Thoracic outlet syndrome (TOS) is one of the most controversial diagnoses in medicine. It is a spectrum of disorders that includes three related syndromes: a form where the brachial plexus, a collection of nerves in the neck and armpit, is compressed (the neurogenic form); a vascular form involving compression of the subclavian artery or vein, which are major blood vessels of the upper chest; and non-specific or disputed TOS. Clinical features may include pain in the shoulder and neck which spreads into the arm; weakness; decreased sensation; swelling; and a restricted blood supply to the affected arm.
TOS may result from a variety of abnormalities such as an extra rib in the neck (cervical rib syndrome), differences in the shape of the vertebrae, abnormal bands of tissue beneath the skin (fascial bands), and abnormalities of how muscles in the side of the neck attach to the bones. TOS is often associated with a history of trauma. There is a lack of widely accepted standards for making the diagnosis, so that for the purpose of this review we did not use objective criteria but relied exclusively on the diagnosis of TOS in participants by the investigators in the reviewed studies. The diagnosis of TOS is often made after other conditions that can cause one-sided symptoms of arm pain, weakness or sensory loss, or all three, have been excluded. Most people diagnosed with TOS have the disputed form.
This study demonstrated that there is not currently enough evidence that the established interventions for thoracic outlet syndrome are helpful in relieving pain. Until high quality, randomized clinical trials comparing the various interventions for TOS are performed, the decision whether to treat and the appropriate choice of treatment will have to be based on the preferences of the individual and health care provider.