Quantitative assessment of nerve echogenicity: comparison of methods for evaluating nerve echogenicity in ulnar neuropathy at the elbow

A comparison of ultrasonographic and electrophysiologic 'inching' in ulnar neuropathy at the elbow

OBJECTIVE

The present study aimed to clarify the relationship between structural ulnar nerve changes and electrophysiological nerve dysfunction in patients with ulnar neuropathy at the elbow (UNE).

METHODS

High-resolution ultrasonography of the ulnar nerve was performed on 17 limbs with clinically and electrophysiologically confirmed UNE, and 52 control subjects at four standardised sites proximal and distal to the medial epicondyle (P2, P1, D1, D2), corresponding to segments of ulnar short-segment nerve conduction studies ("inching studies").

RESULTS

Ulnar nerve cross-sectional area (CSA) and hypoechoic fraction were significantly increased in patients with UNE immediately distal (D1) and proximal (P1) to the medial epicondyle (p<0.01). In patients with UNE, hypoechoic fraction was similar in asymptomatic and symptomatic limbs. Motor nerve conduction velocity across the elbow correlated with CSAmax and the maximum hypoechoic fraction (R=0.6, p<0.05). CSA and hypoechoic fraction of individual segments did not correlate with corresponding latencies on inching studies, but latencies across the D1 segment correlated with CSA at P1 (R=0.80, p<0.0001) and D2 (R=0.65, p<0.01).

CONCLUSIONS

Sonographic abnormalities in UNE may not be maximal at the site of electrophysiological nerve dysfunction.

SIGNIFICANCE

Sonographic abnormalities may reflect secondary pathophysiological changes in segments adjacent to regions of nerve compression.

Diagnostic value of high-resolution sonography in common fibular neuropathy at the fibular head

INTRODUCTION

In 30% of patients with common fibular (CF) neuropathy at the fibular head, reliable localization of the site of the lesion by means of electrodiagnostic testing is challenging.

METHODS

We prospectively assessed proximal CF nerve cross-sectional area (CSA) measurements and at the fibular head in 87 patients with CF neuropathy and 16 with a different condition. Reference values were obtained in 64 healthy volunteers.

RESULTS

Patients with CF neuropathy had a significantly larger CF nerve CSA than controls and patient controls (P < 0.0001). Sonography localized the lesion at the fibular head in 55% and just above it in 71% of patients. Assessment of the most thickened part of the CF nerve resulted in a cut-off value of >8 mm² with a sensitivity of 90% (CI 81-95%) and a specificity of 69% (CI 58-78%).

CONCLUSION

High-resolution sonography in addition to electrodiagnostic testing improves diagnostic reliability in CF neuropathy.

Ultrasonography of peripheral nerves

Over the last decade, neuromuscular ultrasonography has emerged as a useful tool for the diagnosis of peripheral nerve disorders. This article reviews sonographic findings of normal nerves, including key quantitative ultrasound measurements that are helpful in the evaluation of focal and possibly generalized peripheral neuropathies. It also discusses several recent articles outlining the evidence base for the use of this technology, as well as new findings in compressive, traumatic, and generalized neuropathies. Ultrasonography is well suited for use in electrodiagnostic laboratories, where physicians, experienced in both the clinical evaluation of patients and the application of hands-on technology, can integrate findings from the patient's history, physical examination, electrophysiological studies, and imaging for diagnosis and management.

Sonographic incidence of ulnar nerve (sub)luxation and its associated clinical and electrodiagnostic characteristics

INTRODUCTION

The aim of this study was to assess the presence of (sub)luxation of the ulnar nerve in patients with ulnar neuropathy at the elbow (UNE) compared with healthy controls (HC). We assessed its clinical patterns, electrodiagnostic, and sonographic characteristics.

METHODS

Using high-resolution sonography, we studied the incidence of (sub)luxation in a cohort of 342 patients and 70 HC.

RESULTS

Subluxation occurred in 14% and luxation in 6.7% of the UNE patients versus 5.7% and 5.7%, respectively, in HC (no significant differences). Pain at the elbow occurred more often in patients with (sub)luxation (P = 0.007). Electrodiagnostic and sonographic findings did not differ between patients with or without (sub)luxation.

CONCLUSIONS

The incidence of ulnar nerve (sub)luxation between patients with UNE and HC does not differ. UNE patients with (sub)luxation do not have specific clinical or electrodiagnostic findings, apart from experiencing pain at the elbow more often.

Increased nerve vascularization detected by color Doppler sonography in patients with ulnar neuropathy at the elbow indicates axonal damage

INTRODUCTION

The aim of this study was to establish the prevalence of increased intraneural vascularization detected by ultrasonography (IVUS) in patients with ulnar neuropathy at the elbow (UNE) and to determine its relationship to clinical, ultrasonographic, and electrodiagnostic findings.

METHODS

High-resolution ultrasonography and color Doppler imaging were performed in 137 patients with confirmed UNE, 24 patient controls, and 70 healthy controls (HCs).

RESULTS

IVUS was found in 21 (15%) of 137 patients with UNE, in 1 (4%) of 24 patient controls, and in 0 of 70 HCs (P = 0.001). Patients with IVUS were more likely to have severe weakness (P = 0.01), severe atrophy of ulnar-innervated muscles (P = 0.008), axonal damage (P = 0.001), and more pronounced nerve enlargement (P = 0.03) than those without IVUS.

CONCLUSIONS

IVUS in the ulnar nerve can be detected in patients with UNE and is associated with nerve enlargement and clinical and electrodiagnostic severity. In addition, IVUS is associated with axonal damage.