Ultrasound diagnosis of ulnar neuropathy: Comparison of symptomatic and asymptomatic nerve thickness

Abstract

There is still no consensus on a normal value for the cross-sectional area of the ulnar nerve at the elbow. Such data would be valuable for the ultrasound diagnosis of ulnar neuropathy. Comparison of the symptomatic and contralateral asymptomatic sides has been recommended. The aim of this study was to investigate whether or not the asymptomatic ulnar nerve could be a reference value. High-resolution ultrasonic measurements of the cross-sectional areas of the ulnar nerves at the elbow were compared with 38 contralateral asymptomatic elbows of patients with unilateral ulnar neuropathy and 38 healthy controls. There were significant differences in the cross-sectional areas at all levels between the healthy control subjects and asymptomatic side of the ulnar neuropathy patients (p < 0.05). The findings of this study suggest that there is a limitation in using the asymptomatic side for obtaining reference values in ultrasonographic studies. Each ultrasonographic laboratory should determine its own reference values.

Reference values for ultrasonograpy of peripheral nerves

“…The results are comparable to published values for most sites. For example, our result for the CSA of the ulnar nerve in the Guyon canal was 5.0 ± 1.7 mm 2 , and this value is very close to that of Yalcin et al . who found 4.9 ± 0.6 mm 2 and Kerasnoudis et al .…”

Diagnostic Cutoff Value for Ultrasonography of the Common Fibular Neuropathy at the Fibular Head

“…To overcome these discrepancies, in clinical practice, the healthy contralateral side is often used as an internal control [222324]. Some previous studies described upper limit value of the side-to-side difference [6922]; in addition, one study showed no significant correlation with subjects' baseline demographic factors including age, height, weight, and BMI in CF nerve [9].…”

“…Although ΔSx–Asx was a useful and reliable value, it is not applicable to bilateral lesions or diffuse nerve pathology [222324]. Therefore, the ratio of nerve CSA has also been analyzed and proposed as a complementary value [252627].…”

Ultrasound in the diagnosis and management of fibular mononeuropathy

“…There has been debate in the literature about use of the asymptomatic contralateral limb as an internal control . Also noteworthy is that time may erode the CSA size/nerve‐injury‐severity relationship.…”