Signs and symptoms
TOS affects mainly the upper limbs, with signs and symptoms manifesting in the shoulders, neck, arms and hands. Pain can be present on an intermittent or permanent basis. It can be sharp/stabbing, burning, or aching. TOS can involve only part of the hand (as in the pinky and adjacent half of the ring finger), all of the hand, or the inner aspect of the forearm and upper arm. Pain can also be in the side of the neck, the pectoral area below the clavicle, the armpit/axillary area, and the upper back (i.e., the trapezius and rhomboid area). Discoloration of the hands, one hand colder than the other hand, weakness of the hand and arm muscles, and tingling are commonly present.Only 1% of people with carpal tunnel syndrome have concomitant TOS.Repetitive motions can cause enlargement of muscles which causes compression of veins. Besides, overuse injury of the upper limbs causes swellings, small bleeding, and subsequent fibrosis which would cause the thrombosis of the subclavian vein, leading to Paget–Schroetter disease or effort-induced thrombosis.TOS can be related to cerebrovascular arterial insufficiency when affecting the subclavian artery. It also can affect the vertebral artery, in which case it could produce vision disturbances, including transient blindness, and embolic cerebral infarction.TOS can also lead to eye problems and vision loss as a circumstance of vertebral artery compression. Although very rare, if compression of the brain stem is also involved in an individual presentation of TOS, transient blindness may occur while the head is held in certain positions.
Thoracic outlet syndrome (TOS) is a condition in which there is compression of the nerves, arteries, or veins in the passageway from the lower neck to the armpit. There are three main types: neurogenic, venous, and arterial. The neurogenic type is the most common and presents with pain, weakness, paraesthesia, and occasionally loss of muscle at the base of the thumb. The venous type results in swelling, pain, and possibly a bluish coloration of the arm. The arterial type results in pain, coldness, and pallor of the arm.TOS may result from trauma, repetitive arm movements, tumors, pregnancy, or anatomical variations such as a cervical rib. The diagnosis may be supported by nerve conduction studies and medical imaging. TOS is difficult to diagnose and there are many potential differential diagnoses as well as other diseases that are often co-occurrent with TOS.Initial treatment for the neurogenic type is with exercises to strengthen the chest muscles and improve posture. NSAIDs such as naproxen may be used for pain. Surgery is typically done for the arterial and venous types and for the neurogenic type if it does not improve with other treatments. Blood thinners may be used to treat or prevent blood clots. The condition affects about 1% of the population. It is more common in women than men and it occurs most commonly between 20 and 50 years of age. The condition was first described in 1818 and the current term "thoracic outlet syndrome" first used in 1956.