Dynamic Neuromusculoskeletal Ultrasound Documentation of Brachial Plexus/Thoracic Outlet Compression during Elevated Arm Stress Testing

Abstract

Background The diagnosis and validation of thoracic outlet syndrome/brachial plexopathy (TOS) remains a difficult challenge for surgeons, neurologists, and radiologists. This is due to the fact that the responses of standard elevated arm stress tests can be considered somewhat subjective and can vary. Therefore, non-vascular TOS cases are presently diagnosed clinically, and any objective diagnosis has been controversial. Methods This is a technique paper describing the use of dynamic neuromusculoskeletal ultrasound to assist in the diagnosis of thoracic outlet/brachial plexus pathology. We propose a new way to observe the brachial plexus dynamically, so that physical verification of nerve compression between the anterior and middle scalene muscles can be clearly made at the onset of clinical symptoms. This gives a way to objectively identify clinically significant brachial plexus compression. Results Dynamic testing can add objective analysis to tests such as the elevated arm stress tests and can correlate the onset of symptoms with plexus compression between the anterior and middle scalene muscles. With this, the area of pathologic compression can be identified and viewed while performing the dynamic testing. If compression is seen and the onset of symptoms ensues, this is a positive confirmatory test for the presence of TOS and a clinically significant disease. Conclusions This paper offers a simple, objective, and visual diagnostic test that can validate the presence or absence of brachial plexus compression during arm elevation in patients with brachial plexus injury and thoracic outlet syndrome.

The diagnosis of thoracic outlet syndrome

“…Dynamic assessment of the brachial plexus at the level of the interscalene hiatus using ultrasound while performing clinical tests can demonstrate compression between anterior and middle scalene muscles. 43 Simultaneous provocation of symptoms with this ultrasonographic appearance can confirm the diagnosis of compression of the brachial plexus.…”

Diagnosing Thoracic Outlet Syndrome: Current Approaches and Future Directions

“…In this technique, when an ultrasound probe is placed in the supraclavicular fossa, the brachial plexus can be visualised generally above and just posterior to the subclavian artery, and can be seen in relation to the surrounding anterior and middle scalene muscles. When the patient is asked to abduct the arm in performance of the EAST, reduction in the interscalene interval, compression of the brachial plexus, or obliteration of the visualised nerves can be correlated with the reproduction of symptoms to add weight to a diagnosis of NTOS [ 48 ]. This technique, however, requires more rigorous evaluation.…”

Ultrasound-Guided Hydroneurolysis of the Median Nerve for Recurrent Carpal Tunnel Syndrome

“…US data have clearly demonstrated the ability to visualize compression of peripheral nerves from the brachial plexus to the carpal tunnel. 2,7,[10][11][12]14,15,19,23,[26][27][28]41,42 Any individual who is skilled in US evaluation is aware that the median nerve is not a static structure within the carpal canal. 21 The flexor tendons are dynamic and move through the canal.…”