Carpal tunnel syndrome causes, symptoms, and treatments

What is carpal tunnel syndrome?

Carpal tunnel syndrome (CTS) is one of the most common hand and wrist condition which is caused by pressure on the median nerve in the carpal tunnel of the wrist. The carpal tunnel is a narrow passageway surrounded by bones and ligaments on the palm side of the wrist. When the median nerve is compressed, symptoms can include numbness, tingling and weakness of the hands and fingers. (https://www.mayoclinic.org/diseases-conditions/carpal-tunnel-syndrome/symptoms-causes/syc-20355603) 

What causes CTS?

The pain in CT is due to excess pressure in the wrists and median nerve. Inflammation can cause swelling which could be due to underlying health conditions such as:

• Diabetes
• Thyroid dysfunction
• Fluid retention from pregnancy or menopause
• High blood pressure
• Autoimmune disorders such as rheumatoid arthritis 
• Fractures or trauma to the wrist
• Ganglion/cysts 

CTS can be made worse if the wrist is overextended repeatedly which contributes to swelling and compression of the median nerve. This maybe the result of:

• Positioning of the wrist while use of computer mouse and keyboard
• Prolonged exposure to vibration from handheld power tools
• Repetitive movements of the wrists such as typing or playing piano

Who is at risk of getting CTS?

Women are three times more likely than men between 30-60 years to get CTS. Lifestyle factors which may increase the risk of getting CTS include smoking, high salt intake, sedentary lifestyle and high BMI. Jobs that involve repetitive wrist movement like:

• Manufacturing
• Assembly line works
• Keyboard occupations
• Construction work
• Heavy weight lifting  

What are the symptoms of CTS?

The symptoms may usually come on slowly starting in one or both hands at night and go away during the day. As symptoms get worse, they may last longer and come more often. Symptoms may include:

• Numbness, tingling, burning pain or weakness in fingers especially thumb, index and middle fingers.
• Shock-like sensation that shoots in the thumb, index and middle finger, sometimes some of the ring finger.
• Pain or tingling that may travel upwards to forearm or shoulder.
• Trouble holding onto things because of hand weakness, numbness or not knowing where the hand is in space.
• sleeping with flexed wrists or positions which put pressure on the wrists at night can worsen symptoms.

How is CTS diagnosed?

A positive Tinel`s sign or Phalen`s test prompts the physician to rule out other diagnosis of wrist pain. An X-ray may reveal arthritis or fractures around the wrist. An ultrasound or MRI may show median nerve compression and its underlying cause. Lab testing like blood tests may reveal diabetes which may contribute to peripheral neuropathy. 

Nerve conduction velocity test provides some of the strongest evidence to detect median nerve compression at the carpal tunnel. Electromyography can support the findings of conduction velocity test by objectively evaluating muscle function innervated by the median nerve.

What is the treatment of CTS?

Treatment will depend on symptoms and how far the condition has progressed. The underlying cause of CTS is addressed for e.g. rheumatoid arthritis or diabetes, along with the symptoms of CTS. 

• Medication like NSAIDs (Ibuprofen, Naproxen) can help reduce pain and inflammation. A steroid injection in the wrist can be given which is a potent anti-inflammatory and can bring pain and swelling down. 
• Activity modification after having the diagnosis is vital to prevent irreversible nerve degeneration. Taking frequent breaks, modification of handheld tools and work station dynamics to minimize the damaging impact on the condition. 

If none of the above treatments provide long term relief, surgery is offered. Depending on the severity of symptoms, recovery from surgery can be fast or it can take months to get symptomatic relief. The transverse carpal ligament is cut by open release or endoscopic approach. Benefits and risk of complications are discussed with the patient before choosing procedure.

Physical therapy research supports the use of therapeutic ultrasound, shockwave therapy and acupuncture. Wrist stretching, strengthening exercises of hand and nerve glides have also been proven to be effective in the management of CTS. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7117610/) 

Bracing or splinting helps to prevent the wrist from extreme range of movement which puts strain and pressure on median nerve. Wearing a brace can be extremely helpful while working on keyboard or during night when the pain is usually worse. 

Is CTS preventable?

There are no proven strategies to prevent CTS, however following methods can reduce the stress on hands and wrists. 

• Reduce your force and relax your grip – if your work involves a cash register or keyboard, for example, hit the keys softly.
• Take short frequent breaks – gently stretch your wrists and hands periodically. Alternate tasks when possible. This is important if you are using equipment that vibrate for e.g. drillers or applying force repetitively e.g. operating fork lifts or manual labor tasks.
• Watch your joints and body posture – neutral wrists parallel to the floor with forearms well supported and elbows at 90 degrees is ideal for desk-based jobs. Occupational therapy can advise on work station modifications for joint protection.
• Change computer mouse – using a vertical instead of a horizontal mouse can help avoid excessive wrist extension and promote neutral wrist position which minimizes pressure and strain on wrist structures. 
• Keep the extremities warm especially in cold weather where they are more prone to cold and stiffness. (https://www.mayoclinic.org/diseases-conditions/carpal-tunnel-syndrome/symptoms-causes/syc-20355603)