Ultrasound of peripheral nerves in neuralgic amyotrophy

Introduction: Neuralgic amyotrophy (NA) can often be difficult to diagnose. Nerve ultrasound (US) is potentially useful, but it is operator-dependent, especially for small nerves. Methods: Fifty-one consecutive patients with NA (mean duration 16 months) and 50 control subjects underwent US of the brachial plexus and major nerves of the upper extremity at predefined sites. We compared cross-sectional areas (CSAs) of affected and unaffected sides with controls and sides within patients. Results: The median nerve and radial nerve at the level of the upper arm were enlarged on the affected sides compared with controls and the unaffected sides of patients. Enlargement was most pronounced for affected sides vs. controls (median 44%, radial 67%). Discussion: NA patients showed increased CSAs, especially in the major nerves of the upper limb, even after longer disease duration. This could make US a useful adjunct in diagnosing NA. Muscle Nerve 59:55-59, 2019