
• Hormonal changes: Fluctuations in hormones may cause fluid retention, which can cause CTS, especially during pregnancy.
• Genetic factors: Young people with carpal tunnel syndrome most likely have a genetic component involved; other genetic factors may include abnormalities in certain genes that regulate myelin.
• Age: Older people are at a higher risk; children rarely develop this syndrome.
• Women: The reason is unknown, but women are at a greater risk, since their carpal tunnel is smaller in size, and hormonal changes also play a major role in CTS. The chances also increase after delivering a baby and during menopause. Also, women are at a greater risk of developing autoimmune disorders significantly linked to CTS.
• Obesity and lack of fitness: This is a consistent risk factor for CTS.
• Specific workers: Computer users, typists, and musicians are at a higher risk.
• Physical characteristics: Square wrists, palm shape, and poor upper back strength make one more susceptible to CTS.
• Other factors: Cigarette smoking, poor nutrition, previous injuries, and stress can also increase the risk.