International Collaboration on Repair Discoveries (ICORD), Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada; Division of Physical Medicine & Rehabilitation, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
Division of Plastic Surgery, Tory Trauma Program, Sunnybrook Health Sciences Centre, Toronto, Ontario; Division of Plastic, Reconstructive and Aesthetic Surgery, Department of Surgery, University of Toronto, Toronto, Ontario.
Arch Phys Med Rehabil. 2024 Apr;105(4):682-689. doi: 10.1016/j.apmr.2023.11.003. Epub 2023 Nov 17.
To use the ulnar compound muscle action potential (CMAP) to abductor digiti minimi (ADM) to identify the proportion of individuals with cervical spinal cord injury (SCI) who have lower motor neuron (LMN) abnormalities involving the C8-T1 spinal nerve roots, within 3-6 months, and thus may influence the response to nerve transfer surgery.
Retrospective analysis of prospectively collected data. Data were analyzed from European Multicenter Study About SCI database.
Multi-center, academic hospitals.
We included 79 subjects (age=41.4±17.7, range:16-75; 59 men; N=79), who were classified as cervical level injuries 2 weeks after injury and who had manual muscle strength examinations that would warrant consideration for nerve transfer (C5≥4, C8<3).
None.
The ulnar nerve CMAP amplitude to ADM was used as a proxy measure for C8-T1 spinal segment health. CMAP amplitude was stratified into very abnormal (<1.0 mV), sub-normal (1.0-5.9 mV), and normal (>6.0 mV). Analysis took place at 3 (n=148 limbs) and 6 months (n=145 limbs).
At 3- and 6-month post-injury, 33.1% and 28.3% of limbs had very abnormal CMAP amplitudes, respectively, while in 54.1% and 51.7%, CMAPs were sub-normal. Median change in amplitude from 3 to 6 months was 0.0 mV for very abnormal and 1.0 mV for subnormal groups. A 3-month ulnar CMAP <1 mV had a positive predictive value of 0.73 (95% CI 0.69-0.76) and 0.78 (95% CI 0.75-0.80) for C8 and T1 muscle strength of 0 vs 1 or 2.
A high proportion of individuals have ulnar CMAPs below the lower limit of normal 3- and 6-month post cervical SCI and may also have intercurrent LMN injury. Failure to identify individuals with LMN denervation could result in a lost opportunity to improve hand function through timely nerve transfer surgeries.
利用尺神经复合肌肉动作电位（CMAP）至小指展肌（ADM）来识别在颈脊髓损伤（SCI）后 3-6 个月内，哪些个体存在涉及 C8-T1 脊神经根的下运动神经元（LMN）异常，这些异常可能会影响神经转移手术的反应。
前瞻性收集数据的回顾性分析。数据来自欧洲多中心 SCI 研究数据库。
多中心，学术医院。
我们纳入了 79 名受试者（年龄=41.4±17.7，范围：16-75；59 名男性；N=79），他们在损伤后 2 周被分类为颈段损伤，且手部肌力检查需要考虑进行神经转移（C5≥4，C8<3）。
无。
尺神经 CMAP 幅度至 ADM 用作 C8-T1 脊髓节段健康的替代指标。CMAP 幅度分为非常异常（<1.0 mV）、亚正常（1.0-5.9 mV）和正常（>6.0 mV）。分析在 3 个月（n=148 肢体）和 6 个月（n=145 肢体）时进行。
在损伤后 3 个月和 6 个月时，分别有 33.1%和 28.3%的肢体出现非常异常的 CMAP 幅度，而在 54.1%和 51.7%的肢体中，CMAP 幅度为亚正常。从 3 个月到 6 个月，非常异常组和亚正常组的 CMAP 幅度中位数变化分别为 0.0 mV 和 1.0 mV。3 个月时尺神经 CMAP<1 mV 对 C8 和 T1 肌力为 0 与 1 或 2 的阳性预测值分别为 0.73（95%CI 0.69-0.76）和 0.78（95%CI 0.75-0.80）。
在颈脊髓损伤后 3-6 个月，相当一部分个体的尺神经 CMAP 低于正常下限，并且可能还存在并发的 LMN 损伤。未能识别存在 LMN 去神经支配的个体可能会错失通过及时神经转移手术改善手部功能的机会。
