What is carpal tunnel syndrome?
Carpal tunnel syndrome (CTS) is a common condition that affects the hands and arms. It can cause pain, numbness and a tingling sensation, amongst other symptoms.
It happens when the main nerve in your hand (the median nerve) is squeezed within the carpal tunnel, a narrow channel on the palm side of your wrist.
There are a number of factors which can cause carpal tunnel, one of the most common being repetitive hand movements. Regardless of the cause, in most cases it is possible to relieve the symptoms when the correct treatment is given.
Common signs and symptoms of carpal tunnel syndrome
Symptoms of carpal tunnel usually begin gradually with the first symptoms often being numbness or tingling in your thumb, index and middle finger. The condition can also cause pain in the wrist and in the palm of your hand.
Common carpal tunnel syndrome symptoms include:
- Tingling or numbness.Initially, these sensations may come and go, but as time goes on the feeling may become constant. Usually the thumb, index, middle or ring fingers are affected bringing on a sensation that some describe as being like an electric shock. If you are suffering from these symptoms, you may notice that they occur more often during certain activities, such as driving, using a phone or reading the newspaper. It may be severe enough to disturb your sleep and it can also travel up the arm. People dealing with CTS symptoms may frequently feel the need to shake their hands as if to shake out the sensations.
- This is another effect of CTS and can be severe enough that it causes you to drop things. The weakness tends to either be related to the feeling of numbness in the hand or a weakness in the muscles of the thumb which are controlled by the median nerve.
Common causes of CTS
Pressure on the median nerve is the cause of CTS. This major nerve runs from your forearm down through a channel in your wrist (the carpal tunnel) and into your hand. The purpose of the nerve is to provide feeling to the palm side of your thumb and fingers, except the little finger. It also supports motor function through nerve and muscle control.
When the median nerve gets compressed within the carpal tunnel, the symptoms mentioned earlier begin to arise. A fractured wrist can cause the carpal tunnel to become narrower, irritating the median nerve. Swelling from inflammatory conditions, such as rheumatoid arthritis can also compress the media nerve.
Carpal tunnel isn’t necessarily related to one single cause. In some cases, multiple factors can be considered risks:
- Anatomical factors. Physical issues that can affect the space within the carpal tunnel are known to cause CTS. These could be problems such as a fractured wrist, bone disorders and just having small carpal tunnels (common in women).
- Being female.The condition is more common in women and the reason is thought to be the smaller size of the carpal tunnels in woman relative to men.
- Nerve-damaging conditions.Illnesses that are associated with nerve damage, such as diabetes, can put you at risk of CTS.
- Inflammatory conditions.Issues such as rheumatoid arthritis, can cause inflammation in your wrist and result in pressure on your median nerve.
- Being obese can greatly increase your likelihood of developing CTS.
- Fluid retention. Increased bodily fluids can result in pressure within your carpal tunnel. An example of when this might occur is during pregnancy and the menopause. When carpal tunnel is associated with pregnancy, it usually goes away on its own after the pregnancy.
- Other medical conditions.Thyroid disorders and kidney failure are thought to increase your chances of developing CTS.
- Your occupation.Working with vibrating tools or any job that involves repetitive flexing of the wrist may put too much pressure on the median or exacerbate existing CTS symptoms. However, it has still not been proven that these risks are direct causes of CTS.
It is also thought that computer use may be a factor for developing CTS, but so far there has not been enough evidence to confirm this.
After evaluating your medical history and asking you questions, your doctor will conduct a physical examination to test the strength of the muscles in your hand and the feeling in your fingers. Flexing the wrist or putting pressure on the nerve can be enough to trigger symptoms.
After an initial examination, your doctor may also refer you for any of the following tests:
- X-ray – to exclude other common causes of wrist pain, such as arthritis or a fracture.
- Electromyogram (EMG) – to measure the tiny electrical discharges that are produced by your muscles. The test involves the insertion of a thin-needle electrode into your muscles to detect electrical activity. This type of test can help to rule out other conditions and muscle damage.
- Nerve conduction study– another test that can help to diagnose your condition and rule out others. It involves the use of two electrodes taped to the skin to measure electrical pulses in the nerves.
The doctor will diagnose CTS based on your symptoms and clinical examination. The sooner CTS is treated, the better. If early intervention takes place, non-surgical treatments may be effective. If unsuccessful or not appropriate, surgery is an alternative.
At first, non-surgical treatments such as wearing a wrist splint at night and taking over-the-counter painkillers are usually recommended. The doctor may also inject a strong anti-inflammatory steroid into the carpal tunnel for temporary relief of symptoms.
- Wrist splinting.A splint that keeps your writs in a certain position during sleep can help to reduce symptoms. This can be especially helpful in pregnant women.
- Nonsteroidal anti-inflammatory drugs (NSAIDs).NSAIDs, such as Brufen may provide short term symptom relief but are not shown to improve the condition itself.
- An injection of a steroid, such as cortisone can help to decrease inflammation, in turn relieving the pressure on the median nerve. The injection may be done under ultrasound guidance. Oral medication is an option but is thought to be less effective than injections.
If other conditions are causing CTS (such as arthritis), then treating the condition should help to reduce symptoms, although this is still unproved.
If symptoms of carpal tunnel syndrome do not respond to medical treatments, your doctor may decide to surgically release the pressure on the carpal tunnel and the contained median nerve — a procedure termed as carpal tunnel release. There are two techniques which can be performed:
- Endoscopic surgery.This is where telescope-like device with a tiny camera attached to it (endoscope) is used to look inside your hand while your surgeon makes a cut in the ligament via small cuts in the hand or wrist.
- Open surgery.During open surgery, your surgeon will make an incision in the palm of your hand to access the carpal tunnel and cut the ligament.
As with all surgery, there are risks associated. These include:
- Incomplete release of the ligament
- Injuries to the nerves or veins
After the surgery, your wrist will be wrapped in a bandage, and stitches removed after about two weeks. You’ll experience some discomfort and temporary numbness but this usually goes away in about 24 to 72 hours.
The answer to how long you need to rest your hand varies. In general, recovery is faster with the endoscopic approach, allowing you to return to work sooner. Regardless, heavy lifting or other major activities should best be avoided for at least 4 to 6 weeks to enable the wound to heal. You can expect the healing in as little as three weeks if you don’t put much strain on your wrist.