What is Carpal Tunnel Syndrome?
Carpal tunnel syndrome (CTS), or median neuropathy at the wrist, is a medical condition in which the median nerve is compressed at the wrist, leading to paresthesia, numbness and muscle weakness in the hand. Most cases of CTS are idiopathic (without known cause); genetic factors determining most of the risk, and the role of arm use and other environmental factors are disputed.
What are the symptoms of the disease?
Night symptoms and waking at night are the hallmark of this illness. Many people who have carpal tunnel syndrome gradually increase symptoms over time. The first symptoms of CTS may appear while sleeping that typically include numbness and paresthesia (a burning and tingling sensation) in the thumb, index and middle fingers, although some patients may experience symptoms in the palm as well. These symptoms appear at night because people tend to bend their wrists while sleeping, which further compresses the carpal tunnel.
Patients may note that they “drop things”. It is unclear if carpal tunnel syndrome creates problems holding things, but it does decrease sweating, which decreases friction between an object and the skin.
- In early stages of CTS individuals often mistakenly blame the tingling and numbness on restricted blood circulation. They may also be at ease and accepting of the symptoms and believe their hands are simply “falling asleep”.
- In chronic cases, there may be wasting of the thenar muscles (the body of muscles which are connected to the thumb), weakness of palmer abduction of the thumb (difficulty bringing the thumb away from the hand) unless numbness or paresthesia, are among the predominant symptoms, it is unlikely the symptoms are primarily caused by carpal tunnel syndrome. In effect, pain of any type, location, or severity with the absence of significant numbness or paresthesia is not likely to fall under the diagnosis.
What are the causes of the disease?
Most cases of CTS are idiopathic. CTS is sometimes associated with trauma, pregnancy, multiple myeloma, amyloidosis, rheumatoid arthritis, acromegaly, mucopolysaccaridoses, or hypothyroidism.
- Genetic: The most important risk factor for carpal tunnel syndrome are structural and biological rather than environmental or activity related. The strongest risk factor is risk predisposition.
- Work related: The relationship between work and CTS is controversial. Some speculate that carpal tunnel syndrome is provoked by repetitive grasping and manipulating activities, and that the exposure can be cumulative. It has also been stated that symptoms are commonly exacerbated by forceful and repetitive use of the hand and wrists in industrial occupations, but it is unclear if this refers to pain (which may not be due to carpal tunnel syndrome) or the more typical numbness symptoms.
- Psychosocial factors: Studies have related activity-related upper extremity pain with psychosocial and social factors, but most such pains are nonspecific but commonly mislabeled as carpal tunnel syndrome.
- Fractures of one of the arm bones
- Dislocation of one of the carpal bones of the wrist
- Strong blunt trauma to the wrist or lower forearm, incurred for example by using arm extremity to cushion a fall or protecting oneself from falling heavy objects
- Electrical burns may cause acute carpal tunnel syndrome
- Deformities from abnormal healing of old bone fractures
How is it diagnosed?
The reference standard for the diagnosis of carpal tunnel syndrome is electro physical testing. Patients with intermittent numbness in the distribution of the median nerve and positive Phalen’s and Durkan’s tests, but normal electro physical testing have at worst very mild carpal tunnel syndrome. A predominance of pain rather than numbness is unlikely due to be due to carpal tunnel syndrome no matter the result of electro physical testing. Clinical assessment by history taking and physical examination can support a diagnosis of CTS.
- 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 is.
- Tinel’s sign, a classic, though less specific test is a way to detect irritated nerves. Tinel’s is performed by lightly tapping the area over the nerve to elicit a sensation of tingling or “pins and needles” in the nerve distribution.
- Durkan test, carpal compression test, or applying firm pressure of the palm over the nerve for up to 30 seconds to elicit symptoms has also been proposed.
What are the treatments?
There have been numerous scientific papers evaluating treatment efficacy in CTS. It is important to distinguish treatments that are supported in the scientific literature from those that are advocated by any particular device manufacturer or any other party with a bested financial interest. Generally accepted treatments, as described below, may include splinting or bracing, steroid injection, activity modification, physical or occupational therapy (controversial), medications, and surgical release of the transverse carpal ligament.
- A wrist splint: It helps limit numbness by limiting wrist flexion. Night splinting helps patients with sleeping. There is no evidence that wrist splinting is disease modifying. The importance of wrist braces and splints in the CTS is known, but many people are unwilling to use braces. 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 day time activity primarily causing stress on the wrists.
- Localized steroid injections: Steroid injections can be quite effective for temporary relief from symptoms of CTS for a short time frame while a patient develops a long term strategy that fits with his/her lifestyle. In certain patients, an injection may also be of diagnostic value. This treatment is not appropriate for extended periods, however. In general, medical professionals only prescribe to localized steroid injections until the treatment options can be identified. For most patients, permanent relief requires surgery.
- Physiotherapy: There is little evidence to support physiotherapy or occupational therapy as disease modifying treatments.
- Occupational therapy: The comments provided in this section appear more suited to nonspecific activity related arm pains that to true carpal tunnel syndrome. Occupational therapy offers ergonomic suggestions to prevent worsening of the symptoms and occupational therapist facilitates hand functions through functional activities and helps to regain the functions which are necessary for the functional living through remedial adaptive approaches.
- Medication: using an over-the-counter anti-inflammatory such as aspirin, ibuprofen or naproxen can be effective as well as for controlling symptoms. Pain relievers like paracetamol will only mask the pain, and only an anti-inflammatory medications theoretically can treat the root swelling and thus the source of the problem. Oral steroids do the same, but are generally not used for this purpose because of significant side effects. Use of non-steroidal anti-inflammatory drugs may worsen asthma symptoms in some with a history of asthma, making the use of steroids such as prednisone the safer option for treating CTS. The most common complications associated with long-term use of anti-inflammatory medications have been linked to heart complications. Use of anti-inflammatory medication for chronic, long-term pain should be done under doctor supervision. A more aggressive pharmaceutical option is an injection of cortisone, to reduce swelling and nerve pressure within the carpel tunnel.
- Carpal tunnel release surgery: Release of the transverse carpal ligament (“carpal tunnel release”) surgery is recommended when there is static (ever-present, not just intermittent numbness), weakness of palmar abduction, 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.
Make sure you consult a doctor after the surgery if you experience fever, redness, swelling or tenderness.