Parkhurst Drew B, Andary Michael T, Powell John W
Department of Physical Medicine and Rehabilitation, Michigan State University, Lansing, Michigan, United States.
J Brachial Plex Peripher Nerve Inj. 2020 Aug 26;15(1):e16-e21. doi: 10.1055/s-0040-1714742. eCollection 2020 Jan.
Diagnosing ulnar neuropathy at the elbow (UNE) remains challenging despite guidelines from national organizations. Motor testing of hand intrinsic muscles remains a common diagnostic method fraught with challenges. The aim of the study is to demonstrate utility of an uncommon nerve conduction study (NCS), mixed across the elbow, when diagnosing UNE. Retrospective analysis of 135 patients, referred to an outpatient University-based electrodiagnostic laboratory with suspected UNE between January 2013 and June 2019 who had motor to abductor digiti minimi (ADM), motor to first dorsal interosseus (FDI), and mixed across the elbow NCS completed. To perform the mixed across the elbow NCS, the active bar electrode was placed 10-cm proximal to the medial epicondyle between the biceps and triceps muscle bellies. The median nerve was stimulated at the wrist followed by stimulation of the ulnar nerve at the ulnar styloid. The difference between peak latencies, labeled the ulnar-median mixed latency difference (U-MLD), was used to evaluate for correlation between the nerve conduction velocities (NCV) of ADM and FDI. Pearson -values = -0.479 and -0.543 ( < 0.00001) when comparing U-MLD to ADM and FDI NCV across the elbow, respectively. The negative -value describes the inverse relationship between ulnar velocity across the elbow and increasing U-MLD. Mixed across the elbow has moderate-strong correlation with ADM and FDI NCV across the elbow. All three tests measure ulnar nerve function slightly differently. Without further prospective data, the most accurate test remains unclear. The authors propose some combination of the three tests may be most beneficial when diagnosing UNE.
尽管有国家组织发布的指南，但诊断肘部尺神经病变（UNE）仍然具有挑战性。对手部固有肌进行运动测试仍然是一种常见的诊断方法，但充满了挑战。
本研究的目的是证明一种不常见的神经传导研究（NCS），即肘部混合神经传导研究，在诊断UNE时的实用性。
对2013年1月至2019年6月期间转诊至一家大学门诊电诊断实验室、疑似患有UNE的135例患者进行回顾性分析，这些患者均完成了小指展肌（ADM）运动、第一背侧骨间肌（FDI）运动以及肘部混合神经传导研究。为了进行肘部混合神经传导研究，将活动条形电极置于肱骨内上髁近端10厘米处，位于肱二头肌和肱三头肌肌腹之间。先刺激腕部的正中神经，然后刺激尺骨茎突处的尺神经。峰潜伏期之间的差异，标记为尺神经-正中神经混合潜伏期差异（U-MLD），用于评估ADM和FDI的神经传导速度（NCV）之间的相关性。
将U-MLD分别与肘部ADM和FDI的NCV进行比较时，Pearson相关系数值分别为-0.479和-0.543（P＜0.00001）。负相关系数值描述了肘部尺神经速度与U-MLD增加之间的反比关系。
肘部混合神经传导研究与肘部ADM和FDI的NCV具有中度至强相关性。这三种测试对尺神经功能的测量略有不同。在没有进一步前瞻性数据的情况下，最准确的测试仍不明确。作者提出，在诊断UNE时，这三种测试的某种组合可能最有益。
