Thoracic outlet syndromes.

The term thoracic outlet syndromes, is a group designation for several distinct disorders (one of questionable validity) involving various components of the brachial plexus, the blood vessels, or both, at various points between the base of the neck and the axilla. Four of the five subgroups (true neurologic TOS, arterial vascular TOS, venous vascular TOS, and traumatic neurovascular TOS) are universally recognized to be rare lesions, with characteristic clinical and laboratory presentations; and none is particularly controversial. In contrast, disputed neurologic TOS is highly controversial. This article limits discussion to the three subgroups of TOS in which neurologic symptoms are caused, or reputedly are caused, by compromise of the brachial plexus fibers.