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A condition associated with compression of the BRACHIAL PLEXUS; SUBCLAVIAN ARTERY; and SUBCLAVIAN VEIN at the thoracic outlet and caused by a complete or incomplete anomalous cervical rib or fascial band connecting the tip of a cervical rib with the first thoracic rib. Clinical manifestations may include pain in the neck and shoulder which radiates into the upper extremity, PARESIS or PARALYSIS of brachial plexus innervated muscles; sensory loss; PARESTHESIAS; ISCHEMIA; and EDEMA. (Adams et al., Principles of Neurology, 6th ed, p214)