Carpal tunnel syndrome (CTS) represents a collection of signs and symptoms resulting from the compression or pinching of the median nerve as it passes through the carpal tunnel at the wrist. In this overview, you will see why CTS can be a challenging ailment to diagnose and treat.
SYMPTOMS: Numbness, tingling, and pain. Less commonly, burning and/or sharp pain in the index to the thumb-side half of the fourth finger, palm-side only. Loss of grip strength (such as unscrewing a jar) may occur but usually later in the course of the condition.
PATHOPHYSIOLOGY: Compression of the median nerve inside the bony carpal tunnel occurs when the pressure inside the tunnel increases, often due to overuse with subsequent swelling. There are multiple epidemiologic factors including genetic, medical, social, vocational, avocational, and demographic with a complex interplay between some or all these factors. However, definitive causative factors remain obscure and unclear in many cases.
EPIDEMIOLOGY: About one to three people per every 1,000 will develop CTS in a given year, and estimates show about 50 people per 1,000 currently live with CTS in the general population. However, the incidence may rise as high as 150 cases per 1,000 subjects per year, with prevalence rates greater than 500 cases per 1,000 subjects in certain high-risk groups. The incidence and prevalence is similar in developed countries like the United States, the United Kingdom, and the Netherlands, but CTS is almost unheard of in some developing countries. The female-to-male ratio for CTS is three-to-ten females to one male. Carpal tunnel syndrome seems to peak at age 45-60 years old with only 10% of CTS patients under the age of 31. The condition is not fatal, but if left untreated, severe cases can lead to complete, irreversible median nerve damage and a loss of much hand function.
CLINICAL PRESENTATION: A patient’s history is often more valuable than the physical examination when it comes to CTS. Patients may report the above-listed symptoms, which may worsen at night and interrupt sleep. Symptoms may also increase in intensity during activities like driving, crocheting, and painting. Frequently, CTS affects both hands, but it’s usually worse in the dominant hand. Patients may have difficulty “mapping” their symptoms well and may feel numbness, tingling, pain, and/or weakness in the whole arm and/or forearm. It’s often prudent to look for additional compression elsewhere in the course of the median nerve in the neck, shoulder, and/or elbow. Less commonly, the patient may experience whole hand hot/cold sensitivity with color changes and/or sweating, which may indicate autonomic nervous system involvement. The use of CTS questionnaires can help diagnose and track progress during care. This discussion will continue next month – stay tuned!