Thoracic outlet syndrome:

• Thoracic outlet syndrome is a clinical constellation of symptoms secondary to neurovascular compression at the level of the thoracic outlet.
• These symptoms are often exacerbated by abduction of the arms. Patients may complain of worsened symptoms when their arms are raised.
• Neurologic symptoms can include pain, numbness, paresthesias, or weakness, usually in a radicular pattern. C8 and T1 are most commonly involved.
• Vascular symptoms can include pain, no pulse, and pallor.
• Physical examination maneuvers to elicit thoracic outlet syndrome include Adson's test and the elevated arm stress test (EAST).
• The Adson's test involves abducting the arm to 90 degrees, and having the patient take a deep breath and turning his/her head away from the affected arm. A positive Adson's test results in a decrease or absence of the affected arm's radial pulse.
• The EAST test involves abducting the upper arms to 90 degrees, and flexing the elbows to 90 degrees. The patient is then asked to open and close the hands vigorously. Affected patients will be unable to continue for three minutes as this arm positioning will elicit the clinical symptoms of thoracic outlet syndrome.
• Imaging studies include a chest radiograph to evaluate for thoracic bony abnormalities, such as cervical ribs. Upper extremity dopplers and angiography are used to confirm the diagnosis.
• Patients should be anticoagulated to an INR of 2-3 to minimize the chance of subclavian artery or vein thrombosis.
• Surgical treatment includes anterior and middle scalenectomy, first rib resection, and removal of a cervical rib if present.

References:

1. Emedicine. "Thoracic Outlet Syndrome" http://www.emedicine.com/emerg/topic578.htm