Carpal Tunnel Syndrome

What Is Carpal Tunnel Syndrome? What Causes Carpal Tunnel Syndrome?

Carpal Tunnel Syndrome (CTS) is associated by symptoms and signs, which are caused by compression of the median nerve travelling through the carpal tunnel. Carpal Tunnel Syndrome affects the hands since it is an upper limb neuropathy that results in motor and sensory disturbance of the median nerve.

The carpal tunnel is an anatomical compartment located at the base of the wrist. Nine flexor tendons and the median nerve pass through the carpal tunnel that is surrounded on three sides by the carpal bones that form an arch. The nerve and the tendons provide function, feeling, and movement to some of the fingers.

According to Medilexicon's medical dictionary:

Carpal Tunnel Syndrome is the most common nerve entrapment syndrome, characterized by paresthesias, typically nocturnal, and sometimes sensory loss and wasting in the median nerve distribution in the hand; often bilateral and affects women more than men; due to chronic entrapment of the median nerve at the wrist within the carpal tunnel.

CTS is one of the most common conditions affecting the nerves of the hand. It is estimated that almost 5% of women and 3% of men have CTS. Most cases of CTS develop in people who are between 45-64 years of age.

In 1854, Sir James Paget was the first to report median nerve compression at the wrist in a distal radius fracture. Following the early 20th century there were various cases of median nerve compression underneath the transverse carpal ligament. CTS was most commonly noted in medical literature in the early 20th century but the first use of the term was noted 1939. Physician Dr. George S. Phalen of the Cleveland Clinic identified the pathology after working with a group of patients in the 1950s and 1960s.

CTS is not a life-threatening condition, but it can negatively affect lifestyle if left untreated. In worst case scenarios, the median nerve can become severely damaged and result in total loss of movement within that hand.

What are the symptoms of Carpal Tunnel Syndrome?

A symptom is something the patient senses and describes, while a sign is something other people, such as the doctor notice. For example, drowsiness may be a symptom while dilated pupils may be a sign.

CTS sufferers experience numbness, tingling, or burning sensations in the thumb and fingers, particularly the index and middle fingers, which are innervated by the median nerve. Persons also experience pain in the hands or wrists and some report to have lost gripping strength. Pain develops in the arm and shoulder and swelling of the hand, which increases at night. The reason symptoms are worse at night may be related to the flexed-wrist sleeping position and/or fluid accumulating around the wrist and hand while lying flat.
Individuals may have problems using the affected fingers to carry out tasks that require high levels of manual dexterity, such as typing. In rare cases some experience dry skin, swelling or changes to the color of your skin in the affected hand.

What are the causes of Carpal Tunnel Syndrome?

Most cases of CTS are of unknown causes, or idiopathic. Carpal Tunnel Syndrome can be associated with any condition that causes pressure on the median nerve at the wrist. Some common conditions that can lead to CTS include obesity, hypothyroidism, arthritis, diabetes, and trauma. Tendon inflammation resulting from repetitive work, such as uninterrupted typing, can also cause carpal tunnel symptoms.

Other causes of this condition include intrinsic factors that exert pressure within the tunnel, and extrinsic factors, pressure exerted from outside the tunnel, which include benign tumors such as lipomas, ganglion, and vascular malformation.

CTS is found mostly in the working adult population, and for this reason, it is very likely to be associated with the workplace whether or not it is caused by the work itself. When a single muscle performs more than one task, for example twisting and flexing of the wrist muscles, the increased muscle load plays an important role in the development of musculoskeletal disorders.

Additionally, CTS seems to run in families. About 25% of people with the condition have a close relative who also has CTS. Exactly how and why the condition is spread through families is not fully understood.

Diagnosing Carpal Tunnel Syndrome

A common test that is used to help diagnose CTS involves tapping the wrist lightly to see if it produces a tingling feeling or numbness in the affected hand. Another test involves flexing the wrist for 60 seconds to see if this produces pain, numbness or tingling in the hand.

These tests are defined more specifically as three separately named examinations:

First, Phalen's maneuver is performed by flexing the wrist gently as far as possible, then holding this position and awaiting symptoms. A positive test is one that results in numbness in the median nerve distribution when holding the wrist in acute flexion position within 60 seconds. The quicker the numbness starts, the more advanced the condition. Phalen's sign is defined as pain or paresthesias in the median-innervated fingers with one minute of wrist flexion. Only this test has been shown to correlate with CTS severity when studied prospectively.

Second, Tinel's sign is a way to detect irritated nerves. As mentioned above, Tinel's is performed by lightly tapping the skin over the flexor retinaculum to elicit a sensation of tingling or "pins and needles" in the nerve distribution. Tinel's sign (pain and/or paresthesias of the median-innervated fingers with percussion over the median nerve) is less sensitive, but slightly more specific than Phalen's sign.

Finally, Durkan test, or carpal compression test, is performed by applying firm pressure to the palm over the nerve for up to 30 seconds to elicit symptoms as a means of CTS diagnosis.

What are the treatment options for Carpal Tunnel Syndrome?

Generally accepted treatments may include splinting or bracing, steroid injection, activity modification, physical or occupational therapy (controversial), regular massage therapy treatments, medications, and surgical release of the transverse carpal ligament.

Those whose occupations are aggravating the symptoms should modify their activities. For example, computer keyboards and chair height may need to be adjusted to optimize comfort.

Wearing a wrist splint at night should help to reduce the compression on your median nerve and help to improve your symptoms. However, it may take up to eight weeks for you to fully notice the benefits.

Several types of medications have been used in the treatment of carpal tunnel syndrome. Vitamin B6, has been reported to relieve some symptoms of carpal tunnel syndrome, although it is not known how this medication works. Nonsteroidal anti-inflammatory drugs can also be helpful in decreasing inflammation and reducing pain. These medications should be taken with food, and abdominal symptoms should be reported to the doctor. Corticosteroids can be given by mouth or injected directly into the involved wrist joint. They can bring rapid relief of the persistent symptoms of CTS.

Surgery is an option, although seldom implemented. Release of the transverse carpal ligament is known as carpal tunnel release surgery. It is recommended when there is constant numbness, muscle weakness, or atrophy, and when night-splinting no longer controls intermittent symptoms. In general, milder cases can be controlled for months to years, but severe cases are unrelenting symptomatically and are likely to result in surgical treatment.

Preventing Carpal Tunnel Syndrome

Periodic resting and range of motion stretching exercise of the wrists can actually prevent the symptoms of carpal tunnel syndrome that are caused by repetitive overuse.

Healthy habits like avoiding repetitive stress, practicing healthy work habits like using ergonomic equipment (wrist rest, mouse pad), taking proper breaks, using keyboard alternatives (digital pen, voice recognition and dictate) and early passive treatment like taking turmeric (anti-inflammatory), omega-3 fatty acids, and B vitamins can limit the occurrence of CTS.