Carpal tunnel syndrome

The carpal tunnel is a narrow, rigid passageway surrounded by bones and ligaments on the palm side of the hand. Carpal tunnel syndrome is caused by pressure on the median nerve. The nerve provides sensory and motor functions to the thumb and three middle fingers. If the nerve becomes compressed or irritated, you may experience symptoms.

It is a progressive condition that can worsen, however, if you receive proper treatment, you can usually relieve the symptoms and restore your wrist and hand function.

Symptoms

Carpal tunnel syndrome may cause the following symptoms:

• Tingling, numbness or burning pain. This feeling typically occurs in the thumb and index, middle or ring fingers, but generally not the pinkie. These symptoms may be worse at night.
• Shock-like sensation. You may experience an electric shock sensation in the impacted fingers. The feeling may travel from the forearm into the fingers and can occur while holding an object, such as a steering wheel, phone or newspaper, or may even wake you from sleep.
• Weakness. You may experience weakness in the hand and thumb which could lead to dropping things or clumsiness in the hand.

In most cases, these symptoms will typically start gradually and worsen over time.

Risk factors

There have been a number of risk factors associated with carpal tunnel syndrome. While not all may directly cause the ailment, they may increase the risk of irritation or damage to the median nerve. These factors include:

• Previous injury or arthritis. A wrist fracture or dislocation, or arthritis that impacts the small bones in the wrist, can alter the space within the carpal tunnel and put pressure on the median nerve.
• Gender. Women are three times more likely than men to develop carpal tunnel syndrome which may be due to the carpal tunnel area being relatively smaller in women than in men.
• Other medical and health conditions. Conditions that are associated with carpal tunnel syndrome include pregnancy, diabetes, rheumatoid arthritis, thyroid disorders, obesity, menopause, kidney failure and lymphedema.
• Repetitive hand use. Doing the same hand and wrist motions over a prolonged period of time can aggravate the tendons in the wrist and lead to swelling that puts pressure on the nerve.

Diagnosing carpal tunnel syndrome

Your hand specialist will talk with you about what symptoms you’ve been experiencing and conduct a physical examination of your hand and wrist. If your specialist believes further testing is needed, they may order some of the following tests:

• X-ray. While an X-ray will not diagnose carpal tunnel syndrome, it may be done to exclude other causes of wrist pain, such as arthritis or fracture.
• Ultrasound. This will get a good picture of the bones and nerves in your wrist to help determine if the nerve is being compressed.
• Electromyography. This test can identify if there is any damage to the muscles controlled by the median nerve by measuring the tiny electrical discharges produced in the muscle.
• Nerve conduction study. In this study, two electrodes are placed on the skin and a small shock is passed through the median nerve to see if the electrical impulses are slowed in the carpal tunnel.

Treating carpal tunnel syndrome

Your hand specialist will discuss your options and develop a treatment plan made for you. If your condition is diagnosed early, some nonsurgical methods may help improve the condition, including splinting your wrist at night, taking breaks during the day to rest your hand, using nonsteroidal anti-inflammatory drugs (NSAIDs) or injecting a corticosteroid into the carpal tunnel.

If you aren’t responding to non-surgical options or if your symptoms are severe, your wrist specialist may recommend surgery. Surgery relieves pressure by cutting the ligament pressing on the median nerve and can be performed two different ways:

• Endoscopic surgery. During this minimally invasive procedure, your surgeon will use a device with a tiny camera attached to an endoscope to see inside the carpal tunnel. Your surgeon will make one or two small incisions in the hand or wrist to cut the ligament.
• Open surgery. An incision will be made in the palm of the hand over the carpal tunnel and cuts through the ligament to free the nerve.

Endoscopic surgery is less invasive and may result in less pain and a quicker recovery than open surgery. Your surgeon will develop and discuss your treatment plan based on your specific condition.