Ultrasound of Focal Neuropathies.

Focal neuropathies represent the most common indication for referral to electrodiagnostic laboratories. The etiologies range from chronic compression, as might be seen in carpal tunnel syndrome, to acute traumatic nerve injuries that require rapid intervention. The gold standard for diagnosis, electrodiagnostic testing, cannot provide the complementary anatomical information necessary to guide accurate diagnosis and treatment. An expanding body of literature supports the use of neuromuscular ultrasound as a standard component for evaluating focal neuropathies. In the current review, the role of ultrasound in both common and unusual compression neuropathies is reviewed, along with the use of ultrasound in traumatic nerve injury. The evidence demonstrates that nerve ultrasound has an essential, complementary role with electrodiagnostic testing.