Carpal tunnel syndrome

Carpal tunnel syndrome is a condition in which a person experiences pain and swelling in the hand due to increased pressure on a nerve (median nerve) inside the wrist.

The carpal tunnel is a narrow passageway in your wrist surrounded on three sides by the wrist bones (carpals) and on the top side with a ligament called the transverse carpal ligament. The tunnel is only a few inches wide and has no space to stretch or widen. 

The median nerve is a thick nerve that starts from the neck and passes into the hand through the carpal tunnel. It controls the muscles under the thumb and is responsible for providing sensations in the thumb along with the index, middle and ring fingers. 

In case any of the tissues surrounding the carpal tunnel swell, the whole tunnel narrows down and since there isn’t much space inside the tunnel, it increases the pressure on the median nerve. As a result, the person starts to experience the symptoms of carpal tunnel syndrome. 

The symptoms of carpal tunnel syndrome develop gradually, usually starting with the dominant hand and showing up first at night. Eventually, the person starts to notice the symptoms during day time too. 

The following are some of the symptoms of carpal tunnels syndrome:

• Wrist pain, either in one or both hands. The pain may go up to the elbows
• Numbness in the palm, especially the thumb, index finger, and middle and ring fingers
• Difficulty gripping objects
• Weakness in hands
• Feeling like you want to shake your hands out on waking up
• Tingling in hands while working or holding something
• Problems in moving fingers or coordinating finger movements

When left untreated, the condition can cause the muscles under the thumb to waste away and the person may stop having any hot or cold sensations in their hands.

Carpal tunnel syndrome can occur due to an injury, sprain or fracture in the wrist. Some other causes and risk factors for carpal tunnel syndrome include:

• Repeated movements of the wrist like working in an office or an assembly line. 
• Swelling in the wrist due to hormonal changes in pregnancy and menopause. The wrist structures may enlarge in some women after menopause, putting pressure on the median nerve
• Being born with a smaller space inside the carpal tunnel.
• Health conditions including rheumatoid arthritis, diabetes, hypothyroidism, and gout 
• Older age
• Alcoholism
• Dialysis
• Rarely, tumours in the wrist
• After a mastectomy (surgery to remove breast tissue), some women develop oedema in the lymphatic system. This oedema may spread to hands and increase pressure on the median nerve

Women, especially those aged 30 and 60, are more at risk than men.

Not all causes of carpal tunnel syndrome are preventable. However, you can reduce your risk of developing the condition by taking the following things into consideration:

• Avoid repetitive wrist movements whenever you can.
• At work:
  • Use correct posture and wrist positioning to not put extra strain on your wrist
  • Take rest in-between 
  • Do some stretching exercises before and after work
  • Stop working if you start to feel pain or tingling in your wrist
  • If possible, jobs that need repeated wrist movement should be rotated among employees
• Avoid sleeping on your wrist
• Opt for tools that are designed to reduce wrist injury
• Keep your hands warm by wearing fingerless gloves

Carpal tunnel syndrome is diagnosed through physical examination. Your doctor will look for the symptoms of the disease and check for any mechanical restriction in the soft tissues of your hands and fingers. He/she will conduct the following tests: 

• Carpal compression test: In this test, the doctor will put pressure on the carpal tunnel area of your wrist for about 30 seconds. If you have carpal tunnel syndrome, you will experience pain and other symptoms of the condition.
• Phalen’s test: In this test, you will be asked to touch the back of your palms with each other, kind of like a reverse prayer pose, and hold for a minute. If you have carpal tunnel syndrome, you would notice increased tingling.
• Nerve conduction velocity test: Nerve conduction velocity test is used to check the speed with which an electrical impulse can pass through the nerves of all four limbs. 
• Electromyography: This test checks for electrical activity in the muscles, to rule out nerve dysfunction, muscle dysfunction or a problem in the communication between nerves and muscles.
• Scans: An X-ray may be done to rule out fractures, arthritis, and conditions like diabetes that can damage nerves. Ultrasound or MRI may also be done to get a clear picture of your median nerve and to check the soft tissues in your wrist.
• Hoffmann-Tinel sign: In this test, the doctor will tap over your carpal tunnel to see if you experience any pain or tingling.

Since carpal tunnel syndrome gets worse over time, it is best to start the treatment as early as possible to stop the progression of the disease. Treatment options include:

• Nonsurgical methods: Your doctor will ask you to avoid repetitive movements of the wrist as the movements could increase the pain and other symptoms. He/she may suggest that you:
  • Avoid sleeping on your wrist.
  • Wear a splint to help keep your wrist stable
  • Place your keyboard at a height to reduce flexing of your wrists. An occupational therapist may help you deal with the daily movements as per your job
  • Use hot and cold compress to relieve pain
  • Take nonsteroidal anti-inflammatory drugs (NSAIDs) to reduce swelling and pain

The doctor may also inject corticosteroids into your wrist or ask you to take them orally to reduce compression on the nerve. 

• Surgery: Surgery is the only definitive treatment for carpal tunnel syndrome. However, it is suggested when the patient does not respond well to any non-surgical treatment methods. About one-third of all people with carpal tunnel syndrome need surgery. In this surgery, the doctor cuts the transverse carpal ligament that covers the top of the carpal tunnel to release pressure on the median nerve. It is a minor procedure that can either be done with:
  • Open surgery: In this procedure, the surgeon will make one large cut in the wrist to perform the operation
  • Endoscopic surgery: In this procedure, the surgeon will make a few tiny cuts into your wrist to insert an endoscope (small flexible rod with a camera) and surgical instruments inside your wrist.

The surgery is done under local anaesthesia and you will not need an overnight stay.