001 Ulnar neuropathy with abnormal non-localising electrophysiology: clinical, electrophysiological and ultrasound findings

Introduction Ulnar neuropathy with abnormal non-localising electrophysiology (NL-UN) is often associated with significant disability that is difficult to manage due to the absence of anatomically defining studies. We studied demographic, clinical and electrophysiological characteristics of NL-UN and used ultrasound in order to assist with classification and to examine the utility of ultrasound over and above the conventional electro-diagnostic approach. Method NL-UNs were identified from 113 consecutive referrals to a single neurophysiologist with suspected ulnar neuropathy. All received systematic electro-diagnostic tests and ulnar nerve ultrasound. NL-UN severity was graded using clinical and electrophysiological scales. Results In 64 of 113 referrals, an ulnar mononeuropathy was confirmed by electrophysiology. Sixteen of these 64 (25%) had NL-UN, predominantly males (14 out of 16 patients) with severe or moderately severe clinical and electrophysiological ratings in 81%. Ultrasound showed focal ulnar neuropathy at the elbow (UNE) in 13 out of 16, and diffuse ulnar nerve abnormality in three, and identified a likely or possible causative mechanism in 11 UNEs. Conclusion A quarter of ulnar neuropathies, as demonstrated by abnormal electrophysiology, were NL-UN, of heterogeneous aetiology; the majority were males with significant disability and axonal loss. Ultrasound had a significant role in localization and classification of NL-UN that facilitated management.