Carpal tunnel syndrome is a severe, progressive disease that occurs with the compression of the median nerve in the wrist.
Also known as median nerve trapment or median nerve compression, it can occur when a nerve swell, the tendons become inflamed, or something in the carpal tunnel causes swelling.
Symptoms include tingling, burning, or itching, and numbness in hand and finger hands, especially thumb and index finger.
The National Institute of Neurological Disorders and Stroke (NINDS) describes carpal tunnel syndrome (CTS) as “the most serious and generally recognized neuropathy trapment in which the peripheral nerves of the body are squeezed or traumatized.”
In the United States, CTS affects between 3 and 6 percent of adults. It grows normally between the ages of 45 and 64, and the prevalence increases with age. It can appear in a wrist, or both. It’s more popular amongst women than among men.
CTS may have a detrimental effect on a person’s quality of life without medication. The median nerve will eventually get seriously damaged, and there may be permanent numbness in the fingers and permanent weakness in the muscles that the median nerve inerves.
It’s mostly correlated with computer use, but records date back to the 1800s. It had been common to orthopedic surgeons long before computer use was widespread.
Over time, symptoms appear to grow slowly.
Sometimes the first signs occur during the night, or in the morning after waking up. When patients wake up they can feel the need to “shake” their hands out. The pain during the night will wake them up again and again.
These signs arise in the thumb, the two fingers and half of the ring finger next to it. They may extend into the forearm and to the rest of the hand.
Symptoms can continue throughout the day, as the condition progresses. The person may lose grip strength and may find it more difficult to shape a fist or grasp small objects. It may become a challenge to open a bottle of soda, to do buttons or to type in a keyboard.
The muscles at the base of the thumb may wither away if left untreated, and the individual will no longer be able to tell the thumb and finger hot from cold.
Symptoms tend to appear after using the affected hand, or get worse. If the arm or hand has long been in the same place, the feeling of tingling, burning and pain can intensify.
Treatment aims at alleviating symptoms and slowing CTS development by reducing the pressure on the median nerve.
People with mild symptoms can find their condition improves within a few months without treatment , particularly when they are 30 years of age or under, or when CTS occurs during pregnancy.
The following may help reduce discomfort:
- Resting the hand and wrist: The more rest the hand and wrist get, the greater the chance of relieving the symptoms.
- Cold compress: Placing an ice pack on the wrist may help when the problem flares up, but ice should not be applied ice directly onto the skin.
- Controlling the triggers: If CTS stems from repetitive hand movements, the person should take breaks so the hand and wrist have time to rest and recover.
- Occupational therapy: A therapist can teach a person how to repetitive tasks differently.
- Wrist splints: These keep the wrist in the same position and prevent it from bending. They can be worn during sleep, but also during the day if they do not interfere with daily activities. Wrist splints are available over the counter at pharmacies. A doctor or pharmacist can advise about the best one to choose.
Many patients who follow these techniques with mild symptoms will notice an improvement within 4 weeks.
The doctor may recommend injections of corticosteroids to reduce the inflammation. Usually these are applied directly into the carpal tunnel through injection. There are tablets available but typically they are less powerful. The pain may increase at first but it should begin to decrease after 2 days.
If the response is good but symptoms return after a few months, it may be advisable to take another dose. However, it is not advisable to continue the use of corticosteroids, as there may be adverse effects in the long term.
Non-steroidal anti-inflammatory drugs (NSAIDs), such as aspirin or ibuprofen, can help relieve pain at short notice. This can only benefit if the CTS, rather than repeated usage, is due to an underlying inflammatory condition.
Other treatments that may help include exercises and botox injections.
A research published in the journal Clinical Rehabilitation found “solid evidence of the effectiveness of local and oral steroids; moderate evidence that vitamin B6 is ineffective, and splints are effective and minimal or contradictory evidence that NSAIDs, diuretics, yoga, laser, and ultrasound are effective, while exercise therapy and botulinum toxin B injection are ineffective.”
Surgery may be necessary in severe cases where therapies have not been successful and symptoms have continued for at least 6 months.
Carpal tunnel release surgery is an outpatient procedure, also called carpal tunnel decompression. It doesn’t need hospital stay overnight.
Surgery involves cutting the carpal ligament, which is the roof of the carpal tunnel, to reduce pressure on the median nerve.
The Cleveland Clinic reports that CTS surgery has a success rate of more than 90 per cent, and returning to the issue is uncommon.
As with any surgery, complications are always at risk, including infection, post-operative bleeding, nerve injury and scarring.
CTS self-tests involve gently rubbing the wrist to see whether this causes a tingling feeling or numbness in the fingertips.
Another measure is to bend the wrist for a minute, or raise it over the head. If pain, numbness, or tingling occurs, this can mean that CTS is present.
However, these tests are not conclusive.
Typically a primary care physician may diagnose CTS after asking about symptoms, and inspecting the hand and wrist for signs of muscle weakness around the thumb. They’ll also be assessing how well the individual can use the hand and wrist.
A variety of tests can indicate whether a individual will likely have CTS.
Test by Tinel, or sign by Tinel: The doctor taps the median nerve at the wrist gently to see whether the patient experiences numbness or tingling in one or more fingers.
Phalen ‘s wrist-flexion test: The patient presses hand backs against each other to extend the wrist. If tingling or numbness happens within a minute, the median nerve can get affected.
Analysis of nerve conduction: Electrodes are implanted into the hand and wrist. They administer small electrical shocks. The test tests the speed at which the nerves transmit impulses to the muscles.
Electromyography: A fine needle is inserted into the muscle. Electrical activity on a computer will show whether there is any damage to the median nerve, and if so, how significant it is.
Imaging scans: An X-ray will reveal whether a fracture or some other condition, such as rheumatoid arthritis, is present. The median nerve structure can be verified by an ultrasonic scan. Studies also shown that MRI scans are not effective for carpal tunnel syndrome diagnoses.
Here are two exercises that can help to alleviate CTS ‘s discomfort:
- Make a fist, with the handle of the hand facing down. Slide the fingers towards the ceiling until they point straight up. Repeat 5-10 times.
- Make a fist. Open your hand and extend out your fingers, extending them as far as possible. Repeat 5-10 times.
It’s unclear, though, if exercises really have any impact.
The carpal tunnel at the base of the hand, also known as the carpal canal, is a small, rigid passageway between bones and ligaments. The carpal tunnel also contains the median nerve and tendons.
Often the carpal tunnel will widen because the tendons get swollen and inflamed, or some other swelling puts pressure on the median nerve.
The median nerve regulates impulses to the left, the thumb and three other fingers. The median nerve also regulates the muscle that lets the thumb touch the little finger across the palm. It does not control the little finger.
Pressure on this nerve can lead to hand and wrist pain , numbness, and fatigue, and this can cause pain to radiate up the arm and even down to the shoulder.
There are numerous reasons why CTS should develop. However, it is more likely that the person uses extremes of wrist motion regularly, if they are subjected to vibration, and if they use their fingers constantly, for example while typing.
Sometimes, there is no clear cause.
- repetitive maneuvers
- repeated use of vibrating hand tools
- work stress
- pregnancy, for example, because of edema, or fluid retention
- inflammatory, degenerative, and rheumatoid arthritis
- hypothyroidism, or an underactive thyroid
- trauma, such as dislocation or fracture of the wrist
- structural problems in the wrist joint
- lesions in the wrist
- a cyst or tumor in the carpal tunnel
- an overactive pituitary gland
- any kind of swelling or inflammation around the tendons
Research and possible risk factors
Researchers have found that a prior wrist fracture and insulin, metformin, and sulphonylurea use are correlated with increased CTS chances. Smoking, hormone replacement therapy ( HRT), the combination oral contraceptive pill, and oral corticosteroids did not seem to be associated with an increased risk of CTS.
One study indicates that obesity, coupled with a square-shaped shape of the wrist, can increase the risk of developing CTS. The team however concluded that obesity was definitely not the cause, since they continued to have CTS when participants with obesity lost weight.
In addition to work-related causes, inflammatory arthritis is the primary cause for CTS, but hypothyroidism and diabetes also tend to raise the odds of developing it, according to studies reported in the Journal of General Internal Medicine.
The National Institute of Neurological Disorders and Stroke (NINDS) reports that, among people involved in assembly operations, CTS is three times more likely to occur than in data entry workers.
The Canadian Centre for Occupational Health and Safety (CCOHS) list the following occupations as risk factors for CTS:
- farmers, and specifically those milking cows
- workers using air-power hand tools
- assembly-line workers handling objects on the conveyor belt
- check-out cashiers using laser scanners
- factory, farm, or mechanical workers who wear tight gloves
- gardeners weeding by hand
- locksmiths, turning keys
- mechanics, using screwdrivers and pushing down ratchets
- musicians using a bow for a stringed instrument
- office workers using mouse and keyboard
- painters who repeatedly use a spray gun
- poultry or meat processing workers who are deboning and cutting
- stablehands, painters, and carpenters who press tools into the palm
Repetitive movements from activities such as knitting can also increase the risk.
Measures to reduce the risk of developing CTS include:
- not gripping too hard when performing manual tasks
- not overbending the wrist, for example, all the way down or up
- sleeping and working with the wrists straight
- avoiding repeated flexing and extending of the wrists
- maintaining correct posture to prevent putting undue strain on the wrist and hands
- redesigning the workstation to reduce unnatural and awkward wrist positions
- resting and taking frequent breaks when performing routine tasks to protect against the long-term effects
- keeping the hands warm by wearing gloves in a cold environment, as having cold hands can increase the risk of developing CTS
- treating any underlying conditions, for example, establishing good glucose control to help prevent the complications of diabetes
No evidence exists that using a computer raises the risk of CTS, according to the National Library of Medicine, but ergonomic keyboards with an elevated and curved keyboard may minimize tension by helping to hold the hands in a neutral position.
Some people suggest exercises involving hand movement, like yoga, and massages, but research has not established that these are successful.