Individuals classified clinically as having a motor-complete spinal cord injury (mcSCI) should lack voluntary motor function below their injury level. Neurophysiological assessments using electromyography (EMG) and transcranial magnetic stimulation (TMS), however, have demonstrated that persons with mcSCI retain limited cortical descending innervation and voluntary activation of muscles below their level of injury, including muscles of the trunk and lower limb. We explored the possibility of whether there is also preserved innervation of the pelvic floor muscles (PFM) in persons with mcSCI. The PFM are controlled by widespread cortical and subcortical areas and typically coactivated with trunk and gluteal muscles to maintain continence and regulate intra-abdominal pressure. Nine mcSCI and eight control subjects participated in this cross-sectional study. Surface EMG was used to record activity in the PFM. Data were recorded while participants attempted various maneuvers of the trunk and pelvis. We also applied TMS at incrementing levels of intensity over the primary motor cortex area to record motor evoked potentials (MEPs) in the PFM. When performing the maneuvers, activation of the PFM was possible in all controls and the majority of SCI participants. However, the PFM were only activated in the SCI participants during maneuvers that engaged other trunk muscles, however. MEP responses in the PFM were also elicited in all controls and SCI participants, but MEP response characteristics were significantly altered in the SCI group. Our results suggest that persons with mcSCI retain some residual innervation of the PFM after injury, possibly via indirect cortical descending pathways.

中文翻译：

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运动完全性脊髓损伤患者盆底肌肉的残余神经支配。

临床上归类为运动完全性脊髓损伤 (mcSCI) 的个体应在其损伤水平以下缺乏自主运动功能。然而，使用肌电图 (EMG) 和经颅磁刺激 (TMS) 的神经生理学评估表明，mcSCI 患者保留有限的皮质下行神经支配和损伤水平以下肌肉的自主激活，包括躯干和下肢的肌肉。我们探讨了 mcSCI 患者骨盆底肌肉 (PFM) 是否也有保留的神经支配的可能性。PFM 由广泛的皮层和皮层下区域控制，通常与躯干和臀肌共同激活以保持节制和调节腹内压。九名 mcSCI 和八名对照受试者参与了这项横断面研究。表面肌电图用于记录 PFM 中的活动。在参与者尝试对躯干和骨盆进行各种动作时记录数据。我们还在初级运动皮层区域以递增的强度水平应用 TMS，以记录 PFM 中的运动诱发电位 (MEP)。在执行操作时，所有控件和大多数 SCI 参与者都可以激活 PFM。然而，PFM 仅在参与其他躯干肌肉的演习期间在 SCI 参与者中被激活，然而。PFM 中的 MEP 反应也在所有对照和 SCI 参与者中引起，但 MEP 反应特征在 SCI 组中显着改变。