Thoracic outlet syndrome

A condition due to compromise of blood vessels or nerve fibers between the armpit (axilla) and base of the neck, usually due to compression of nerves or blood vessels between the neck and shoulders. Symptoms include pain, arm weakness, and numbness in the hands and fingers. Thoracic outlet syndrome can be caused by overstress from some types of manual work or exercise, injury, malformation, and less commonly by tumors of the top of the lung. Treatment is by physical therapy and antiinflammatory medication, and

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see scalenus syndrome

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any of a variety of neurovascular syndromes resulting from compression of the subclavian artery, the brachial plexus nerve trunks, or less often the axillary vein or subclavian vein, by thoracic outlet abnormalities such as a drooping shoulder girdle, a cervical rib or fibrous band, an abnormal first rib, or occasionally compression of the edge of the scalenus anterior muscle. Continual hyperabduction of the arm may cause another variety (hyperabduction s.). Arterial compression leads to ischemia, paresthesias, numbness, and weakness of the affected arm, sometimes with Raynaud phenomenon of the arm. Nerve compression causes atrophy and weakness of the muscles of the hand and, in advanced cases, of the forearm, with pain and sensory disturbances in the arm. Venous obstruction usually takes the form of the Paget-Schroetter syndrome. Other types include cervical rib s., costoclavicular s., and scalenus anticus s.