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Carpal tunnel syndrome
Specialty	Neurology, orthopedic surgery

Carpal tunnel syndrome is a medical condition in which the median nerve is compressed at the wrist causing symptoms like tingling, pain, coldness, and sometimes weakness in parts of the hand. It is the best known of a class of disorders called repetitive strain injuries.

Anatomy

The median nerve runs through the carpal tunnel, a canal in the wrist that is surrounded by bone on three sides, and a fibrous sheath (the flexor retinaculum) on the other. In addition to the nerve, many of the hand's tendons pass through this canal. The median nerve can be compressed by swelling of the contents of the canal, by soft tissue swelling in and around the tunnel or even by direct pressure from part of a broken or dislocated bone. However, bone dislocations are a rare cause of carpal tunnel syndrome. Therefore, they need arm support to alleviate movement and the risk of pain as well.

Incidence

The syndrome is much more common in women than it is in men.

Symptoms

The first symptoms usually appear when trying to sleep. Symptoms range from a burning, tingling numbness in the fingers (especially the thumb and the index and middle fingers) to difficulty gripping, making a fist, or dropping things. Most early sufferers mistakenly blame the tingling numbness on their sleeping position, thinking their hands have had restricted circulation and are "falling asleep". If left untreated the symptoms often progress to intense pain which restricts hand functionality. It is known as a hidden disability, because people can do some things with their hands and appear to have normal hand function, but often live with severely restricted hand activity due to the pain.

Causes

Some cases of carpal tunnel syndrome are due to work-related cumulative trauma of the wrist. It is commonly caused by strain placed on the hand, for instance gripping and typing, which are usually performed repetitively in a person's occupation. The condition was first diagnosed in Australia in the 1980s when musicians started to use synthesizers heavily and people using these instruments started to get hand and wrist pain. The condition went mostly undiagnosed in the US until the mid 1990s when computers became more popular in the workplace.

There are a number of causes of carpal tunnel syndrome. They can be either traumatic, or non-traumatic.

Repetitive stress induced carpal tunnel strain is the leading cause of carpal tunnel syndrome in most industrialized countries. In the USA for instance, repetitive stress induced carpal tunnel syndrome is the biggest single contributing factor to lost time at work. This type of carpal tunnel syndrome results in billions of dollars of workers compensation claims every year.

Repetitive hand and wrist action often results in subcutaneous tissues becoming injured and swollen. These tissues include fascia, muscle, ligament, tendon, sheaths, retinaculum and peripheral nerve and blood vessels. In restricted passages of the body, swollen soft tissue can become compressed together creating intense pressure. Adjacent soft tissue can adhere together when compressed under these conditions over a prolonged period.

Trauma-based causes:

• Fractures of one of the arm bones, particularly a Colles' fracture.
• Dislocation of one of the carpal bones of the wrist.
• Strong blunt trauma to the wrist or lower forearm, incurred for example by using arm extremity to cushion a fall or protecting oneself from falling heavy objects.
• Hematoma forming inside the wrist, because of internal haemorrhaging.
• Deformities due to abnormal healing of old bone fractures.

Non-traumatic causes generally happen over a period of time, and are not triggered by one certain event. Examples include:

• Tenosynovitis, which is inflammation of the joint. Part of the process of inflammation is swelling, and this compresses the nerve.
• With pregnancy and hypothyroidism, fluid is retained in tissues, which swells the joint.
• Acromegaly, a disorder of growth hormones, compresses the nerve by the abnormal growth of bones around the hand and wrist.
• Tumours (though not necessarily cancer), such as a ganglion or a lipoma, can protrude into the carpal tunnel, reducing the amount of space.
• Diabetes, rheumatoid arthritis, and obesity tend to cause swelling, thus decreasing the amount of space in the carpal tunnel.
• Double crush syndrome, in which compression or irritation of the median nerve at the spine or in the upper back increases the sensitivity of the nerve to compression in the wrist.
• Idiopathic causes, which no one can explain, can also cause this disease.

Common activities that have been identified as contributing to repetitive stress induced carpal tunnel syndrome include:

• Computer keyboarding or typing
• Playing video games
• Playing a musical instrument
• Driving a vehicle, motorcycle or flying a plane
• Pushing a lawn mower (both the pressure and the vibration are to blame)
• Any activity where hand use is vigorous and routine could contribute (surgeons, dentists, possibly masturbation)

An exhaustive list can be found in the external links below

Often people suffering from carpal tunnel syndrome can have multiple contributing factors which are aggravated by vigorous hand activities and repetitive stress trauma to the hand.

Proper attention to ergonomic considerations can reduce or eliminate these kinds of injuries.

Diagnosis

There are two easy methods to test for carpal tunnel syndrome. One is squeezing or clenching the hand and noticing a lack of strength.

A second test, known as Phalen's maneuver, is performed by grabbing the fingers and pulling the hand back, towards the body, approaching but not reaching a 90 degree angle. If this position hurts, tingles or burns within the first 10 seconds then carpal tunnel syndrome exists. The quicker the pain starts, the more advanced the condition.

A classic, though less effective method, Tinel's sign, is a way to detect irritated nerves. It is performed by lightly banging (percussing) over the nerve to elicit a sensation of tingling or "pins and needles" in the distribution of the nerve. In a person with carpal tunnel syndrome where the median nerve is compressed at the wrist, Tinel's sign is often "positive" and causes tingling in the thumb, index, and middle fingers. Tinel's sign is sometimes referred to as "distal tingling on percussion" or DTP.

Treatment and Prevention

There has been much discussion as to the most effective treatment for CTS. There are five basic categories:

1. Wearing immobilizing braces or wrist splints
2. Having localized steroid injections
3. Soft Tissue Therapy
4. Prioritize activities and Ergonomics
5. Carpal Tunnel Release Surgery

Immobilizing braces

Rigid immobilizing braces and wrist splints can help some people, but they are limiting, unsightly and uncomfortable to wear. Over several weeks braces and splints often result in hand and forearm muscle atrophy. For this reason braces should not be worn continuously for more than a few days at a time. Instead many health professionals suggest that, for best results, one wear them at night, and if possible during the activity that causes stress on the wrists.

Localized Steroid Injections

Steroid injections can be quite effective for temporary relief from the symptoms and pain of CTS for a short time frame while a longterm strategy that fits with one's life style is developed. However, it is not a long-term solution. Ethical medical professionals would only resort to localized steroid injections for a short time until another acceptable treatment option could be identified.

Soft Tissue Therapy

Many people are turning to soft tissue therapy as a way to prevent pain and avoid sleep loss and work interruption. Soft tissue therapy can result from doing exercises, visits to chiropractors and using a new class of medical device which for many CTS sufferers offers relief from CTS pain and hand tingling in days. These are different from other over-the-counter CTS treatments and are not rigid immobilizing braces or wrist splints. Worn during sleep, soft tissue devices gently reshape soft tissue in and around the carpal tunnel and work to eliminate hand pain, numbness and sleep interruption.

One recommended stretching exercise is:

1. Sit in a chair.
2. Place the right elbow into your side, palm side of the hand facing upwards.
3. Using the left hand, push the right hand down by applying pressure to the four largest fingers.
4. Hold for two seconds.
5. Release the stretch by taking the pressure off the fingers and just letting the hand naturally come back.
6. Perform 10 repetitions, switch arm configuration and perform 10 more repetitions.

Prioritizing Hand Activities and Ergonomics

Using our hands is a defining characteristic of the human condition. While avoiding activities that cause repetitive stress is an option that can help avoid the pain, it causes people to curtail their careers, forfeit earnings and give up whole segments of their lives. Our self esteem as human beings and contributors at home, at work and at recreation is directly tied to the way we use our hands. Giving up activity is a poor option for most people.

More frequent rest can be useful if it can be orchestrated into one's schedule, but rest is not very practical in today's active work environment. It has been shown that taking multiple mini breaks during the stressful activity is more effective than taking occasional long breaks. There are two applications available that allow one to set up a proper breaking schedule by blocking input to the computer. The first to appear was a commercial solution called WorkPace, which was followed eventually by a free software alternative known as WorkRave. Both applications have recommended defaults, following the most effective average break configuration which is a 30 sec. pause every 3 to 5 minutes (the more severe the pain, the more often one should take this break). During this break it would be best to perform a stretching exercise or simply let one's arms dangle to the ground. Note that one will find these breaks very disruptive at first, but once adjusted to them, they will make a huge difference in carpal tunnel pain, possibly giving more stress reduction than all other treatments combined.

Changes in diet relate to providing the body with the nutrients it needs to reduce the inflammatory action of the carpal muscles in order to reduce pressure on the nerve, thus allowing it to heal, as well as providing nutrients needed to repair nerves. No specific vitamin or nutrient has been shown to have a noticeable anti-inflammatory effect, but taking a diverse multivitamin can have a noticeable effect on reducing inflammation in the body. Using an over-the-counter anti-inflammatory such as aspirin or ibuprofen is very effective as well. Pain relievers (ex: Tylenol) will only mask the pain and only an anti-inflamatory will give the carpal nerve time to heal. Certain vitamins and nutrients can also be taken to repair nerve damage, such as amino acids, vitamin B complex and hypercium (an extract of St John's wort). A more aggressive option is an injection of cortisone, to reduce swelling.

More pro-active ways to reducing the stress on the carpal tunnel involve adopting a more ergonomic work and life environment such as using an ergonomic keyboard (and perhaps switching from a QWERTY key layout to a more efficient Dvorak Simplified Keyboard layout). Studies have shown ergonomic keyboards reduce wrist stress by 30% or more and Dvorak reduces stress an additional 30%. It's also important that one's body be aligned properly with the keyboard. This is most easily accomplished by bending one's elbows to a 90 degree angle and making sure the keyboard is at the same height as the elbows. Also it is important not to put physical stress on the wrists by hanging the wrist on the edge of a desk, or exposing the wrists to strong vibrations (ex: manual lawn mowing). Position the computer monitor directly in front of your seat, so the neck is not twisted to either side when viewing the screen.

Excercises that relax and strengthen the muscles of the upper back can reduce the risk of a double crush of the median nerve. Spinal manipulations performed by an osteopath or chiropractor may be required to relieve compression of the nerve.

Carpal Tunnel Relief Surgery

Carpal tunnel syndrome begins with numbness and tingling in the hand and may involve aching in the hand, forearm or shoulder. It is a very common condition that is caused by a pinched nerve in the palm of the hand. The symptoms may occur intermittently during the daytime and sometimes occur at night and awaken one from sleep. It is not uncommon for the sufferer to think that the hands have "poor circulation" and shake the hands in an attempt to "restore circulation"

Doing nothing can possibly lead to irreversible damage. If you have CTS, the nerve that provides sensation to the hand and function to the thumb is being "pinched." After remaining in the pinched stage for a period of time, permanent injury to the nerve will result. There is no treatment that can fully restore hand function and sensation once permanent damage is sustained.

The hand surgeon will first examine your hands and review your symptoms. If you have something other than carpal tunnel syndrome, the doctor will suggest the appropriate treatment. If CTS is suspected, he will first prescribe non-operative treatment with splinting and anti-inflammatory drugs. A test conducted on the nerve will positively determine whether or not it is pinched and if you have carpal tunnel syndrome.

If all your symptoms go away with splinting and medication, then surgery will not be necessary. If not, then the "carpal tunnel release" surgery is recommended.

For over 50 years, the surgery to correct carpal tunnel syndrome has had a limited rate of success - full recovery after surgery is achieved in less than 60% of cases, painful and ugly scars are associated with the surgery. Downtime and rehabilitation can take up to three months resulting in a significant loss of earnings, and depression.

Then in 1991, the Brown Procedure Endoscopic Carpal Tunnel Release was patented by Dr. Michael G. Brown of Houston, Texas. The procedure is performed on an outpatient basis. No hospital stay is required. With the Brown Procedure, the recovery period is approximately 2 days. For the Brown Procedure, an endoscope is used in two small cuts in the hand, which require no stitching afterwards, compared to the old technique of cutting through the palm to reach the tight ligament.

Thousands of patients have found relief from Carpal Tunnel Syndrome via the Brown Procedure and it is now performed worldwide.

Long term recovery

Long-term chronic carpal tunnel syndrome can result in permanent nerve damage. However, most carpal tunnel syndrome sufferers either change their hand use pattern or posture at work or find a soft tissue therapy that allows them to return to full activity without hand pain and sleep disruption. Most people end up prioritizing their activities and give up the least important activities so that they can minimize pain and perform the essential tasks.

Many people change jobs to avoid continued repetitive stress tasks. Some find success by adjusting their repetitive movements, the frequency with which they do the movements, and the amount of time they rest between periods when they perform the movements. The early signs of carpal tunnel syndrome should not be ignored. Early denial of carpal tunnel strain is a sure way to lead to full carpal tunnel syndrome.

Recurrence of carpal tunnel syndrome following treatment is rare. The majority of patients recover completely

See also

• Repetitive strain injury
• mogigraphia

References

• NINDS Carpal Tunnel Syndrome Information Page

External links

• http://www.carpaltunnel.com/

• Carpal Tunnel Syndrome Exercises

• Clinical Study of Soft Tissue Therapy for Treating Carpal Tunnel Syndrome - Dr. Clyde Morgan

Neuromuscular Re-education (NMR) is a highly specialized soft tissue technique that effectively resolves neck, lower back and extremity pain. The foundation upon which NMR is built is the body’s response to inflammation. (http://www.softtissuemonterey.com/neuromuscular.htm) Selective Soft Tissue Therapy

carpal tunnel syndrome treatment with Active Release Techniques

• Conquering Carpal Tunnel Syndrome book review
• Free ergonomics software for RSI prevention and recovery (Windows)
• Software helping to adjust workplace for healthy working and make pauses during work (Windows)
• ICPA Carpal Tunnel Syndrome (Summary of double crush syndrome, with additional references.)
• Alternative Treatment for Carpal Tunnel Syndrome (Case studies relating double crush and carpal tunnel syndrome.)

• Overuse injuries