The Relationship Between Magnetic Resonance Imaging and Electrodiagnostic Studies in Patients with Ulnar Neuropathy at the Elbow

Abstract

Objective: This study investigated the correlations between magnetic resonance imaging (MRI) and nerve conduction studies (NCS) in patients with ulnar neuropathy at the elbow (UNE).

Methods: In total, 46 patients who underwent elbow MRI and NCS at a single center from 2014 to 2018 were included. Motor studies, including segmental and inching tests, and sensory NCS were performed. The 5-point severity score was evaluated based on the signal change and swelling in the fat-suppressed T2 weighted sequence. The findings of MRI and NCS were grouped into 3 categories. The Spearman rank test was used to evaluate correlations between the severity score on MRI and electrodiagnostic parameters.

Results: The locations of the lesions on MRI and NCS were correlated in 20 of the 46 patients with UNE, while the other 20 patients had no correlations. Six patients who could not be categorized according to the location showed various findings. The severity score based on MRI showed significant negative correlations with amplitude on the segmental study (r = –0.423, p =0.002) and the inching study (r = –0.456, p = 0.002), and with conduction velocity in the segmental study (r = –0.526, p < 0.001) and the inching study (r = –0.548, p < 0.001).

Conclusion: Electrodiagnostic outcomes had negative correlations with the severity score, reflecting the structural changes seen on MRI. Combining electrodiagnostic studies and MRI could make the diagnosis and localization more precise.