2026 Workshop Handout Bundle-W83RD - Basic Nerve US - Upper Limb

W83RD - Basic Nerve US - Upper Limb - Sultan

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This workshop reviews the history, principles, and clinical uses of ultrasound in neuromuscular medicine. Key milestones include early investigations of sound and echolocation, the discovery of piezoelectricity, development of the first transducer, and the introduction of ultrasound for medical diagnosis and obstetric imaging. Peripheral nerve ultrasound was described in 1988, with early studies assessing its usefulness in diagnosing carpal tunnel syndrome.<br /><br />Ultrasound can show nerves in cross-sectional and longitudinal views. Entrapment neuropathy assessment considers nerve cross-sectional area, echotexture, shape, fascicle size, vascularity, and mobility. Enlargement may be defined by comparison with reference values or an unaffected portion of the same nerve. The workshop covers carpal tunnel syndrome (CTS), ulnar neuropathy at the elbow and wrist, and fibular neuropathy at the knee. Approximate cross-sectional area thresholds include 10–12 mm² for the median nerve in CTS, 9–10 mm² for the ulnar nerve near the elbow, 8 mm² for the ulnar nerve at the wrist, and 20 mm² for the fibular nerve at the knee. Ultrasound can also identify structural causes, including ganglion cysts.<br /><br />Normal muscle generally appears relatively dark, with a characteristic speckled pattern in cross-section and linear or pennate features longitudinally. Echogenicity tends to increase with age and may rise with muscle disease. The Heckmatt scale grades muscle appearance from normal to markedly increased echogenicity with loss of the bone echo. Ultrasound can measure muscle thickness and cross-sectional area, but reliable measurement depends on consistent positioning, minimal probe pressure, and standardized landmarks.<br /><br />Muscle ultrasound may reveal atrophy, hypertrophy, fatty or fibrotic change, abnormal fascia, fasciculations, tears, hematomas, and tumors. These findings can help identify an appropriate muscle for biopsy.

Keywords

ultrasound

nmus

sono

neuromuscular medicine

peripheral nerve ultrasound

carpal tunnel syndrome

CTS

ulnar neuropathy

fibular neuropathy

cross-sectional area

muscle echogenicity

Heckmatt scale

muscle biopsy