Introduction
Why do you need an imaging test for thoracic outlet syndrome (TOS) to assess soft tissues and rule out differential diagnoses like spinal cord issues? Curious about how this diagnostic tool can provide crucial insights into your health? Imaging tests play a vital role in identifying TOS, guiding treatment decisions, and ensuring accurate diagnosis of soft tissues for doctors and differential diagnoses.
Table of Contents
Table of Contents
Adson’s sign: Patient extends neck + turn head to side being tested ➔ hold breath ➔ if radial pulse gone ➔ thoracic outlet syndrome present
Adson's sign: Patient extends neck + turn head to side being tested ➔ hold breath ➔ if radial pulse gone ➔ thoracic outlet syndrome present
— LearntheHeart.com (@LearntheHeart) December 21, 2018
Unfortunately, this simply isn’t correct.
Alfred Adson was a pioneering neurosurgeon at the Mayo Clinic in the early 20th century. He surgically treated patients with cervical ribs and arterial TOS. Adson reasoned that the cervical rib was compressing the subclavian artery because the artery was in a confined space (the scalene triangle). Adson relieved this compression NOT by removing the cervical rib, but by releasing the anterior scalene muscle. This procedure is called a scalenotomy. This scalenotomy freed up the anterior boundary of the scalene triangle, while the cervical rib remained the posterior boundary. Thus, the subclavian artery could slide forward, relieving compression.
The procedure was much easier than removing cervical rib. However, a significant amount of patients did have recurrent scarring or reattachment of the anterior scalene to the rib, causing recurrence of their symptoms. The procedure eventually fell out of favor.
Adson developed the test named after him. Indeed, in some cases, a positive Adson’s test can indicate compression of the artery in the scalene triangle. However, compression of the subclavian artery is not the same thing as arterial TOS. Arterial TOS is present when patients have symptoms caused by arterial blood clot, emboli, ischemia (lack of oxygen in blood to the arm), or aneurysm of the subclavian artery. The clinical presentation is usually dramatic and unmistakeable. We have many diagnostic tests to show the pathology. Adson did not have such tests, so he can be forgiven for doing the best he could with the tools he had. But today the Adson test is of little value.
One more thing-the Adson test has very low accuracy in diagnosing neurogenic TOS. The test has significant false positive and false negative results for neurogenic TOS. And neurogenic TOS is by far the most common form of TOS. It is also the most difficult to diagnose. Adson’s test does not significantly help with the diagnosis, and it does not show us the underlying pathology. We have far better diagnostic tests for TOS than Adson ever had. Since the year is 2019, we should use them.
