Inspiratory muscle activation via ventral lower thoracic high-frequency spinal cord stimulation
Inspiratory muscle activation via ventral lower thoracic high-frequency spinal cord stimulation
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DOI：
10.1152/japplphysiol.01054.2018
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发表时间：
2019-04-01
影响因子：
3.3
通讯作者：
DiMarcom, Anthony F.
中科院分区：
文献类型：
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作者：
Kowalski, Krzysztof E.;Romaniuk, Janislaw Richard;DiMarcom, Anthony F.
在动物中，在 T-2 水平的腹侧硬膜外表面施加高频脊髓刺激 (HF-SCS) 会产生与吸气肌激活一致的气道负压。在本研究中，在麻醉狗中，我们发现在所有胸部水平应用腹侧 HF-SCS（500 Hz）会导致气道负压的产生。在下胸段脊髓区域，气道负压的产生在 T-9 水平最为明显。在此水平上，监测气道压力的产生：1) 在腹侧 HF-SCS 期间，在各种刺激幅度 (0.5-15 mA) 和频率 (50-1,000 Hz) 下进行，2) 在 C-8 处进行脊柱切片（以评估潜在的膈肌激活），随后在 T-6 处进行脊柱切片（以评估潜在的肋间肌激活）。 1 至 2 mA 之间的低刺激电流和高刺激频率 (>300 Hz) 的应用导致了大气道负压的产生。 1 mA、500 Hz 的刺激可产生最高 47 +/- 2 cmH(2)O 的气道负压。增加刺激电流与气道负压产生程度的逐渐减少相关。 15 mA 的 HF-SCS (500 Hz) 导致产生 7 +/- 3 cmH(2)O 的气道负压。 C-8 部分显着减少了气道负压的产生，随后的 T-6 部分导致 HF-SCS 后气道正压的产生。我们的结果表明存在与下胸脊髓腹侧的膈和吸气肋间运动神经元池相连的通路。我们推测介导先前描述的兴奋性肋间膈反射的回路介导了观察到的反应。新的和值得注意的这项研究表明，与 T-9 脊髓水平的背侧高频脊髓刺激相比，这会导致正压产生，而同一脊髓水平的腹侧高频脊髓刺激会导致低刺激电流产生大的气道负压。因此，该方法可能为依赖呼吸机的脊髓损伤患者恢复通气提供另一种方法。
In animals, high-frequency spinal cord stimulation (HF-SCS) applied on the ventral epidural surface at the T-2 level results in negative airway pressure generation consistent with inspiratory muscle activation. In the present study, in anesthetized dogs, we found that ventral HF-SCS (500 Hz) applied at all thoracic levels resulted in negative airway pressure generation. In the region of the lower thoracic spinal cord, negative airway pressure generation was most pronounced at the T-9 level. At this level, airway pressure generation was monitored: 1) during ventral HF-SCS over a wide range of stimulus amplitudes (0.5-15 mA) and frequencies (50-1,000 Hz) and 2) following spinal sections at C-8 (to assess potential diaphragm activation) and subsequently at T-6 (to assess potential intercostal muscle activation). The application of low stimulus currents between 1 and 2 mA and high stimulus frequencies (>300 Hz) resulted in the development of large negative airway pressure generation. Stimulation with 1 mA, 500 Hz resulted in a highest negative airway pressure generation of 47 +/- 2 cmH(2)O. Increasing stimulus current was associated with progressive reductions in the magnitude of negative airway pressure generation. HF-SCS (500 Hz) with 15 mA resulted in a negative airway pressure generation of 7 +/- 3 cmH(2)O. C-8 section markedly reduced negative airway pressure generation, and subsequent T-6 section resulted in positive airway pressure generation after HF-SCS. Our results indicate the existence of pathways with connections to both the phrenic and inspiratory intercostal motoneuron pools in the ventral part of the lower thoracic spinal cord. We speculate that the circuits mediating the previously described excitatory intercostal-to-phrenic reflex mediate the observed responses.NEW & NOTEWORTHY This study suggests that, in contrast to dorsal high-frequency spinal cord stimulation at the T-9 spinal level, which results in positive pressure generation, ventral high-frequency spinal cord stimulation at the same spinal level results in large negative airway pressure generation with low stimulus currents. This method, therefore, may provide an alternative method to restore ventilation in ventilator-dependent spinal cord-injured patients.