Highlights
- •Contrary to the traditional view, TN-TOS patients often present with sensory symptoms.
- •The decrease of SNAP amplitude of MABC nerve in NCS seems the most sensitive marker.
- •MRI and CTA findings could be used as an ancillary data for the diagnosis of TN-TOS.
Abstract
Objective
True neurogenic thoracic outlet syndrome (TN-TOS) is an extremely rare neuromuscular
disease. We report clinical, electrodiagnostic and radiologic features of patients
with TN-TOS.
Methods
Retrospective chart review of patients satisfying criteria was done. Nerve conduction
study (NCS) and needle electromyography (EMG) of upper extremity were reviewed. Brachial
plexus MRI and computed tomography angiography (CTA) were also reviewed.
Results
Thirteen TN-TOS patients were identified. The most common neurologic signs were hypesthesia
in the medial forearm or ulnar digits and weakness of the abductor pollicis brevis
(APB) muscle. In NCS, medial antebrachial cutaneous (MABC) sensory nerve action potential
amplitude was decreased in all tested patients. The APB muscle was most commonly involved
in EMG. Among radiologic criteria, focal stenosis of subclavian artery in CTA was
the most common finding.
Conclusion
We confirmed that TN-TOS is T1 predominant lower roots/trunk brachial plexopathy with
clinical and electrodiagnostic features. Radiologic studies may be used to detect
structural abnormalities.
Significance
As MABC NCS showed abnormal results in all tested patients, it should be added to
electrodiagnostic study as screening method. If present, structural abnormalities
might be confirmed with radiologic studies.
Keywords
Abbreviations:
ADM (abductor digiti minimi), APB (abductor pollicis brevis), CMAP (compound muscle action potential), CTA (computed tomography angiography), EIP (extensor indicis proprius), EMG (electromyography), FDI (first dorsal interossei), MRI (magnetic resonance imaging), MABC (medial antebrachial cutaneous), NCS (nerve conduction study), SCA (subclavian artery), SNAP (sensory nerve action potential), STIR (short tau inversion recovery), TN-TOS (true neurogenic thoracic outlet syndrome), TOS (thoracic outlet syndrome)To read this article in full you will need to make a payment
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Article info
Publication history
Published online: July 19, 2019
Accepted:
July 18,
2019
Received in revised form:
July 16,
2019
Received:
April 25,
2019
Footnotes
☆We confirm that we have read the Journal's position on issues involved in ethical publication and affirm that this report is consistent with those guidelines. None of the authors has any conflict of interest to disclose. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
Identification
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© 2019 Elsevier B.V. All rights reserved.
