What is Carpal Tunnel and carpal Tunnal Syndrome (CTS)?
Carpal tunnel syndrome is a common condition which is essentially caused by entrapment of median nerve in the wrist resulting in squeezing or pinching of the median nerve.
carpal tunnel is a narrow passage of ligaments and bones on the palm side of your wrist which houses the median nerve and the tendons that bend the fingers. The median nerve provides feeling to the palm side of the thumb and to index, middle and part of the ring fingers.
When the nerve is squeezed by thickening of irritated tendons, or compressed by other reasons, it results in numbness, weakness, and sometimes pain in the hand and wrist, occasionally extending to forearm and arm.
Who gets carpal tunnel syndrome?
Women are more likely than men to develop carpal tunnel syndrome. This is common in the middle aged and elderly people although, this condition affects people of all ages. It is the most common and widely known form of the entrapment neuropathies.
What are the symptoms of carpal tunnel syndrome?
Symptoms of carpal tunnel syndrome usually start gradually and may include, such as:
- Numbness, tingling, burning and pain primarily in the thumb, index, middle and ring fingers which may also travel to forearm towards shoulders.
- Occasional shock-like sensations that radiate to these fingers.
- Weakness and clumsiness in the hand
The symptoms often first appear in one or both hands during the night, since many people sleep with flexed wrists. Many people try to shake out their hands to get some relief from the symptoms. The numb feeling may become constant over time.
What are the causes of carpal tunnel syndrome?
carpal tunnel syndrome is caused by pressure on the median nerve. It may be caused by aanything that squeezes or irritates or compresses the median nerve in your carpal channel.
CTS does not generally occur due to one reason. It is often the result of a combination of factors that reduce the availability of space for median nerve within the carpal tunnel, rather than a problem with nerve itself.
Pressure on the nerve can happen in several ways, including:
- Swelling of the lining of the flexor tendons
- Joint dislocations
- Fractures
- Arthritis
- Fluid build up during pregnancy or menopause
- Repeated use of vibrating hand tools
- Development of cyst or tumour in the canal
Thyroid conditions and diseases, diabetes and overactive pituitary gland can also be associated with carpal tunnel syndrome.
Often no single cause for this condition can be identified. It may be due to a combination of risk factors which contribute to the development of the condition.
What are the risk factors for carpal tunnel syndrome?
In most of the cases, it is not known what causes the median nerve to get compressed. A number of factors have been associated with carpal tunnel syndrome, although they do not cause CTS directly, but may increase the chances of developing or aggravating median nerve damage. These include:
Family History:
This is likely an important factor and researchers have shown that there is a genetic link to CTS. This means there is increased chance of you developing this condition if other members of your family have it or had in the past.
The exact mechanism through with it gets passed in families have not been understood.
Health Conditions:
Certain health conditions increases your risk for developing CTS.
These include:
- Diabetes
- Arthritis
- Hypothyroidism
- Obesity
- Some drugs used to treat breast cancer such as exemestane
- Cyst, growth or swellings in carpal tunnel
- Nerve inflammation and nerve damaging conditions
- Menopause
- Kidney failure
- Injuries such as sprain fracture or crush injury
Sex:
Women are three times more likely to develop CTS than men. This may be due to carpal tunnel area in women is relatively smaller than in men.
Pregnancy:
carpal tunnel syndrome is common during pregnancy, although the exact cause isn’t known. It generally resolves on its own after pregnancy.
Activities at workplace:
The risk of developing carpal tunnel syndrome is not limited to people in a one particular industry or task, but is particularly common in those industries that involve performing assembly line works such as manufacturing, sewing, finishing, cleaning, meat, poultry, or fish packing or any other form of packing etc.
Certain activities may trigger the development of carpal tunnel syndrome. These activities mainly tend to involve strenuous grip, repetitive wrist bending and exposure to vibration.
Examples are:
- Playing musical instruments
- Assembly packing
- Work involving manual labour
- Work with vibrating tools such as chainsaws
How is carpal tunnel syndrome diagnosed?
There are several ways to diagnose carpal tunnel syndrome, including physical examination and testing.
Your doctor will ask a number of questions and conduct one or more of the following tests to confirm whether you have carpal tunnel syndrome:
History of symptoms:
Your doctor will review the pattern and severity of symptoms.
Physical Examination:
Your doctor will conduct a physical examination. He or she will test the feeling in your fingers and the strength of the muscles in your hand. During this, your doctor will:
- Tap over the median nerve on the palm side of your wrist to see if it causes any numbness or tingling in your fingers (Tinel’s test)
- Ask you to bend your palm towards your forearm up for a minute (Phalens’s test)
- Test sensitivity in fingertips
- Check for weakness in the muscles around the base of your thumb
- Look for atrophy in the muscles around the base of your thumb
The wrist is examined for tenderness, swelling, warmth, and discoloration. These tests can help to confirm carpal tunnel syndrome, though they aren’t fully reliable so you may also have one of the tests described below.
Tests:
Sometimes, the condition is mistaken for something else. Further testing may be required in these cases if your doctor is uncertain and wants to rule out other conditions that have similar symptoms.
Blood test:
A blood test can be used if the doctor suspects an underlying condition relating to CTS, such as diabetes, rheumatoid arthritis and underactive thyroid gland.
Electrophysiological tests:
These tests will help your doctor to determine whether there is pressure on the median nerve, if any, and its severity and how well your median nerve is working.
These tests can also reveal any other nerve conditions you may have such as neuropathy or other site of compression on the nerves.
Electrophysiological test may include:
Nerve conduction studies:
A nerve conduction study is a test that measures how fast the signals are transmitted through your nerves. These tests measure the signals travelling in the nerves of your hand and arm and can detect when a nerve is not conducting its signal effectively.
There are ways to perform nerve conduction studies through which your doctor determine how acute your problem is and accordingly can help plan the treatment.
Nerve conduction studies are usually performed in hospitals and take about 10 minutes. They’re generally not very painful, but may be uncomfortable.
Electromyogram (EMG):
An EMG measures the electrical activity in muscles. EMG provides important information to your doctor about whether you have any nerve or muscle damage.
Ultrasound:
An ultrasound uses high frequency sound waves to create pictures of bones and tissues. Your doctor may advice for an ultrasound of your wrist to evaluate median nerve for signs of compression. Ultrasound imaging can show abnormal size of the median nerve.
X- rays:
X-rays generate images of dense structures, such as your bones. If you have problem in wrist motion or have wrist pain, your doctor may ask for x-rays to rule out other causes for the symptoms you might be experiencing, such as arthritis, ligament injury, or a fracture as these diseases may show similar signs and symptoms.
Magnetic resonance imaging (MRI) scans:
Magnetic resonance imaging (MRI) is generally used to study the anatomy of the wrist but it has not been particularly useful in diagnosing carpal tunnel syndrome.
An MRI can also help your doctor determine if there are problems with the nerve itself—such as due to scarring from an injury or tumour. In fact, MRI is most commonly used in detecting tumours or bone cancers or bone cysts and therefore your doctor may want to order this test to rule out these conditions.
How can carpal tunnel syndrome be prevented?
There are no proven ways to prevent carpal tunnel syndrome (CTS), but you can minimize the stress on your hand by following certain methods, which in return will help in decreasing the likelihood of getting CTS. These are listed here:
- Reduce your force and relax your grip
- Take frequent breaks from your tasks
- Avoid bending your wrist all the way up or down
- Maintain your posture
- Change your computer mouse if its giving stress on your wrist
- Keep your hands warm if you work in cold environment. Wearing fingerless gloves can help keep hands warm and flexible
What are the treatment options for carpal tunnel syndrome?
Treatment of carpal tunnel syndrome depends on the severity of the nerve damage and your preferences. Since it’s a progressive condition, it gets worsen with time without any form of treatment.
It is advised to start treatment as early as possible to slow down or stop the disease progression. Underlying causes such as diabetes and arthritis should be treated first.
Treatment options can be divided in non-surgical and surgical category.
Non-surgical treatments:
Splinting:
Initial treatment is usually a splint worn at night.
Avoiding daytime activities that may provoke symptoms
Avoid any such activity that may likely cause or worsen the symptoms.
Over- the counter drugs:
In special circumstances, drugs can ease the pain and swelling associated with carpal tunnel syndrome. Non-steroidal anti-inflammatory drugs, such as aspirin, ibuprofen, and other non prescription pain relievers, may provide some short-term relief from discomfort but haven’t been shown to treat CTS itself.
Prescription medicines:
Corticosteroid, or cortisone, is a powerful anti-inflammatory agent that can be injected into the carpal tunnel. Although these injections generally help relieve from painful symptoms and calm down a flare up, but their effectiveness is sometimes only temporary and the pain may appear again soon.
Alternative therapies:
Yoga has been shown to reduce pain and improve grip strength among those with CTS. Some people report relief using acupuncture and chiropractic care but the effectiveness of these therapies remains unproved.
Surgery for carpal tunnel syndrome
Surgery may be appropriate if your symptoms are worse and not responding to other treatments. Generally, surgery involves severing a ligament around the wrist to reduce pressure on your median nerve that might be causing the CTS pain.
Surgery is usually done under local or regional anaesthesia (involving some sedation) and does not require an overnight hospital stay. Many people require surgery on both hands. While all carpal tunnel surgery types involve cutting at least a portion of the ligament to relieve the pressure on the nerve, there are two different methods that are generally used by surgeons to do this.
Open carpal tunnel release:
Your surgeon makes an incision up to 2 inches in the palm of your hand over the carpal tunnel and cuts through the ligament to free the nerve. This process is generally performed under local anaesthesia on an outpatient basis.
Endoscopic carpal tunnel release:
Your surgeon uses a telescope-like device with a tiny camera attached to it (endoscope) to see inside your carpal tunnel.
Your surgeon cuts the ligament through a few (such as one or two) small incisions in your hand or wrist. Endoscopic surgery may result in less pain than does an open surgery in the first few days or weeks after surgery.
