From the Section of Plastic Surgery, Department of Surgery, University of Michigan Medical School.
the Department of Biostatistics, School of Public Health, University of Michigan.
Plast Reconstr Surg. 2023 Jun 1;151(6):1247-1255. doi: 10.1097/PRS.0000000000010163. Epub 2023 Jan 3.
Ulnar neuropathy at the elbow (UNE) is a debilitating upper extremity condition that often leaves patients with residual symptoms even after surgical treatment. The role of electrodiagnostic studies in guiding the treatment of UNE is not well established, and conventional electrodiagnostic parameters may not reflect the severity of disease. Compound muscle action potential (CMAP) amplitude is a parameter that corresponds with axonal injury and motor symptoms and may more accurately predict the severity of neurologic injury.
This prospective multicenter study recruited 78 patients in the Surgery of the Ulnar Nerve project. Patients underwent electrodiagnostic testing and clinical assessment of motor and sensory function, and completed patient-reported outcome questionnaires, including the Michigan Hand Outcome Questionnaire; the Disabilities of the Arm, Shoulder and Hand questionnaire; and the Carpal Tunnel Questionnaire (CTQ). Correlations were measured among each of the electrodiagnostic parameters and outcomes and predictive models for each outcome were subsequently developed.
Of all the electrodiagnostic parameters measured, only CMAP amplitude was predictive of scores on the Michigan Hand Outcome Questionnaire; Disabilities of the Arm, Shoulder and Hand questionnaire; CTQ function scale, and motor impairment in grip and pinch strength. None of the parameters were predictive of scores on the CTQ symptom scale or sensory impairments as measured with two-point discrimination or Semmes-Weinstein monofilament testing.
CMAP amplitude, but not other conventional electrodiagnostic parameters, is predictive of functional outcomes in UNE. This electrodiagnostic measurement can alert the clinician to severe cases of UNE and inform surgical decision-making.
CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.
肘部尺神经病变（UNE）是一种使人衰弱的上肢疾病，即使经过手术治疗，患者仍常遗留症状。电诊断研究在指导UNE 治疗中的作用尚未得到充分确立，且常规电诊断参数可能无法反映疾病的严重程度。复合肌肉动作电位（CMAP）幅度是与轴索损伤和运动症状相对应的参数，可能更准确地预测神经损伤的严重程度。
这项前瞻性多中心研究招募了“Surgery of the Ulnar Nerve”项目中的 78 名患者。患者接受电诊断测试和运动及感觉功能的临床评估，并完成包括密歇根手功能问卷、肩肘手残疾问卷和腕管问卷（CTQ）在内的患者报告结局问卷。测量了每种电诊断参数与结局之间的相关性，随后为每种结局建立了预测模型。
在所测量的所有电诊断参数中，只有 CMAP 幅度与密歇根手功能问卷、肩肘手残疾问卷、CTQ 功能量表和握力、捏力运动障碍的评分相关。没有任何参数与 CTQ 症状量表评分或两点辨别觉或 Semmes-Weinstein 单丝测试的感觉障碍相关。
CMAP 幅度，但不是其他常规电诊断参数，可预测 UNE 的功能结局。这种电诊断测量可以提醒临床医生注意严重的 UNE 病例，并为手术决策提供信息。
临床问题/证据水平：风险，III 级。
