2025 Workshop Handout Bundle-W98B Most out of US system- Sultan

W98B Most out of US system- Sultan

Pdf Summary

Neuromuscular ultrasound (NMUS) is an increasingly vital tool in diagnosing and managing peripheral nerve and muscle disorders. It complements electrodiagnostic studies by providing real-time, structural, and dynamic imaging that enhances clinical assessment, particularly in entrapment neuropathies such as carpal tunnel syndrome, ulnar neuropathy at the elbow, ulnar neuropathy at the wrist, and fibular neuropathy at the knee.<br /><br />Ultrasound transducers typically are high-frequency linear arrays (12–18 MHz) used to image superficial nerves and muscles. Higher frequencies yield better resolution but less penetration, while lower frequencies are used for deeper structures. Gel application is essential to optimize ultrasound coupling, and proper transducer handling—held between thumb and fingers with minimal pressure—is critical for image quality.<br /><br />Nerves appear as honeycomb structures in cross-section, with hyperechoic epineurium surrounding hypoechoic fascicles. Key measurements include cross-sectional area (CSA), obtained by tracing within the epineurium on a perpendicular view. In entrapment neuropathies, nerves typically show focal fusiform enlargement proximal to compression sites, often hypoechoic with altered mobility and increased intraneural vascularity. CSA enlargement thresholds vary; for example, a median nerve CSA >10 mm² at the wrist suggests carpal tunnel syndrome. Ratios comparing site of maximal enlargement to adjacent unaffected nerve segments improve diagnostic accuracy.<br /><br />Muscle ultrasound reveals characteristic striated architecture; pathology often manifests as increased echogenicity (brightness) due to fatty infiltration and fibrosis and muscle atrophy, reducing thickness. Accurate muscle thickness measurement requires minimal probe pressure and consistent imaging sites. Fasciculations are visible as focal movements and can guide electromyography.<br /><br />NMUS also aids in traumatic neuropathies by detecting nerve transection and neuromas, and in generalized neuropathies by visualizing diffuse nerve enlargement. Additionally, ultrasound guides injections, biopsies, and regional anesthesia, improving safety and precision.<br /><br />In summary, neuromuscular ultrasound is a safe, accessible, and informative extension of clinical and electrodiagnostic examinations. Mastery requires practice in technique and interpretation but offers valuable insights for focal neuropathies and broader neuromuscular disorders. Its use is expanding beyond entrapment syndromes into inflammatory, inherited, and motor neuron diseases, promising improved diagnosis, prognostication, and therapeutic guidance.

Keywords

neuromuscular ultrasound

peripheral nerve disorders

entrapment neuropathies

carpal tunnel syndrome

CTS

ultrasound transducers

cross-sectional area

muscle echogenicity

nerve enlargement

electrodiagnostic studies

regional anesthesia guidance