FAQs on Carpal Tunnel Syndrome (CTS)

Carpal tunnel syndrome (CTS) is a common condition affecting the wrist and hand. Symptoms occur when the median nerve is squeezed inside the carpal tunnel of the wrist, which is called compressive neuropathy or nerve entrapment.

This syndrome is associated with occupations that require repeated use of the hands, such as assembly work or typing. The incidence of CTS is 1-3 people per 1,000, but is reported as high as 160 cases per 1,000 subjects in the U.K. However, in developing countries, such as Africa, CTS is quite rare.

What is the “carpal tunnel?”

The carpal tunnel is an opening of the wrist that leads to the hand. It is formed on one side with the bones of the wrist, and on the other side, the transverse carpal ligament. The median nerve passes through this tunnel into the hand, giving sensation to the fingers and thumb. In addition, the flexor tendons pass through this tunnel, and they are covered with a slippery material called the tenosynovium.

What causes CTS?

Any condition that causes the inside of the carpal tunnel to decrease, or the size of the tissues within the tunnel to increase, can lead to CTS symptoms. When the carpal tunnel cannot expand, it leads to abnormal pressure, and any increase in pressure results in reduced blood flow to the median nerve.

Without proper blood supply, the median nerve loses function. In addition, when the tenosynovium thickens due to inflammation, pressure builds in the carpal tunnel, and the median nerve is compressed. Fibroblasts form within the nerve and result in scar tissue, which is believed to produce feelings of numbness and pain in the hand.

What are the symptoms of carpal tunnel syndrome?

When a person develops CTS, the first symptoms include tingling and numbness of the fingers and hand. The initial symptoms are followed by a vague, dull pain. Many patients report that the hand feels like it is asleep, especially in the early morning hours.

Symptoms are often worse at night, because the wrist is often in a curled position during sleep. In the advanced stages of the disease, the muscles weaken, causing difficulty picking up things.

How is CTS diagnosed?

The doctor will begin your evaluation by obtaining a history of the problem and conducting a thorough physical examination. If there is a history of a traumatic wrist injury, x-rays may be taken to check for a fracture of one or more bones or dislocation. To evaluate median nerve function, the doctor will perform a nerve conduction velocity (NCV) test, which measures how fast the nerve impulses move through the median nerve.

What are the treatment options for CTS?

Carpal tunnel syndrome can be treated without surgery, for some patients. Depending on the severity of the condition, treatment options include:

  • Medications – The doctor may prescribe nonsteroidal anti-inflammatory drugs (NSAIDs), such as naproxen or ibuprofen.
  • Brace/splint – An immobilizing device, such as a brace or splint, can be used to keep the wrist aligned in a neutral position. This prevents compression of the medial nerve.
  • Corticosteroid injections – The doctor can inject a steroid near the median nerve or directly into the carpal tunnel, which will decrease inflammation and swelling. In a recent clinical study, three-month follow-up success rate was 77% with corticosteroid injections. In addition, 63% of patients had relief of pain at six-month follow-up.
  • Carpal tunnel release surgery – If symptoms are severe, either open or endoscopic surgery can be done to sever (release) the carpal ligament (band of tissue) and separate it from the median nerve. While both approaches are effective for chronic CTS, endoscopy offers quicker functional recovery.

Resources

Atroshi I, Gummesson C, Johnsson R, et al. (1999). Prevalence of carpal tunnel syndrome in a general population. JAMA, 282(2):153-8.

Lalonde DH (2014). Evidence-based medicine: carpal tunnel syndrome. Plastic Reconstructive Surgery, 133(5), 1234-1240. DOI: 10.1097/PRS.0000000000000092.

Mintalucci DJ & Leinberry CF Jr. (2012).Open versus endoscopic carpal tunnel release. Orthop Clin North Am, 43(4):431-7.

Pomerance J, Zurakowski D, & Fine I (2009). The cost-effectiveness of nonsurgical versus surgical treatment for carpal tunnel syndrome. J Hand Surg Am, 34(7):1193-2000.

Visser, L. H., Q. Ngo, et al. (2011). Long term effect of local corticosteroid injection for carpal tunnel syndrome: A relation with electrodiagnostic severity. Clinical Neurophysiology.