Neuromuscular ultrasound is becoming an increasingly important diagnostic tool in the assessment of brachial plexopathies. Tawfik et al. provide a practical review of brachial plexus ultrasound, covering applied anatomy, scanning technique, and evidence-based indications. Although electrodiagnostic studies remain essential for determining lesion severity, ultrasound adds a structural assessment and can be performed at the bedside. MRI remains superior for preganglionic lesions, but ultrasound allows high-resolution visualization of almost the entire postganglionic brachial plexus.
The authors emphasize that brachial plexus ultrasound requires detailed knowledge of sonoanatomy. A systematic scanning protocol includes supraclavicular, infraclavicular and axillary acoustic windows. The main ultrasound parameters are nerve size, echotexture and vascularity. Importantly, nerve enlargement is not disease-specific and must always be interpreted in the clinical and neurophysiological context.
Evidence-based indications include:
- traumatic brachial plexus injury (e.g. postganglionic structural lesions, preoperative mapping);
- neurogenic thoracic outlet syndrome (e.g. lower trunk compression and structural variants such as the wedge-sickle sign);
- Parsonage Turner syndrome (neuralgic amyotrophy, e.g. nerve swelling, hourglass constrictions or torsion).
Ultrasound may also support diagnosis in immune-mediated neuropathies, including CIDP, multifocal motor neuropathy and early Guillain-Barré syndrome, particularly when nerve conduction studies are borderline, incomplete or do not meet strict demyelination criteria. In suspected neoplastic plexopathy, ultrasound can detect masses along the plexus, although MRI and histopathology remain necessary for full evaluation.
The key message is that brachial plexus ultrasound should not replace clinical examination, electrodiagnostics or MRI, but rather be integrated with other diagnostic modalities to guide further clinical decisions.
Key Points:
- Brachial plexus ultrasound complements electrodiagnostic studies and MRI by adding high-resolution structural information at the bedside.
- Evidence-based indications include traumatic plexopathy, neurogenic thoracic outlet syndrome, neuralgic amyotrophy, CIDP/MMN and early Guillain-Barré syndrome.
- Sonographic abnormalities such as nerve enlargement are not disease-specific and should not be interpreted in isolation.
References:
Tawfik EA, Qerama E, Kerasnoudis A, van Alfen N. Neuromuscular ultrasound of the brachial plexus: know-how, know-when. Clinical Neurophysiology Practice. 2026. doi: 10.1016/j.cnp.2026.06.007.
Publish on behalf of the Scientific Panel on Clinical neurophysiology