Thoracic Outlet Syndrome (Obstruction) Clinical Presentation

Updated: Sep 17, 2020
  • Author: Mark K Eskandari, MD; Chief Editor: Vincent Lopez Rowe, MD  more...
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History and Physical Examination

Neurogenic thoracic outlet syndrome

Neurogenic thoracic outlet syndrome (TOS) is a clinical diagnosis that only is made when objective findings are supported by subjective symptoms and physical findings. Other diagnoses that should be considered include tendinitisfibromyalgiacervical disc herniationspinal stenosiscarpal tunnel syndrome, repetitive motion syndrome, and epicondylitis.

A history of a motor vehicle collision (MVC) or other neck trauma is usually elicited, and patients may report a variety of symptoms, such as neck, shoulder, and arm pain. Symptoms of compression from all cords of the brachial plexus are the most common neurologic pattern noted with TOS.

It has often been maintained that ulnar nerve involvement is the typical pattern of symptoms related to neurogenic TOS, but this is not the case. Paresthesias and weakness in an arm, occipital headaches, and paraspinal muscle pain are common. The paraspinal muscle pain and occipital headaches are secondary to referred nerve pain.

As expected, specific symptoms coincide with the area of the brachial plexus that is compressed. On physical examination, symptoms usually can be reproduced with pressure on the scalenes and with abduction/external rotation (AER) of the arms. Coldness and color changes in the hand usually are secondary to sympathetic nerve involvement rather than arterial involvement.

The examination should focus on the neurologic and vascular findings. The scalene muscles and supraclavicular fossa should be carefully examined for abnormal pulsations, bruits, and pain with palpation. All upper-extremity pulses should be assessed, and provocative positioning should be performed during the vascular examination. Petechiae and other evidence of embolic events should also be sought.

Arterial thoracic outlet syndrome

The mean age of patients with arterial TOS at presentation is approximately 10 years older than that of patients with neurogenic TOS. Occasionally, arterial TOS is recognized during workup for other pathologies. An incidental pulsatile mass or a supraclavicular bruit may be noted during thorough physical examination. Unfortunately, arterial TOS usually remains unrecognized until a thromboembolic complication occurs. Patients who embolize may present with hand claudication, gangrene, and other embolic stigmata.

Venous thoracic outlet syndrome

In 80% of cases of venous TOS, the dominant extremity is involved. The diagnosis is based on the clinical presentation of upper-extremity swelling, venous engorgement, and pain. These signs and symptoms, in association with radiologic documentation of venous compression at the thoracic outlet, confirm the diagnosis of Paget-Schroetter syndrome. Sometimes, venous compression cannot be demonstrated, and the diagnosis is made clinically and by the pattern of venous thrombosis.

Pulmonary embolism has been reported in patients with primary venous thrombosis, but this more commonly occurs in patients presenting with secondary venous thrombosis. Secondary venous thrombosis occurs due to processes such as malignancy, polycythemia vera, heart failure, infection, drug abuse, thrombocytosis, estrogens, and, most commonly, central venous catheters and indwelling cardiac pacing wires.

Upper-extremity deep venous thrombosis (DVT) accounts for 1-4% of all DVTs, and primary venous thrombosis accounts for 25% of these cases. Catheter-related DVTs account for most upper-extremity DVTs.