neurologic disorders
Thoracic Outlet Compression Syndromes (TOS)
Introduction
Thoracic outlet compression syndromes are a group of poorly defined disorders characterized by pain and paresthesias in a hand, the neck, a shoulder, or an arm. They appear to involve compression of the brachial plexus (and perhaps the subclavian vessels) as these structures traverse the thoracic outlet. Diagnostic techniques have not been established. Treatment includes physical therapy, analgesics, and, in severe cases, surgery. Pathogenesis is often unknown but sometimes involves compression of the lower trunk of the brachial plexus (and perhaps the subclavian vessels) as these structures traverse the thoracic outlet below the scalene muscles and over the 1st rib, before they enter the axilla, but this involvement is unclear. Compression may be caused by A cervical rib An abnormal 1st thoracic rib Abnormal insertion or position of the scalene muscles A malunited clavicle fracture Thoracic outlet syndromes are more common among women and usually develop between age 35 and 55. 