What is carpal tunnel syndrome?
Carpal tunnel syndrome is a common condition that causes pain, numbness, tingling and weakness in the hand and wrist. It occurs when there is increased pressure within the wrist on a nerve called the median nerve. This nerve provides sensation to the thumb, index, and middle fingers, and to half of the ring finger. The small finger (the “pinky”) is typically not affected. The median nerve also provides strength to some of the muscles at the base of the thumb and index finger.
What is the carpal tunnel?
The carpal tunnel is a narrow canal or channel in the wrist. The bottom and sides of the tunnel are formed by a semi-circle of bones called carpal bones. A strong tissue, called a ligament, forms the top of the tunnel. The median nerve and tendons pass through this narrow space. The tendons are rope-like structures that connect muscles in the forearm to bones in the hand. Tendons allow the fingers and thumb to bend and straighten. Conditions that further narrow the carpal tunnel or cause the tendons that pass through this tunnel to swell cause carpal tunnel syndrome by compressing the median nerve.
Who is at risk for carpal tunnel syndrome?
People at risk are those with jobs or activities that involve repetitive finger use, especially those associated with high force, long-term use, extreme wrist motions and vibration. However, many factors may contribute to the development of carpal tunnel syndrome. They include:
What are myths about carpal tunnel syndrome?
- Myth: Most hand pain is caused by carpal tunnel syndrome.
- Truth__: It’s true that carpal tunnel syndrome is a common condition. However, it does have a set of symptoms that are different from many other sources of hand pain. Even so, there are several other hand pain conditions similar to, or associated with, carpal tunnel syndrome. One of these is de Quervain’s tendinosis. This is an inflammation (swelling) that affects the wrist and the base of the thumb. Another inflammatory disorder is called trigger finger. Trigger finger causes soreness at the base of the finger or thumb. It also causes pain, locking (or catching) and stiffness when bending the fingers and thumb.
- Myth: Carpal tunnel syndrome is a condition of the 1990s.
- Truth__: It was first described in the mid-1800s. The first surgery for release of the carpal tunnel was done in the 1930s. It is a condition that has been well recognized by orthopaedic surgeons for over 40 years.
- Myth: Carpal tunnel syndrome 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. The chance of getting carpal tunnel syndrome increases with age. Women have a slightly higher chance of getting carpal tunnel syndrome. 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 that covers the stitches after surgery can be removed in a few days. The hand can then be used for light activities. Making a fist is encouraged. Full range of finger motion and early symptom relief is usually seen within two weeks after stitches have been removed. You can usually return to most activities by six weeks. Your return to work depends on factors such as type of work, how much control you have over your work and workplace equipment.
- Myth: Surgery usually doesn’t work.
- Truth__: Surgery has a high success rate, over 90 percent. The tingling sensation and waking up at night is usually relieved fairly quickly, as is any pain that is coming from the carpal tunnel. Numbness may take longer to be relieved, even up to three months. Surgery won’t help if carpal tunnel syndrome is the wrong diagnosis. When the carpal tunnel syndrome has become severe, relief may not be complete. There may be some pain in the palm around the incisions that can last up to a few months. Other after-surgery pain may not be related to carpal tunnel syndrome. Patients who complain of pain or whose symptoms remain unchanged after surgery either had severe carpal tunnel syndrome; had a nerve that was not completely released during surgery; or did not really have carpal tunnel syndrome. Only a small percentage of patients do not gain substantial relief from symptoms.
- Myth: Carpal tunnel syndrome frequently comes back after surgery.
- Truth__: It is unusual for carpal tunnel to come back after surgery.
What are the symptoms of carpal tunnel syndrome?
Symptoms usually begin slowly and can occur at any time. Early symptoms include:
- Numbness at night
- Tingling and/or pain in the fingers (especially the thumb, index and middle fingers)
In fact, because some people sleep with their wrists curled, nighttime symptoms are common and can awake people from sleep. These nighttime symptoms are often the first reported symptoms. Shaking the hands helps relieve symptoms in the early stage of the condition.
Common daytime symptoms can include:
- Tingling in the fingers
- Decreased feeling in the fingertips
- Difficulty using the hand for small tasks, like:
- Handling small objects
- Grasping a steering wheel to drive
- Holding a book to read
- Using a computer keyboard
As carpal tunnel syndrome worsens, symptoms become more constant. These symptoms can include:
- Weakness in the hand
- Inability to perform tasks that require delicate motions (such as buttoning a shirt)
- Dropping objects
In the most severe condition, the muscles at the base of the thumb visibly shrink in size (atrophy).
As carpal tunnel syndrome worsens, symptoms become more constant. Weakness in the hand, inability to perform tasks that require delicate motions (such as buttoning a shirt), and dropping objects begin to occur. In the most severe condition, the muscles at the base of the thumb visibly shrink in size.
How is carpal tunnel syndrome diagnosed?
First, your doctor will discuss your symptoms and medical history and examine you. Next, tests are performed, which may include:
- Tinel’s sign. In this test, the physician taps over the median nerve at the wrist to see if it produces a tingling sensation in the fingers.
- Wrist flexion test (or Phalen test). In this test, the patient rests his or her elbows on a table and allows the wrist to fall forward freely. Individuals with carpal tunnel syndrome will experience numbness and tingling in the fingers within 60 seconds. The more quickly symptoms appear, the more severe the carpal tunnel syndrome.
- X-rays. X-rays of the wrist may be ordered if there is limited wrist motion, or evidence of arthritis or trauma.
- Electromyography (EMG) and nerve conduction studies. These studies determine how well the median nerve itself is working and how well it controls muscle movement.
How is carpal tunnel syndrome treated?
Non-surgical treatments are usually tried first. Treatment begins with wearing a wrist splint at night and taking nonsteroidal anti-inflammatory drugs, such as ibuprofen, to relieve pain. Cortisone injections can also be given though they provide only temporary relief of symptoms, but may provide evidence of confirmation of the diagnosis.
Changes can also be made to the work station. Examples include raising or lowering the chair or the computer keyboard to bring the patient into proper alignment. Changes can be tried in the hand/wrist positions used in jobs and other activities, along with activity modification. Hand therapists can provide instruction in splinting, exercise and heat treatment, as well as ergonomic work modification.
Surgery is recommended when carpal tunnel syndrome does not respond to non-surgical treatments or has already become severe.
The goal of surgery is to increase the size of the tunnel in order to decrease pressure on the nerves and tendons that pass through the tunnel. This is done by cutting (releasing) the ligament that covers the carpal tunnel at the base of the palm. This ligament is called the transverse carpal ligament.
- Surgery for carpal tunnel syndrome is an outpatient procedure that is usually performed under local anesthesia (you will be awake) but sedation can be added for comfort.
- After surgery, brief discomfort lasts 24 to 72 hours. Patients often experience complete nighttime symptom relief even the night after surgery.
- Stiches are removed 10 to 14 days after surgery. Hand and wrist use for everyday activities are gradually restored using a specific exercise program.
- 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 carpal tunnel syndrome, and the length of time symptoms have been present. Strength and sensation continue to improve over the following year.
- Many patients who undergo carpal tunnel release surgery achieve nearly complete relief of all symptoms. Recovery in some individuals with severe carpal tunnel syndrome may be slow and may not be complete.
- Carpal tunnel syndrome can reoccur, but this is not common.
How can carpal tunnel syndrome be prevented?
Because of its many causes, carpal tunnel syndrome is difficult to prevent. Workstation changes, such as proper lighting and seating and hand/wrist placement, can help decrease some factors that can lead to carpal tunnel syndrome. Other preventive methods include:
- Sleep with your wrists held straight.
- Keep your wrists straight when using tools.
- Avoid flexing (curling) and extending your wrists repeatedly.
- Decrease repetitive/strong grasping with the wrist in a flexed position.
- Take frequent rest breaks from repetitive activities.
- Perform conditioning and stretching exercises before and after activities.
- Monitor and properly treat medical conditions linked to carpal tunnel syndrome.
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