What is Carpal Tunnel Syndrome?
Carpal tunnel syndrome explained by Denver, Golden, Aurora, Boulder, Broomfield, Jefferson, and Littleton Colorado’s top pain doctors
Carpal tunnel syndrome occurs when the median nerve becomes compressed at the wrist. The median nerve is the primary nerve for the upper limbs and is located in the forearm. It originates in the brachial plexus, and runs down along the medial side of the arm to the palm of the hand. The median nerve transmits sensory sensations from the palm side of the thumb and all fingers except the small finger. It also plays a contributory role in the motor innervation for a number of small muscles within the hand that control the fingers and thumb. On the palm side of the wrist is a passageway that is constructed of ligaments and bone, providing a tunnel through which the median nerve can feed into the hand. The passageway itself is rigid and very narrow, as its function is to protect the median nerve. Due to the passageway’s narrow structure, the median nerve is at risk for entrapment or compression injuries.
When the median nerve becomes entrapped, compressed, and irritated it is likely to become inflamed, causing symptoms of paresthesia or “pins and needles” (i.e., tingling, prickling, or burning sensations), weakness, numbness, or pain in the area of the hand and wrist. These symptoms of pain or discomfort are broadly categorized as carpal tunnel syndrome. In some cases of carpal tunnel syndrome, patients report that their symptoms of pain or discomfort can radiate up the forearm from the wrist.
Causes of Carpal Tunnel Syndrome
The primary etiology for carpal tunnel syndrome is linked to the nerve that runs down the forearm, along the carpal tunnel passageway. This nerve is known as the median nerve. It is believed that the pain and discomfort arises as a result of the median nerve becoming entrapped or compressed within the carpal tunnel as the result of a variety of environmental factors. This pressure irritates the nerve causing it to become inflamed.
Several environmental factors have been found to contribute to the onset of symptoms of carpal tunnel syndrome. In particular, individuals who have sustained either acute or chronic trauma to the wrist or forearm (particularly the medial surface) are at a significantly higher risk for developing pain and discomfort associate with carpal tunnel syndrome. Direct or chronic trauma to the area increases the risk for irritation, swelling, and even nerve damage. Environmental conditions at work also account for a large portion of cases of carpal tunnel syndrome. Primarily, individuals who spend more time engaged in forceful exertion, activities involving hand strength, and using vibrating tools are at a much higher risk for developing carpal tunnel.
There is also some data to suggest that patients who develop carpal tunnel syndrome were genetically predisposed to developing this condition. For instance, it may be that variations in the size of the passageway encasing the median nerve can account for why some patients develop symptoms of carpal tunnel syndrome when others do not, despite both being under generally similar environmental conditions. Other individual risk factors that are found to occur more frequently among individuals who have developed carpal tunnel syndrome include diabetes, obesity, hypothyroidism, dysregulated pituitary gland, hypothyroidism, and rheumatoid arthritis. Additionally, owing to the increase in fluid retention, women who are pregnant are more likely to develop symptoms related to carpal tunnel syndrome.
Treatments for Carpal Tunnel Syndrome
There are several treatment options available to help alleviate the discomfort of carpal tunnel syndrome, and depend on the severity of the pain, the chronicity of the condition, the patient’s work environment, the degree of debilitation, and whether the patient has attempted any other forms of intervention.
For mild to moderate cases of carpal tunnel syndrome, where the patient is generally able to maintain daily activities, it may be recommended that patients wear an immobilizing brace or a splint on the wrist at night and during activities that place stress on the wrist.
Some patients with mild to moderate symptoms of carpal tunnel syndrome opt for corticosteroid injections. These have been shown to be an effective intervention option for the short-term management of pain. Though it is not generally recommended that patients rely on corticosteroid injections for the long-term management of pain or discomfort associated with carpal tunnel, these injections are highly effective for temporarily reducing the underlying inflammation that causes pain, allowing patients the time to develop a long-term plan.
Some recent evidence has emerged suggesting that the beneficial effects of corticosteroid injections may be longer- lasting than originally believed. More specifically, using survivor analysis, a recently conducted survey indicated that up to 33% of individuals who had received corticosteroid injections for the relief of discomfort and pain associated with carpal tunnel syndrome did not attempt to receive any additional treatment for these symptoms at a two-year follow-up.
For individuals who do not wish to receive injections, non-steroid anti-inflammatory medications are available and have shown some effectiveness for relieving pain associated with carpal tunnel syndrome. Given their anti-inflammatory properties, these medications reduce the swelling that is believed to be the primary source of the pain. Additionally, patients may be prescribed a diuretic, to be taken orally, that will help reduce the amount of fluid retention and thereby decrease swelling that may be placing pressure on the median nerve.
For moderate to severe cases of carpal tunnel syndrome, the only effective permanent treatment option available is surgery. This is typically recommended once patients report that their pain and discomfort are no longer intermittent, and that they are now experiencing unrelenting symptoms that have begun to have a significant impact on their ability to function on a daily basis. This procedure, which is also known as carpal tunnel decompression surgery, involves releasing the tension on the ligaments within the carpal tunnel. This can be performed using either traditional surgical openings or through an endoscopic approach. Both have reported very high success rates. In fact, recent data suggests that up to 90% of patients undergoing surgical correction for carpal tunnel syndrome were able to return to their original line of work.
Carpal tunnel syndrome is a common pain condition that is caused by the entrapment or compression of the median nerve, which is the nerve that runs down the medial surface of the forearm, through the carpal tunnel, to the palm of the hand. While the precise pathophysiology is still somewhat unclear, risk for developing carpal tunnel syndrome is generally impacted by genetic, individual, and environmental factors.
There are several treatments available for patients suffering from the pain and discomfort of carpal tunnel syndrome. Patients are encouraged to speak with a physician about their condition in order to identify the best treatment plan for the management of their pain.
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