Department of Neurology, Penn State Health Milton S. Hershey Medical Center, Hershey, Pennsylvania.
Neuromuscular Center, Neurological Institute, Cleveland Clinic Foundation, Cleveland, Ohio.
Muscle Nerve. 2021 May;63(5):690-696. doi: 10.1002/mus.27178. Epub 2021 Mar 4.
Neuromuscular ultrasonography (NMUS) is a valuable adjunct to electrodiagnostic testing for the diagnosis of entrapment neuropathy. The aim of this study was to determine whether diagnostic accuracy of NMUS could be enhanced in patients with unilateral ulnar mononeuropathy at the elbow (UNE) by utilizing side-to-side ulnar nerve cross-sectional area (CSA) ratios.
Retrospective case-control analysis of unilateral UNE cases identified cutoff values for elbow segment ulnar nerve maximum CSA (MCSA) of the symptomatic/asymptomatic limb (M ratio), as well as side-to-side ratios comparing MCSA with ipsilateral CSA at the Guyon canal (E/G), middle forearm (E/F), and middle humerus (E/H). Diagnostic accuracy values were calculated.
The optimal M-ratio cut-off was 1.22 (sensitivity, 92.9%; specificity, 97.8%; accuracy, 95.4%). Optimal cutoffs for inter-E/G, -E/F, and -E/H ratios were 1.07 (sensitivity, 98%; specificity, 78%; accuracy, 87.7%), 1.11 (sensitivity, 95%; specificity, 80%; accuracy, 87.2%), and 1.18 (sensitivity, 95%; specificity, 93%; accuracy, 94%), respectively.
The M ratio and inter-E/H ratio exhibited high diagnostic accuracy for unilateral UNE. Prospective studies are needed to compare the accuracy of the new measures with a single MCSA measurement.
神经肌肉超声（NMUS）是诊断嵌压性神经病的电诊断测试的重要辅助手段。本研究旨在通过利用尺神经横截面面积（CSA）的双侧比值，确定在肘单侧尺神经卡压（UNE）患者中，NMUS 的诊断准确性是否可以提高。
回顾性单侧 UNE 病例对照分析确定了症状/无症状侧肘段尺神经最大 CSA（MCSA）的比值（M 比值）的截断值，以及与同侧 Guyon 管（E/G）、前臂中段（E/F）和肱中段（E/H）CSA 比较的双侧比值。计算了诊断准确性值。
最佳 M 比值截断值为 1.22（灵敏度 92.9%，特异性 97.8%，准确性 95.4%）。最佳 E/G、E/F 和 E/H 比值的截断值分别为 1.07（灵敏度 98%，特异性 78%，准确性 87.7%）、1.11（灵敏度 95%，特异性 80%，准确性 87.2%）和 1.18（灵敏度 95%，特异性 93%，准确性 94%）。
M 比值和 E/H 比值对单侧 UNE 具有较高的诊断准确性。需要前瞻性研究来比较新指标与单一 MCSA 测量的准确性。
