Diagnostic Value of Ultrasonography and Magnetic Resonance Imaging in Ulnar Neuropathy at the Elbow

Abstract

Aim. To evaluate the diagnostic value of ultrasonography and magnetic resonance imaging (MRI) in patients with ulnar neuropathy at the elbow (UNE). Methods. We prospectively performed electrodiagnostic, ultrasonographic, and MRI studies in UNE patients and healthy controls. Three cross-sectional area (CSA) measurements of the ulnar nerve at multiple levels along the arm and maximum CSA(-max) were recorded. Results. The ulnar nerve CSA measurements were different between the UNE severity grades (P < 0.05). CSA-max had the greatest sensitivity (93%) and specificity (68%). Moreover, CSA-max ≥10 mm2 defined the severe UNE cases (sensitivity/specificity: 82%/72%). In MRI, ulnar nerve hyperintensity had the greatest sensitivity (90%) and specificity (80%). Conclusion. Ultrasonography using CSA-max is sensitive and specific in UNE diagnosis and discriminating the severe UNE cases. Furthermore, MRI particularly targeting at increased signal of the ulnar nerve can be a useful diagnostic test of UNE.

Reproducibility of Ultrasonographic Measurements of the Ulnar Nerve at the Cubital Tunnel

“…Statistical significant differences of the outcomes of the CSA of the ulnar nerve in both groups were found in all the three studies (21,26,27). In these studies the CSA of the ulnar nerve increases with 56% (26), 75% (27) and 192% (21), in individuals diagnosed with UNE compared to healthy individuals. Considering these detected increases of the CSA, it can be presumed that an entrapped nerve will transcend the SDC found in the current study.…”

“…Care has to be taken when relating the SDC of this study to the statistical significant changes of the three previous studies, because measurement protocols differed. For example the elbow flexion ranged from 15° (21,26) to 70-80° in the cu rrent study and 90° (27). Further research is needed to determine whether different test positions influence the SDC.…”

“…This may result in varying representations of the ulnar nerve and a higher chance of subluxation of the ulnar nerve (28). In previous studies the measurements were performed in 90° up to full flexion (16)(17)(18)22,27,29). Consequently varying means of the CSA were stated from 4 mm 2 (27) to 7.9 mm 2 (29).…”

“…The purpose of the current study was to determine the inter-and intra-rater reliability as (21,26,27). Statistical significant differences of the outcomes of the CSA of the ulnar nerve in both groups were found in all the three studies (21,26,27).…”

Diagnosis and Treatment of Work-Related Ulnar Neuropathy at the Elbow

“…[15][16][17][18] However, the clinical utility of these tests has not yet been proven. Although these tests may be useful in unusual circumstances in which NCV results are normal but there are appropriate clinical symptoms, at this time the use of these tests should be considered investigational and used only in a research setting.…”