High-definition point-of-care ultrasound in neurogenic thoracic outlet syndrome: An evidence-informed clinical perspective.

Abstract

Neurogenic thoracic outlet syndrome (nTOS) remains diagnostically challenging because symptoms are common, objective neurological signs are often absent, and conventional investigations may be normal or non-specific. Contemporary diagnostic frameworks remain predominantly clinical, leaving clinicians to infer the anatomical site and mechanism of compression before committing patients to injection, rehabilitation, or decompressive surgery. This opinion article argues that high-frequency point-of-care ultrasound (HF-POCUS) should be incorporated into specialist nTOS assessment as an adjunct to, not a replacement for, clinical diagnosis. HF ultrasound can directly visualise the supraclavicular brachial plexus, lower trunk deformation, fibromuscular bands, cervical rib variants, scalene anomalies, and dynamic vascular compromise that may mark costoclavicular narrowing. Evidence suggests that nerve ultrasound alone has limited sensitivity but useful specificity, while combining targeted brachial plexus neurosonography with dynamic duplex assessment substantially improves diagnostic yield and anatomical localisation. The technique is particularly valuable when it identifies surgically relevant findings such as the wedge-sickle sign, focal lower trunk distortion, distal oedematous thickening, or reproducible symptom provocation during scanning. However, HF-POCUS is operator dependent and vulnerable to over-interpretation, especially where dynamic vascular compression is present in asymptomatic individuals. Safe implementation therefore requires defined training, stored images, structured reporting, quality assurance, and explicit integration with clinical criteria, electrodiagnostic testing, MRI, and response to scalene injection where appropriate. Used within this governed framework, HF-POCUS has the potential to reduce diagnostic ambiguity, shorten time to decision-making, improve surgical planning, support more transparent patient counselling, and create a reproducible pre-operative anatomical hypothesis for clinical decision-making processes in suspected nTOS.