Clinical, electrodiagnostic, and sonographic studies in ulnar neuropathy at the elbow

Abstract

The aim of this study was to determine possible correlations between the clinical characteristics, electrophysiological features, and sonographic ulnar-nerve diameter in patients with ulnar neuropathy at the elbow (UNE). We prospectively performed clinical, electrodiagnostic, and sonographic studies in 102 patients having either purely sensory signs (35%) or sensorimotor signs (65%) of UNE. Nerve conduction studies had a sensitivity of 78%, and the addition of sonography increased this to 98%. The diagnostic value of both tests was not different among cases with and without motor deficit. Motor studies with recording from the abductor digiti minimi and first dorsal interosseous muscles were equally sensitive for the detection of conduction block or velocity slowing across the elbow, but the combination yielded more positive cases than when only one study was performed. There were modest negative correlations between the electrodiagnostic parameters and the sonographic ulnar-nerve diameter. Electrodiagnostically and sonographically, there were no significant differences between clinically pure sensory and mixed sensorimotor cases of UNE, except for electrodiagnostic findings suggesting loss of motor axons in cases with motor signs. Almost half the patients with only sensory signs had electromyographic evidence of motor axonal loss. We conclude that, although UNE is clinically heterogeneous, the electrophysiological and sonographic findings are fairly consistent despite the clinical manifestations.

Short‐segment nerve conduction studies in ulnar neuropathy at the elbow

“…3 There could have been a selection bias towards performing shortsegment NCS more often in patients with CB on routine electrodiagnostic studies, because in this study 45% of patients had CB, whereas in a group of 102 patients whom we have studied this percentage was 34%. 3 The site of focal CB or increased latency change was above the medial epicondyle in 52% of the patients, a finding which is in accordance with the study of Herrmann et al 10 In the past, the humeroulnar aponeurotic arcade has been the most common place of ulnar nerve entrapment, 16 but this could not be confirmed by the data of Herrmann et al 10 or by our findings. A disadvantage of our study is that we did not make a comparison with intraoperative findings.…”

“…Unfortunately, the 95% confidence interval of the mean motor nerve conduction velocity across the elbow may vary considerable due to accumulation of distance and latency measurement errors, 13 and isolated differential slowing across the elbow is anyway of limited value as a sole criterion. 3,13 Furthermore, routine NCS cannot discriminate between a lesion at the retroepicondylar groove and the humero-ulnar arcade. Precise localization becomes especially important when surgery is contemplated.…”

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

“…(5,8,9), and it is valuable to ascertain histopathologic tissue changes (5,9). Entrapments at the cubital tunnel can be detected using US based on increased cross-sectional areas (CSA) or thickness of the ulnar nerve (10).…”

Methodology and indications for high-resolution sonography (HRUS) of the nerves

“…At the same time we have to assess the echogenic structure of the cubital nerve (sensitivity 86%, specificity 87%) [16]. simultaneous use of sonography and electrophysiology in CUTs diagnostics significantly increases the diagnostic accuracy [17]. similarly as with carpal tunnel syndrome, ultrasound provides additional information on atypical causes of compression, such as post-traumatic bone lesions and soft tissue swelling, and the presence of ganglions and additional muscle, anconeus epitrochlearis.…”