What is carpal tunnel syndrome?
Carpal tunnel syndrome (CTS) is a common condition that affects the hand, wrist, and occasionally the entire upper extremity. The tunnel itself is a narrow canal at the base of the palm that is defined by the bones of the wrist and the overlying transverse carpal ligament. The nine flexor tendons to the fingers and thumb, and the median nerve pass through the tunnel. The median nerve provides sensation to the thumb, index, and long fingers, and to part of the ring finger. It also provides strength to the muscles at the base of the thumb. CTS is a constellation of symptoms resulting from compression or adherence of the median nerve at the base of the palm.
What are the symptoms of carpal tunnel syndrome?
Characteristic early symptoms include numbness at night, tingling, or pain in the fingers (especially the thumb, index, and long fingers). The patient will often awaken with these symptoms and attempt to shake the hand or hold it in a dependent position to relieve symptoms. As the problem worsens, the symptoms become more prominent during the daytime, especially while driving, brushing hair and holding the phone or a book. The patient also may begin to experience weakness and may occasionally drop objects, often without realizing they are losing their grip until it is too late.
What causes carpal tunnel syndrome?
CTS is a disorder that can potentially affect many patients because of the demands placed on the hands through life. The causes of CTS are varied and may include the following:
- Inflammation and swelling around the tendons
- Fluid retention (e.g., during pregnancy)
- Wrist fracture and dislocation
- Degenerative and rheumatoid arthritis
- Aberrant anatomy
Occupational factors that seem to contribute to the onset of CTS include repetitive finger use associated with high force, long duration, and extremes of wrist motion and vibration. Computer keyboard use is a factor; however, it is not solely responsible for the onset of CTS.
If you develop the symptoms of carpal tunnel syndrome, splint your wrist in a straight position and see your doctor. Significant delay can allow the condition to become so severe that treatment may not be effective.
How is carpal tunnel syndrome diagnosed?
Some of the methods used to diagnose CTS include:
- Tinel's sign — The physician taps over the median nerve at the wrist to produce a tingling sensation in the involved digits.
- Wrist flexion test (or Phalen test) — The patient rests his or her elbows on a table and allows the wrist to fall forward freely. Individuals with CTS experience numbness and tingling in the fingers supplied by the median nerve within sixty seconds.
- X-rays — These help rule out other conditions such as arthritis.
- Electrical studies (EMG) — These studies are used to quantify median nerve conduction and severity of CTS.
How can carpal tunnel syndrome be prevented?
Because there are many causes of CTS, it is very difficult to prevent the development of this syndrome. Ergonomic modifications at work can help minimize some of the occupational factors that seem to contribute to CTS. The workstation should be physically accommodating and comfortable, with proper lighting, seating and hand/wrist placement. The following is a list of preventive measures:
- Sleep with your wrists straight.
- Keep your wrists straight when using tools.
- Avoid flexing and extending your wrists repeatedly.
- Minimize repetitive, strong grasping with the wrist in a flexed position.
- Take frequent rest breaks.
- Perform conditioning and stretching exercises.
How is carpal tunnel syndrome treated?
Treatment begins with job and activity modifications as outlined above. Night wrist splints can help prevent wrist hyperflexion, which naturally occurs during sleep. That treatment may rest the nerve and lessen night awakenings, as well as improve daytime symptoms. Sometimes, anti-inflammatory medications either taken orally or injected into the carpal tunnel can help diminish swelling around the median nerve and lessen symptoms. Generally, cortisone injections provide only temporary relief.
Surgery is recommended when CTS does not respond to these conservative measures or has already become severe, as judged by physical examination and EMG tests. The goal of surgery is to decrease pressure on the nerve by enlarging the carpal canal. This is accomplished by dividing the ligament that covers the carpal tunnel at the base of the palm—the transverse carpal ligament—through an incision approximately one inch in length.
Surgery for CTS is an outpatient procedure that is usually performed under local anesthesia. Brief surgical discomfort lasts 24 to 72 hours; however, patients often experience complete resolution of their nighttime symptoms even the night after surgery. Sutures are removed 10 to 14 days after surgery, and hand and wrist use for everyday activities is gradually restored using progressive exercise.
Heavier activities with the affected hand are restricted for four to six weeks. Recovery times vary depending on the patient's age, general health, severity of CTS, and the length of time the symptoms have been present. Strength and sensation continue to improve over the ensuing year.
Although the great majority of patients who undergo carpal tunnel release experience virtually complete relief of all symptoms, some individuals with severe CTS may be left with some residual numbness. Recurrences can occur, but they are highly unusual.
Myths and truths about carpal tunnel syndrome
Myth — Most pain in the hand is caused by carpal tunnel syndrome.
Truth — While carpal tunnel syndrome is common, it does cause a characteristic set of symptoms which differentiates it from the many other causes of hand pain
There are other conditions that are similar to, or associated with, CTS. One of these is de Quervain’s disease, an inflammation affecting the base of the thumb. Another inflammatory disorder is trigger finger, which occurs around the flexor tendons, generally in the palm where the first pulley exists. An inflamed tendon becomes thick and rough and is unable to move back and forth beneath the pulley.
Myth — Carpal tunnel syndrome is a condition of the 90's.
Truth — It was first described in the mid 1800's. The first surgery for release of the carpal tunnel was done in the 1930's. It is a condition that has been well recognized by orthopaedic surgeons for over 40 years.
Myth — CTS occurs only in office workers or factor assembly line workers.
Truth — Many patients with carpal tunnel syndrome have never done office work or worked on an assembly line.
Anyone can get carpal tunnel syndrome but it is unusual before age 20 and the incidence increases with age. Women have a slightly higher incidence. It affects people who use their wrists and hands repeatedly at work and at play.
Myth — It takes a long time to recover from surgery to treat carpal tunnel syndrome.
Truth — The bandage can be removed in two days and the incisions covered with bandages. The hand can then be used for light activities. Making a fist is encouraged. By two weeks when the sutures are removed there is usually full motion of the fingers and relief of the symptoms. Some surgeons prefer to splint the wrist for two weeks or so after surgery. You are usually back to most activities by 6 weeks. Return to work depends on many factors such as type of work and how much control you have over your work.
Myth — Surgery usually doesn't work.
Truth — Surgery has a high success rate, over 90 percent.
The tingling and waking up at night is usually relieved fairly quickly, as is any pain that is coming from the CTS. The numbness may take longer to be relieved, even up to three months. Surgery won't help if CTS is the wrong diagnosis. When the CTS has become severe relief may not be complete. There may be some pain in the palm around the incisions which can last up to a few months. Other residual pain may not be related to the carpal tunnel syndrome. Patients who complain that their symptoms are unchanged after surgery either had severe CTS; had a nerve that was not completely released during surgery; or did not really have CTS. Only a small percentage of patients do not gain complete relief from symptoms.
Myth — CTS frequently comes back after surgery.
Truth — Recurrences are unusual.
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 1/14/2010…#4005
This information is provided by Cleveland Clinic and is not intended to replace
the medical advice of your doctor or health care provider.
Please consult your health care provider for advice about a specific medical condition.