Department of Surgery and Perioperative Care, Dell Medical School-The University of Texas at Austin, Austin, TX.
Orthopaedic Hand and Upper Extremity Service, Massachusetts General Hospital-Harvard Medical School, Boston, MA.
J Hand Surg Am. 2020 May;45(5):379-388.e1. doi: 10.1016/j.jhsa.2019.11.020. Epub 2020 Feb 20.
Patient knowledge of the frequency with which electrodiagnostic testing (EDx) for suspected median neuropathy at the carpal tunnel addresses nuance in the distinction between normal and abnormal neurophysiology might help them make an informed decision about whether or not to have this test. We reviewed a large set of consecutive EDx for possible carpal tunnel syndrome (CTS) and associated medical records to determine (1) the percentage of EDx measurements within 10% of threshold values; (2) discordance between clinician and EDx diagnosis of CTS using diagnostic performance characteristics; and (3) demographic and disease characteristics independently associated with EDx diagnosis of median neuropathy at the carpal tunnel.
We retrospectively reviewed nerve conduction study (NCS) results of 537 consecutive patients evaluated for possible idiopathic median neuropathy at the carpal tunnel. We measured the number of patients within 10% of 3 NCS diagnostic thresholds; the diagnostic performance characteristics comparing clinician and EDx diagnosis; and patient and disease characteristics associated with EDx diagnosis of CTS.
The 3 NCS parameters were within 10% of the threshold for diagnosis of median neuropathy at the carpal tunnel in 2.6% to 33% of patients. Overall, 76% of EDx results were interpreted as median neuropathy at the carpal tunnel, 19% as normal, and 5% as another diagnosis (eg, cervical radiculopathy). Patients with normal EDx were significantly younger, more likely not to report paresthesias/numbness, more likely to have prior normal EDx, and less likely to have had a previous contralateral carpal tunnel release.
This data set reflecting management strategies for suspected CTS at a large institution confirms inherent diagnostic uncertainty, relatively strong concordance between clinician and EDx diagnosis, and the importance of focusing on paresthesia rather than pain. These findings support the use of clinical prediction rules and may help inform a patient's decision regarding whether or not to have EDx.
TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic III.
患者对疑似腕管正中神经电诊断测试（EDx）频率的了解，可能有助于他们在是否进行这项测试方面做出明智的决定，因为这种测试可以区分正常和异常神经生理学。我们回顾了大量连续进行的 EDx，以确定可能的腕管综合征（CTS）和相关的医疗记录，以确定：（1）EDx 测量值在阈值的 10%以内的百分比；（2）使用诊断性能特征，比较临床医生和 EDx 对 CTS 的诊断结果之间的差异；（3）独立与 EDx 诊断正中神经在腕管中发生病变相关的人口统计学和疾病特征。
我们回顾性分析了 537 例连续评估疑似腕管正中神经病变患者的神经传导研究（NCS）结果。我们测量了 3 个 NCS 诊断阈值中 10%以内的患者数量；比较临床医生和 EDx 诊断的诊断性能特征；以及与 EDx 诊断 CTS 相关的患者和疾病特征。
在 2.6%至 33%的患者中，3 个 NCS 参数在腕管正中神经病变的诊断阈值的 10%以内。总体而言，76%的 EDx 结果被解释为腕管正中神经病变，19%为正常，5%为其他诊断（如颈椎神经根病）。EDx 结果正常的患者明显更年轻，更不可能报告感觉异常/麻木，更有可能之前有正常的 EDx，并且不太可能之前对侧腕管松解术。
该数据集反映了大型机构对疑似 CTS 的管理策略，证实了固有的诊断不确定性、临床医生和 EDx 诊断之间相对较强的一致性，以及关注感觉异常而不是疼痛的重要性。这些发现支持使用临床预测规则，并可能有助于告知患者是否进行 EDx 的决定。
研究类型/证据水平：诊断 III 级。
