Thoracic Outlet Syndrome in Emergency Medicine Clinical Presentation

Updated: Aug 25, 2020
  • Author: Andrew K Chang, MD, MS; Chief Editor: Erik D Schraga, MD  more...
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Neurologic symptoms occur in 95% of cases of thoracic outlet syndrome (TOS). The lower two nerve roots of the brachial plexus, C8 and T1, are most commonly (90%) involved, producing pain and paresthesia in the ulnar nerve distribution.

The second most common anatomic pattern involves the upper three nerve roots of the brachial plexus, C5, C6, and C7, with symptoms referred to the neck, ear, upper chest, upper back, and outer arm in the radial nerve distribution.

Neurologic TOS (NTOS)

Most patients have a history of neck trauma preceding their symptoms, most commonly from auto accidents and repetitive stress at work. Symptoms of neurologic TOS (NTOS) are most often those of nerve irritation and include the following:

  • Pain, particularly in the medial aspect of the arm, forearm, and the ring and small digits

  • Paresthesia, often nocturnal, awakening the patient with pain or numbness. Most often involves all five fingers but usually is most noticeable in the fourth and fifth fingers and the ulnar forearm.

  • Weakness

  • Cold intolerance

  • Neck pain, pain over the trapezium, anterior chest wall pain, and occipital headache may also occur.

  • Raynaud phenomenon, hand coldness, and color changes may also be seen, usually due to an overactive sympathetic nervous system as opposed to ischemia.

Venous TOS

Venous TOS (VTOS) is most often seen in younger men and presents with pain, often preceded by excessive activity in the arms. Symptoms of VTOS are those of an obstructed vein and include the following:

  • Swelling of the arm

  • Paresthesias in the fingers and hand (may be secondary to swelling as opposed to nerve compression)

Arterial TOS

Arterial TOS (ATOS) is often in young adults with a history of vigorous arm activity. Symptoms are those of digital and hand ischemia, and usually develop spontaneously from arterial emboli. Symptoms of ATOS include the following:

  • Pain

  • Pallor

  • Coldness

  • Paresthesias


Physical Examination

In most cases, the physical examination findings of thoracic outlet syndrome (TOS) are completely normal. Other times, the examination is difficult because the patient may guard the extremity and exhibit giveaway-type weakness. The sensory examination is often unreliable.

Provocative testing

Provocative tests, such as the Adson, costoclavicular, and hyperabduction maneuvers, are unreliable. Approximately 92% of asymptomatic patients have variation in the strength of the radial pulse during positional changes.

Elevated arm stress test

The elevated arm stress test (EAST) is of debatable use, but it may be the most reliable screening test. It evaluates all three types of TOS.

To perform this test, the patient sits with the arms abducted 90 degrees from the thorax and the elbows flexed 90 degrees. The patient then opens and closes the hands for 3 minutes.

Patients with TOS cannot continue this for 3 minutes because of reproduction of symptoms. Patients with carpal tunnel syndrome experience dysesthesia in the fingers, but do not have shoulder or arm pain.

Upper limb tension test of Elvey

The upper limb tension test of Elvey may be helpful. This test serially puts tension on the brachial plexus similar to straight leg raising in the lower extremity.

Neurologic evaluation

Findings in the neurologic evaluation include the following:

  • A typical patient is a young, thin female with a long neck and drooping shoulders.

  • A positive EAST test result and the presence of a radial pulse are strong indicators of neurologic involvement of the brachial plexus.

  • Supraclavicular tenderness may be present.

  • Usually, no evidence of muscle atrophy is present, although the classic finding is known as the Gilliatt-Sumner hand, with the most dramatic atrophy in the abductor pollicis brevis, with lesser involvement of the interossei and hypothenar muscles.

  • Paresthesia/sensory loss is restricted to the ulnar aspect of the hand and forearm.

  • Weakness (usually subtle) of the affected limb may be noted.

Venous evaluation

Findings in the venous evaluation include the following:

  • Edema of the upper extremity

  • Cyanosis of the upper extremity

  • Distended superficial veins of the shoulder and chest

Arterial evaluation

Findings in the arterial evaluation include the following:

  • Pallor and pulselessness

  • Coolness of the affected upper extremity

  • Lower blood pressure in affected arm of greater than 20 mm Hg (a reliable indicator of arterial involvement)

  • Multiple small infarcts on the hand and fingers (embolization) (rarely)