What is Carpal Tunnel Syndrome?
Carpal tunnel syndrome, or CTS, happens when the median nerve, which passes through the “carpal tunnel” in your wrist, gets squashed. This is usually due to heightened pressure within this tunnel. The first signs of CTS are typically pain, a tingling sensation, or numbness that affects the thumb, index, and middle fingers, and half of the ring finger. People with CTS also feel pain in their wrist, sometimes radiating to their whole hand, or even up their forearm, but it usually does not reach the neck. As it progresses, CTS can lead to hand weakness, clumsiness, problems with delicate movements, and a gradual wasting away of the thumb muscles.
These symptoms are usually worse during the night or when the person is lying down, and seem to get better during the day. However, over time, they can also occur during the day, especially when doing the same actions repeatedly, like drawing, typing, or playing video games. In severe cases of CTS, these symptoms can become continuous.
Jobs that require a lot of computer use or doing the same movements over and over, and using vibrating tools, can heighten the chances of someone getting CTS, as can being overweight, genetics, diabetes, rheumatoid arthritis, hypothyroidism, and pregnancy.
The exact treatment for CTS hinges on how severe it is. For most people, the first step is to try less invasive methods. Those with intense symptoms or whose condition doesn’t improve with regular treatments may need to think about surgery.
What Causes Carpal Tunnel Syndrome?
The carpal tunnel is a small pathway in your wrist, formed by a ligament on top and wrist bones underneath. This tunnel hosts 9 tendons, which help bend your fingers, and the median nerve, which runs through it. Carpal tunnel syndrome (CTS) can happen due to injuries, high pressure, or problems in blood supply to the median nerve.
The pressure inside your carpal tunnel is usually between 2 to 10 mmHg. However, certain hand positions, such as bending or straightening the wrist, can increase the pressure up to 10 times. When the nerve in the carpal tunnel is constantly squished, it can start to lose its outer covering at the compression point. A type of swelling, known as endoneurial edema, can occur if blood flow to a tiny blood vessel system is interrupted.
While we don’t fully understand why the pressure in the carpal tunnel increases, having certain conditions can increase your risk of getting CTS. Your chances of getting CTS increase if the shape of your carpal tunnel changes, your body’s water balance is off, or there are direct nerve damaging factors.
Here are some possible risk factors for CTS:
* Carpal bones out of place
* Fractured or improperly healed wrist bone at the edge of your hand
* Wrist joint diseases, including those that cause swelling due to inflammation or infections
* Overgrowth of body tissues, known as acromegaly
* Cysts or tumors in the tunnel
* Pregnancy
* Menopause
* Obesity
* Kidney failure
* Low thyroid hormone levels
* Using birth control pills
* Congestive heart failure
* Diabetes
* Alcohol addiction
* Lack or overdose of vitamins
* Exposure to harmful substances
One way to determine the risk of CTS is the square wrist test, where the thickness of your wrist is compared to its width. If this ratio is more than 0.7, it could mean a higher risk of developing CTS.
Risk Factors and Frequency for Carpal Tunnel Syndrome
CTS, or Carpal Tunnel Syndrome, affects about 1% to 5% of people in general. Women are three times more likely to have it than men. If a person is obese, their chance of getting CTS doubles. It’s a rare condition in children, and usually shows up in adults aged 40 to 60.
- CTS affects 1% – 5% of the general population.
- Women are three times more likely to have it than men.
- Obesity doubles the risk of developing CTS.
- CTS is rare in children, but usually occurs in adults aged 40 to 60.
Signs and Symptoms of Carpal Tunnel Syndrome
Carpal tunnel syndrome (CTS) often causes numbness, tingling, and pain in the thumb, second, third, and radial parts of the fourth finger which can worsen at night. The discomfort may only be in the wrist, or it can involve the entire hand, travel up the forearm, or even reach up beyond the elbow to the shoulder.
At first, the symptoms come and go, usually appearing during activities like driving, reading, or painting. Nighttime symptoms, especially if shaking the hand or wrist relieves them, usually indicate CTS. If the condition progresses, the patient may experience constant loss of sensation, muscle weakness, clumsiness and difficulty in opening doors or buttoning clothes. Although it’s possible to have CTS in both hands, it usually starts in the dominant hand. If the numbness extends to the fifth digit, thenar eminence, back of the hand or neck, then the issue might not be CTS.
During a physical exam, the doctor may find loss of sensation or weakness in the area supplied by the median nerve. The palm of the hand usually doesn’t experience sensory loss, as the nerve supplying it doesn’t pass through the carpal tunnel. Other potential signs include weakened thumb movement and muscle wasting at the base of the thumb.
Several tests can help recreate the symptoms of CTS but they vary in their accuracy. It is important to also consider the patient’s medical history.
- The carpal compression test, the most reliable test, involves applying pressure over the carpal tunnel for 30 seconds. If tingling or pain occur within the area supplied by the median nerve, the test is positive. It has a sensitivity of 64% and a specificity of 83%.
- The Phalen test, or reverse prayer, involves the patient holding their wrists together in full flexion for 1 minute. A positive test results in pain and tingling in the fingers supplied by the median nerve. It has a sensitivity of 68% and a specificity of 73%.
- In the Tinel test, the health professional taps over the carpal tunnel to provoke a response from the median nerve. If symptoms occur, the test is positive. This test has a sensitivity of 50% and a specificity of 77%.
Testing for Carpal Tunnel Syndrome
For mild Carpal Tunnel Syndrome (CTS), usually, no extra diagnostic tests are needed except for pregnant people, and in certain situations like persistent numbness, weakness in hand, sleep-disturbing pain, or any trouble in hand functioning. In these cases, electrodiagnostic tests including nerve conduction studies are useful. To assist with surgery decisions and rule out other conditions, an Electromyography (EMG) can be performed. This can also reveal nerve integrity even when no sensory or motor signals are detected.
When specific signs and symptoms tie up with abnormalities found in electrodiagnostic tests, it’s considered the best way to diagnose CTS. These tests can also tell us about the severity of nerve damage and predict its outcome, as symptoms might not always tell the exact level of median nerve damage. Generally, CTS is divided into three levels of severity – mild, moderate, and severe. Mild cases only show sensory abnormalities, while moderate ones show both sensory and motor abnormalities in electrophysiologic tests.
Imaging tests are only needed if a structural abnormality is suspected, such as tumors or ganglion cysts. For these cases, the preferred imaging methods are ultrasound or magnetic resonance imaging.
Treatment Options for Carpal Tunnel Syndrome
If you’ve got mild Carpal Tunnel Syndrome (CTS), the first step usually includes conservative treatments like wearing a wrist splint at night or getting glucocorticoid injections. The wrist splint, which is often the preferred approach, helps maintain a neutral wrist position while you sleep. It’s usually a good idea to check in with your doctor after 1 or 2 months to see how well this treatment is working. If your symptoms are getting better, you can continue with the splint. But, if there’s no improvement, it might be worth considering combining the splint with other treatments.
Glucocorticoid injections can provide quicker relief than splints, but in the long run, both treatments have similar success rates. These injections are a viable alternative to wrist splints, especially if you want faster relief of symptoms. The usual practice is to inject a mix of methylprednisolone and 1% lidocaine into the carpal tunnel, sometimes using ultrasound for guidance. While the relief from injections usually lasts about 3 months, doctors generally recommend limiting these injections to once every 6 months for each wrist. If you do not respond well to 1 or 2 injections, you might need to consider surgery. Keep in mind, though, that these injections have potential side effects like worsening nerve compression, injure nerves or risk tendon rupture.
If conservative treatments still don’t work, you may need to try a combination of a splint and an injection. If you’d rather avoid injections, taking oral prednisone for a short period (about 10 to 14 days) might help. However, it’s not recommended to use oral glucocorticoids for extended periods due to potential side effects.
Another option is to get help from a specialized hand therapist. They can teach you techniques such as bone mobilization, nerve and tendon-gliding exercises, and ultrasound therapy. However, take note that oral agents have not proven more effective than placebos in treating CTS. Drugs like nonsteroidal anti-inflammatory medications and diuretics are usually ineffective.
Lastly, for people with severe CTS or those who do not respond to other treatments, surgery may be required. You would need to undergo electrophysiological testing before carpal tunnel release surgery. This is a minimally invasive procedure to relieve pressure on the median nerve where a small cut is made in the transverse carpal ligament. Patients usually go home the same day without needing to stay overnight in the hospital. Remember, while surgery has better long-term outcomes compared to conservative therapy, it’s worth noting that the success rates decrease slightly after a 5-year mark, with rates falling to around 60%.
What else can Carpal Tunnel Syndrome be?
If a person is suspected of having Carpal Tunnel Syndrome (CTS), it’s important to realize that the symptoms could also be due to other medical conditions affecting the muscles and nerves. When a doctor is examining a patient who might have CTS, they should also consider the following potential diagnoses:
- Brachial plexopathy (nerve injury in the shoulder)
- Cervical myofascial pain (neck and shoulder pain)
- Cervical spondylosis (wear and tear in the neck)
- Compartment syndrome (pressure buildup in muscles)
- Ischemic stroke (blockage of blood flow in the brain)
- Mononeuritis multiplex (damage to multiple nerves)
- Multiple sclerosis (disease affecting the central nervous system)
- Median neuropathy in the forearm (nerve damage in the arm)
- Motor neuron disease (muscle disease)
- Diabetic neuropathy (nerve damage due to diabetes)
- Cervical radiculopathy (pinched nerve in the neck)
- Overuse injury (injury from repeated actions)
- Traumatic brachial plexopathy (nerve damage due to shoulder injury)
- Radiation-induced brachial plexopathy (nerve damage from radiation therapy)
- Neuropathies (general term for nerve disease or damage)
- Tendonitis (inflamed tendon)
- Tenosynovitis (inflammation of the sheath around a tendon)
- Thoracic outlet syndrome (nerves compressed in neck and shoulder)
These disorders can resemble CTS, so the physician must conduct the appropriate tests to reach an accurate diagnosis.
What to expect with Carpal Tunnel Syndrome
Carpal Tunnel Syndrome (CTS) often gets worse over time and can cause permanent harm to the median nerve. Even after surgery, some people may see the symptoms come back, with up to one-third of patients experiencing this within five years. Fortunately, between 70% to 90% of mild-to-moderate cases of CTS improve with non-surgical treatment strategies.
However, it’s not unusual for the condition to worsen to the point where surgery becomes necessary. Those who develop CTS due to diabetes or a wrist injury tend to have less positive outcomes than people without any clear underlying cause. Also, patients with normal test results for nerve function tend not to do as well after surgery and face more complications than those with test results showing abnormalities.
In fact, if nerve damage is detected during these tests, it often suggests a less favorable outcome.
Possible Complications When Diagnosed with Carpal Tunnel Syndrome
Carpal Tunnel Syndrome (CTS) can lead to various problems, either due to the condition itself or from the treatment methods used. The disease can cause irreversible damage to the median nerve in your wrist, potentially resulting in lasting disability. You could also experience muscle weakness and wasting away of the muscle at the base of your thumb. This could affect your ability to use your hand effectively. The condition may also cause chronic, long-term pain in your wrist and hand, and in serious cases, it can even lead to the development of a complex pain disorder in the affected region.
Surgery to treat CTS can also lead to several complications. The most common is the development of a neuroma, a type of nerve damage, in the branch of the median nerve in the palm of your hand. People who have had this surgery may also experience:
- Raised, oversized scars
- Stiff joints
- Dysesthesias, a type of abnormal sensation
- Continuing CTS symptoms even after treatment
Recovery from Carpal Tunnel Syndrome
For helping people recover from Carpal Tunnel Syndrome (CTS), certain techniques like using a splint and adopting good hand practices play a big role. Therapists often use treatments like ultrasound, iontophoresis, and paraffin wax to lessen swelling and help with pain. However, studies on how much these treatments actually help have had mixed results. More detailed research is needed to fully understand how effective they are.
Other methods such as nerve-gliding exercises, massage, and trigger point release have shown promising results in improving muscle strength, reducing pain, and improving nerve function according to available studies. Physical or occupational therapists treating CTS patients should consider including these methods in their treatment plan.
Preventing Carpal Tunnel Syndrome
Carpal Tunnel Syndrome, or CTS, happens when the median nerve, which runs through the wrist, gets squeezed. Though doctors can’t pinpoint why this happens, they think it’s due to a combination of genetics, certain health problems, and environmental factors.
Common symptoms of CTS are pain, numbness, tingling, and occasionally weakness in the first three fingers and part of the fourth, nearest to the thumb. These symptoms might show up in one or both hands and could even travel up the arm. As a result, people with CTS could find everyday tasks such as buttoning clothes or turning doorknobs challenging because their hands might feel clumsy.
Women are more likely than men to have CTS, and people with jobs that require repetitive hand movements or the use of vibrating equipment have a higher risk of getting it. Certain health conditions can also increase the chances of developing CTS, such as diabetes, obesity, rheumatoid arthritis, thyroid problems, and also being pregnant.
Doctors can often diagnose CTS in patients who have mild symptoms without needing to carry out further tests. Those with unusual or intense symptoms may need electrical nerve tests which can help doctors understand how well the nerve and surrounding muscles are working.
Some of the typical first steps for treating CTS include wearing a wrist splint at night or getting a steroid injection in the wrist. In some instances, oral steroids might be prescribed. This could be the solution especially for pregnant women, as their symptoms will usually disappear after giving birth. Seeing a hand therapist could also be beneficial.
If the symptoms are severe or do not get better with these non-invasive measures, doctors may recommend surgery. This involves releasing the ligament over the wrist to create more room around the median nerve.
