Carpal tunnel syndrome
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Carpal tunnel syndrome is a disorder 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 most famous of a class of disorders called repetitive strain injuries.
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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. As well as 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, or by direct pressure from part of a broken or dislocated bone.
Incidence
The syndrome is much more common in women than it is in men.
Symptoms
The first symptoms usually appear at night. 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.
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.
There are a number of causes of carpal tunnel syndrome. They can be either traumatic, or non-traumatic. Trauma-based causes:
- 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 CTS is the biggest single contributoring factor to lost time at work. This type of CTS results in billions of dollars of workers compensation claims every year.
- Fractures of one of the arm bones, particularly a Colles' fracture.
- Dislocation of one of the carpal bones of the wrist.
- 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.
- Idiopathic causes, which no-one can explain, can also cause this disease.
Common activities that have been identified as contributing to repetitive stress induced CTS include:
- Computer Keyboarding or typing
- Playing a musical instrument
- Driving a vehicle, motorcycle or flying a plane
- Any activity where hand use is vigorous and routine could contribute.
- An exhaustive list can be found in the external links below
Often people suffering from CTS 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
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.
Phalen's maneuver is another test for carpal tunnel syndrome. The patient is asked to keep their wrist at the extremity of flexion for 30 seconds. The aim is to compress the carpal tunnel and thus elicit the characteristic symptoms of the carpal tunnel syndrome. If the patient experiences a burning, tingling or numb sensation over the thumb, index, middle and ring fingers, then the test is positive. Phalen's maneuver is more sensitive than Tinel's sign.
Treatment
In general, if a specific action or movement (such as typing on a keyboard, or gripping a hammer) is causing pain, then simply avoiding this action may be enough to alleviate symptoms. Unfortunately, this doesn't always work and a person's job may preclude simply stopping.
Carpal tunnel syndrome is treated by immobilizing the wrist in a splint to minimize or prevent pressure on the nerves (the use of splints for anything other than a short time is considered by many to be non productive). Muscle attrophy is a common result of wearing hand and wrist braces or splints.
Patients suffering from CTS are sometimes given anti-inflammatory drugs or injections of cortisone in the wrist to reduce the swelling. This offers relief for a few months while the CTS sufferer evaluates other options. Steroid injections are not a long-term answer for Carpal Tunnel Syndrome.
Carpal tunnel syndrome can also be treated non-surgically through the use of Active Release Techniques also known as Soft Tissue Therapy (http://en.wikipedia.org/wiki/Soft_tissue_therapy). The purpose of Active Release Techniques is to reduce the scar tissue adhesions, increase muscle elasticity, and increase strength. Also, new breakthroughs in Soft Tissue Therapy have been developed in recent years by physicians to reduce compression of the median nerve in the carpal tunnel allowing sufferers to gain control over their symptoms and avoid surgery. Physicians and medical insurance providers recommend exhausting all conservative treatment options before resorting to surgery.
There is also a surgical procedure in which doctors can open the wrist and cut the ligament (the flexor retinaculum) at the bottom of the wrist to relieve the pressure. However, surgery should be considered as a last resort and only after all conservative treatments have been exhasuted. The surgery itself is brief, and only a local anaesthetic is needed. The carpal ligament is severed, relieving pressure on the median nerve. The incision is then sutured and the ligament left to scar back together on its own, with the hope that there will be more space left after recovery. Full recovery is only achieved in less than 60% of recipients. Downtime and rehabilitation can take up to three months. Also, since CTS is a syndrome, not a disease, if repetitive stress activities are continued, then surgery will likely have to be repeated within a year or two. Like many surgical procedures, Carpal Ligament Release Surgery can also be done endoscopically, but due to the proximity to the medium nerve the risk of damaging the median nerve in this tight space is increased in this procedure, a skilled surgeon is essential for this type of surgery.
Long Term Recovery
Long-term chronic Carpal Tunnel Syndrome can result in permanent nerve damage. However, most CTS 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. Less than 1% experience long-term nerve damage. 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 on Carpal Tunnel Syndrome.
See also
References
- NINDS Carpal Tunnel Syndrome Information Page (http://www.ninds.nih.gov/health_and_medical/disorders/carpal_doc.htm)
External links
- Carpal Tunnel Syndrome is the leading cause of loss time at work in most industrialized countries (http://www.mycarpaltunnel.com/losing-earnings-carpal-tunnel-syndrome.shtml)
- Breakthrough Soft Tissue Therapy Developed by a Physician Specifically for CTS (http://www.mycarpaltunnel.com/how-carpal-solution-works.shtml)
- Carpal Tunnel Syndrome treatment (http://www.chirotx.com/active_release_technique_carpal_tunnel_novato.htm) treatment with Active Release Techniques
- Conquering Carpal Tunnel Syndrome (http://www.chirotx.com/books/reviews/conquering_carpal_tunnel_syndrome/index.htm) book review
- Hand Activities identified as contributing to repetitive stress induced carpal tunnel syndrome (http://www.mycarpaltunnel.com/faq-carpal-tunnel-syndrome/what-causes-carpal-tunnel-syndrome.shtml)