What Is Carpal Tunnel Syndrome
Carpal Tunnel Syndrome (CTS) is a median entrapment neuropathy, that causes paresthesia, pain, numbness, and other symptoms in the distribution of the median nerve due to its compression at the wrist in the carpal tunnel. The pathophysiology is not completely understood but can be considered compression of the median nerve traveling through the carpal tunnel. It appears to be caused by a combination of genetic and environmental factors. Some of the predisposing factors include: diabetes, obesity, pregnancy, hypothyroidism, and heavy manual work or work with vibrating tools but not lighter work even if repetitive.
The main symptom of CTS is intermittent numbness of the thumb, index, long and radial half of the ring finger. The numbness often occurs at night, with the hypothesis that the wrists are held flexed during sleep. Recent literature suggests that sleep positioning, such as sleeping on one’s side, might be an associated factor. It can be relieved by wearing a wrist splint that prevents flexion. Long-standing CTS leads to permanent nerve damage with constant numbness, atrophy of some of the muscles of the thenar eminence, and weakness of palmar abduction.
Pain in carpal tunnel syndrome is primarily numbness that is so intense that it wakes one from sleep. Pain in electrophysiologically verified CTS is associated with misinterpretation of nociception and depression.
Conservative treatments include use of night splints and corticosteroid injection. The only scientifically established disease modifying treatment is surgery to cut the transverse carpal ligament.
- People with CTS experience numbness, tingling, or burning sensations in the thumb and fingers, in particular the index, middle fingers, and radial half of the ring fingers, which are innervated by the median nerve.
- Less-specific symptoms may include pain in the wrists or hands and loss of grip strength (both of which are more characteristic of painful conditions such as arthritis).
- burning sensations in the wrists or hands
- loss of grip strength
- Median nerve symptoms can arise from compression at the level of the thoracic outlet or the area where the median nerve passes between the two heads of the pronator teres in the forearm, but this is highly debatable. This line of thinking is an attempt to explain pain and other symptoms not characteristic of carpal tunnel syndrome. Carpal tunnel syndrome is a common diagnosis with an objective, reliable, verifiable pathophysiology, whereas thoracic outlet syndrome and pronator syndrome are defined by a lack of verifiable pathophysiology and are usually applied in the context of nonspecific upper extremity pain.
- Numbness and paresthesias in the median nerve distribution are the hallmark neuropathic symptoms (NS) of carpal tunnel entrapment syndrome. Weakness and atrophy of the thenar muscles may occur if the condition remains untreated
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Treatments
- Generally accepted treatments include: steroids either orally or injected locally, splinting, and surgical release of the transverse carpal ligament. There is no or insufficient evidence for ultrasound, yoga, lasers, B6, and exercise therapy.
- Early surgery with carpal tunnel release is indicated where there is clinical evidence of median nerve denervation or a person elects to proceed directly to surgical treatment. The treatment should be switched when the current treatment fails to resolve the symptoms within 2 to 7 weeks. However, these recommendations have sufficient evidence for carpal tunnel syndrome when found in association with the following conditions: diabetes mellitus, coexistent cervical radiculopathy, hypothyroidism, polyneuropathy, pregnancy, rheumatoid arthritis, and carpal tunnel syndrome in the workplace.
- The importance of wrist braces and splints in the carpal tunnel syndrome therapy is known, but many people are unwilling to use braces. In 1993, The American Academy of Neurology recommend a non-invasive treatment for the CTS at the beginning (except for sensitive or motor deficit or grave report at EMG/ENG): a therapy using splints was indicated for light and moderate pathology. Current recommendations generally don’t suggest immobilizing braces, but instead activity modification and non-steroidal anti-inflammatory drugs as initial therapy, followed by more aggressive options or specialist referral if symptoms do not improve.
- Many health professionals suggest that, for best results, one should wear braces at night and, if possible, during the activity primarily causing stress on the wrists.
- Corticosteroid injections can be effective for temporary relief from symptoms while a person develops a longterm strategy that fits their lifestyle. This treatment is not appropriate for extended periods, however. In general, local steroid injections are only used until other treatment options can be identified. For most surgery is the only option that will provide permanent relief.
- Scars from carpal tunnel release surgery. Two different techniques were used. The left scar is 6 weeks old, the right scar is 2 weeks old. Also note the muscular atrophy of the thenar eminence in the left hand, a common sign of advanced CTS. Release of the transverse carpal ligament is known as “carpal tunnel release” surgery. It is recommended when there is static (constant, not just intermittent) 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.
- One review of the evidence found good evidence for splinting, ultrasound, nerve gliding exercises, carpal bone mobilization, magnetic therapy, and yoga for people with carpal tunnel syndrome. However, a recent evidence based guideline produced by the American Academy of Orthopedic Surgeons assigned lower grades to most of these treatments.
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