Utility of nerve ultrasound in ulnar neuropathy with abnormal non-localizing electrophysiology in diabetes mellitus.

We studied the utility of ultrasound in the diagnostic workup of ulnar neuropathy with abnormal non-localizing electrophysiology (NL-UN) in patients with diabetes. Eighteen ulnar nerves (15 patients) were scanned from wrist to mid-upper arm. Ultrasound showed: (a) focal nerve enlargement at the elbow (8/18 nerves), either alone (6) or superimposed upon diffuse nerve abnormality (2); (b) diffuse nerve enlargement without focal abnormality (8/18); (c) segmental abnormality in upper-arm or forearm without extrinsic nerve compression (2/18). This study shows a pivotal role for ultrasound in the classification of NL-UN in patients with diabetes, which can facilitate critical therapeutic decisions.