Thoracic outlet syndrome

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 the subclavian artery and vein blood vessels between the base of the neck and axilla (armpit).

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Causes

For the most part, these disorders are produced by compression of the components of the brachial plexus (the large cluster of nerves that pass from the neck to the arm), the subclavian artery, or the subclavian vein. These subtypes are referred to as neurogenic TOS, arterial TOS, and venous TOS, respectively. The compression may be positional (caused by movement of the clavicle and shoulder girdle on arm movement) or static (caused by abnormalities or enlargement of the various muscles surrounding the arteries, veins and brachial plexus).

The neurogenic form of TOS accounts for 95 to 98% of all cases of TOS.

It is known from pathological studies of cadavers, and from surgical studies of patients with TOS, that there are numerous anomalies of the scalene muscles and the other muscles that surround the arteries, veins and brachial plexus. TOS may result from these anomalies of the scalene muscles or from enlargement (hypertrophy) of the scalene muscles. One common cause of hypertrophy is trauma, as may occur in motor vehicle accidents.

The two groups of people most likely to develop TOS are those suffering neck injuries in motor vehicle accidents and those who use computers in non-ergonomic positions for extended periods of time, especially for their occupation.

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]

Treatment

Only a few patients require surgical decompression through either removal of the upper rib, muscle scraping, or scar tissue. Often, continued and active postural changes along with physiotherapy or osteopathy will suffice. The recovery process however is long term, and a few days of poor posture can often set one back.

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
  Often, due to poor circulation and mobility, the nerves throughout the arm become weak and immobile. By performing nerve gliding exercises one can stretch and mobilize the nerve fibers.
  • 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. It is important to note that while the whole arm generally feels painful, major relief can be seen when ice/heat is applied to the thoracic region. (Placed on collar bone, armpit, or shoulder blades.)

Invasive

• Cortisone
  Injected into a joint, muscle, or tendon, 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.

Surgical approaches have also been proposed.^[2]

Notable patients

Major League Baseball players Hank Blalock and Kenny Rogers have recently been diagnosed with Thoracic outlet syndrome. Kenny Rogers was diagnosed several years earlier with TOS in the other upper extremity. All-Star pitcher J. R. Richards suffered a career-ending stroke from an undiagnosed case of TOS. Pitcher David Cone had a variant case of TOS, with an arterial aneurysm of the upper aspect of his pitching arm.

Overhead athletes, such as swimmers and volleyball players, are known to be predisposed to the development of TOS.

Musician Isaac Hanson suffered a potentially life threatening pulmonary embolism as a complication to thoracic outlet syndrome.^[3]

References

1. ^ ORT63 at FPnotebook
2. ^ 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.
3. ^ People Magazine. Retrieved on 2008-01-01.