Introduction: Peripheral compression neuropathy of the ulnar nerve is a frequent condition, most likely encountered at the ulnar sulcus or the Guyon's canal. High-resolution ultrasound (HRUS) can often identify the site of injury. Primarily idiopathic, compression neuropathy can stem from a punched nerve syndrome, in which direct contact between an arterial branch and the nerve leads to compression.
Materials and methods: A 42-year-old male patient was examined by means of HRUS using a 17-5 MHz linear transducer on a Philips iU22(®) (Philips, Bothell, Washington, USA).
Results: After reporting a punched nerve syndrome of the deep motor branch of the ulnar nerve distal to the Guyon's canal, the patient underwent surgery and showed electrophysiological and clinical improvement 6 months after decompression.
Conclusion: HRUS is a viable method to demonstrate a punched nerve syndrome. In conjunction with clinical presentation, even unlikely sites of compression such as the deep motor branch of the ulnar nerve can be identified.