Role of nerve ultrasound versus electrophysiological studies in the evaluation of nerve injuries

Abstract

Background: High-resolution ultrasonography (US) is a non-invasive, readily applicable imaging modality capable of depicting real-time static and dynamic information concerning the peripheral nerves and their surrounding tissues. Although electrophysiological studies are the gold standard in the evaluation of nerve injuries, US can be used also to evaluate the morphological changes of nerve injuries. Objectives: To evaluate the role of the high-resolution US in the assessment of nerve injuries and to compare it to the role of electrodiagnostic studies. Subjects and methods: A total of 30 nerves from 22 consecutive patients with clinically definite nerve injury were considered. Two independent and blinded clinicians perform electrodiagnosis and US. The clinical, neurophysiological, and US findings were collected, and the contribution of US was then classified as “ contributive” or “non-contributive”, according to whether US confirmed the clinical and neurophysiological diagnosis or not. Results: US was “contributive” (confirming the electrophysiological diagnosis) in 66.67% of cases (n = 20), providing information about continuity of the nerve, morphological changes after injury as swelling, scar tissue formation, or neuroma formation with sensitivity of 75% compared to the electrodiagnostic studies and accuracy of 66.67%. Conclusion: Ultrasound can be used, when available, as a complementary tool for electrodiagnostic studies to provide anatomical information about the injured nerves in case of complete axonal lesion.