Ultrasonography in patients with ulnar neuropathy at the elbow: Comparison of cross‐sectional area and swelling ratio with electrophysiological severity

Abstract

The aim of this study was to determine the diagnostic value of ultrasonographic measurements in ulnar neuropathy at the elbow (UNE) and to assess the relationship between the measurements and the electrophysiological severity. The largest anteroposterior diameter (LAPD) and cross-sectional area (CSA) measurements of the ulnar nerve were noted at multiple levels along the arm, and the distal-to-proximal ratios were calculated. Almost all of the measurements and swelling ratios between patients and controls showed statistically significant differences. The largest CSA, distal/largest CSA ratio, CSA at the epicondyle, and proximal LAPD had larger areas under the curve than other measurements. The sensitivity and specificity in diagnosing UNE were 95% and 71% for the largest CSA, 83% and 85% for the distal/largest CSA ratio, 83% and 81% for the CSA at the epicondyle, and 93% and 43% for the proximal LAPD, respectively. There was a statistically significant correlation between the electrophysiological severity scale score (ESSS) and the largest CSA, the CSA at the epicondyle and 2 cm proximal to the epicondyle, and the LAPD at the level of the epicondyle (P < 0.05). None of the swelling ratios showed a significant correlation with the ESSS. The largest CSA measurement is the most valuable ultrasonographic measurement both for diagnosis and determining the severity 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.…”

“…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).…”

“…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.…”

New technologies for the assessment of neuropathies

“…When the ulnar nerve is trapped at the elbow, swelling of the nerve can be detected close to the entrapment site 45,46 (FIG. 2).…”

MR neurography of ulnar nerve entrapment at the cubital tunnel: a diffusion tensor imaging study

“…Neurosonography and MRI are established tools for visualizing the location of the ulnar nerve lesion and its underlying mechanism [3][4][5][6]. Intraneural oedema, peripheral nerve demyelination and nerve fibre degeneration cause an increase in the local T2-weighted MR signal intensity of a mechanically compressed or irritated nerve segment [7].…”