Rhabdomyolysis resulting in concurrent Horner’s syndrome and brachial plexopathy: a case report

This case report describes a 29-year-old male who presented with immediate onset of Horner’s syndrome and ipsilateral brachial plexopathy after sleeping with his arm dangling outside a car window for 8 h. Outside workup and imaging revealed rhabdomyolysis of the left neck musculature. Subsequent electrodiagnostic testing and high-resolution brachial plexus magnetic resonance imaging at the authors’ institution attributed the Horner’s syndrome and concurrent brachial plexopathy to rhabdomyolysis of the longus colli and scalene musculature, which had compressed—and consequently scar tethered—the cervical sympathetic trunk and brachial plexus. This case of co-existent Horner’s syndrome and brachial plexopathy demonstrates the role of high-resolution brachial plexus MRI in diagnosing plexopathy and the importance of being familiar with plexus and paravertebral muscle anatomy.