Thoracic outlet syndrome
Template:DiseaseDisorder infobox
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Overview
Thoracic outlet syndrome (TOS) consists of a group of distinct disorders that affect the nerves in the brachial plexus (nerves that pass into the arms from the neck) and various nerves and blood vessels between the base of the neck and axilla (armpit).
Epidemiology
TOS is more common in women. The onset of symptoms usually occurs between 20 and 50 years of age.
Causes
For the most part, these disorders are produced by positional compression of the subclavian artery and vein, the vertebral artery, and the nerve cords of the brachial plexus.
TOS may also result from a cervical band, abnormalities of the scalene muscles (including hypertrophy) and trauma.
Classification
Old Classification
The following taxonomy of TOS is used in ICD-9-CM and other sources:
- Scalenus anticus syndrome (compression on brachial plexus and/or subclavian artery caused by muscle growth) - diagnosed by using Adson's sign with patient's head turned outward
- Cervical rib syndrome (compression on brachial plexus and/or subclavian artery caused by bone growth) - diagnosed by using Adson's sign with patient's head turned inward
- Costoclavicular syndrome (narrowing between the clavicle and the first rib) -- diagnosed with costoclavicular maneuver[1]
New Classification
- Neurogenic TOS has a characteristic sign, called the Gilliatt-Sumner hand, in which there is severe wasting in the fleshy base of the thumb. There may be numbness along the underside of the hand and forearm, or dull aching pain in the neck, shoulder, and armpit.
- Vascular TOS features pallor, a weak or absent pulse in the affected arm, which also may be cool to the touch and appear paler than the unaffected arm. Symptoms may include numbness, tingling, aching, and heaviness.
- Non-specific TOS most prominently features a dull, aching pain in the neck, shoulder, and armpit that gets worse with activity. Non-specific TOS is frequently triggered by a traumatic event such as a car accident or a work related injury. It also occurs in athletes, including weight lifters, swimmers, tennis players, and baseball pitchers.
Diagnosis
Nerve conduction studies, electromyography, or imaging studies are recommended to confirm or rule out a diagnosis of TOS.
Adson's sign and the costoclavicular maneuver are notoriously inaccurate, and may be a small part of a comprehensive history and physical examination of a patient with TOS. There is currently no single clinical sign that makes the diagnosis of TOS with certainty. Arteriography, while only rarely used to evaluate thoracic outlet syndrome, may be used if a surgery is being planned to correct an arterial TOS.[2]
Treatment
Often, continued and active postural changes along with physiotherapy, massage therapy, chiropractic or osteopathic manipulation, will suffice. The recovery process however is long term, and a few days of poor posture can often set one back.
About 10 to 15% of patients undergo surgical decompression following an appropriate trial of conservative therapy, most often specific physical therapy directed towards the treatment of thoracic outlet syndrome, and usually lasting between 6 and 12 months. Surgical treatment may include removal of anomalous muscles, removal of the native anterior and/or middle scalene muscles, removal of the first rib or, if present, a cervical rib, or neurolysis (removal of fibrous tissue from the brachial plexus).
Noninvasive
- Stretching
The goal of self stretching is to relieve compression in the thoracic cavity, reduce blood vessel and nerve impingement, and realign the bones, muscles, ligaments, and tendons causing the problem.- Moving shoulders forward (hunching) then back to neutral, followed by extending them back (arching) then back to neutral, followed by lifting shoulders then back to neutral.
- Tilting and extending neck opposite to the side of injury while keeping the injured arm down or wrapped around the back.
- Nerve Gliding
This syndrome causes a compression of a large cluster of nerves, resulting in the impairment of nerves throughout the arm. By performing nerve gliding exercises one can stretch and mobilize the nerve fibers. Chronic and intermittent nerve compression has been studied in animal models, and has a well-described pathophysiology, as described by Susan Mackinnon, MD, currently at Washington University in St. Louis. Nerve gliding exercises have been studied by several authorities, including David Butler in Australia.- Extend your injured arm with fingers directly outwards to the side. Tilt your head to the otherside, and/or turn your head to the other side. A gentle pulling feeling is generally felt throughout the injured side. Initially, only do this and repeat. Once this exercise has been mastered and no extreme pain is felt, begin stretching your fingers back. Repeat with different variations, tilting your hand up, backwards, or downwards.
- Posture
TOS is rapidly aggravated by poor posture. Active breathing exercises and ergonomic desk setup can both help maintain active posture. Often the muscles in the back become weak due to prolonged (years) hunching. - Ice/Heat
Ice can be used to decrease inflammation of sore or injured muscles. Heat can also aid in relieving sore muscles by improving circulation to them. While the whole arm generally feels painful, some relief can be seen when ice/heat is applied to the thoracic region (collar bone, armpit, or shoulder blades).
Invasive
- Cortisone
Injected into a joint or muscle, cortisone can help relief and lower inflammation. - Botox injections
Short for Botulinum Toxin A, Botox binds nerve endings and prevents the release of neurotransmitters that activate muscles. A small amount of Botox injected into the tight or spastic muscles found in TOS sufferers often provides months of relief while the muscles is temporarily paralyzed. This noncosmetic treatment is unfortunately not covered by most medical plans and costs upwards of $400. Botox is VERY long-lasting, and its use will probably be based on results of ongoing research. Serious side effects have been reported, and are similarly long-lasting, so improved understanding of the mechanism of a 'scalene block' is vital to determining the benefit and risk of using Botox. - Surgical approaches have also been used.[3]
- Provocative test: The injection of a short-acting anesthetic such as xylocaine into the anterior scalene, subclavius, or pectoralis minor muscles as a provocative test to assist in the diagnosis of thoracic outlet syndrome. This is referred to as a 'scalene block'. If the patient experiences symptomatic relief for approximately 15 minutes following this procedure, surgical decompression is more likely to be successful in leading to the same level of symptomatic relief. However, this is not considered a 'treatment', as the relief is expected to wear off within an hour or two, at a maximum. Active research continues into the accuracy and risks of this provocative test.
Prognosis
The outcome for individuals with TOS varies according to type. The majority of individuals with TOS will improve with exercise and physical therapy. Vascular TOS, and true neurogenic TOS often require surgery to relieve pressure on the affected vessel or nerve.
References
- ↑ Template:FPnotebook
- ↑ Thoracic outlet syndrome Mount Sinai Hospital, New York
- ↑ Rochkind S, Shemesh M, Patish H; et al. (2007). "Thoracic outlet syndrome: a multidisciplinary problem with a perspective for microsurgical management without rib resection". Acta Neurochir. Suppl. 100: 145–7. PMID 17985565.
External links
- Template:NINDS
- American Thoracic Outlet Syndrome Association [3]
- Tos-Syndrome.com
- Journal of American Chiropractic Association
- Adson's test [4]
- Physical Therapy Corner - Thoracic Outlet Syndrome
- Society for Vascular Surgery (U.S.)
- Division of Vascular Surgery and Endovascular Therapy at the Baylor College of Medicine
Template:SIB Template:PNS diseases of the nervous system
nl:Thoracic outlet syndrome fi:Hartiapunoksen vammautuminen tai ahtautuminen