EFFECTS OF SYMPATHETIC ACTIVITY ON THE MICROCIRCULATION IN THE FACIAL NERVE

颞叶骨面神经微循环障碍在Bell麻痹的发病机制中起重要作用。虽然循环障碍的原因机制仍然未知，但据说头部和颈部交感神经系统的活动是微循环系统变化的重要因素。为了检查这种关系，使用狗检查了电刺激、化学阻断和低碳酸血症或高碳酸血症期间交感神经系统活动的变化以及颈总动脉和面神经组织中血流的相关变化。将动物静脉麻醉并插管人工通气。作为颈交感神经活动，电刺激颈胸神经节和作为化学阻滞，局部应用局麻药。换气过度或换气不足引起的低碳酸血症或高碳酸血症。用电磁流量计测量颈总动脉血流变化，用激光多普勒组织血流计测量面神经组织血流变化。在电刺激下，两个区域的血流量都明显减少。相反，当甲哌卡因应用于神经节，血流量显着增加，在这两个领域。高碳酸血症时，颈总动脉血流量增加，而面神经组织血流量减少。低碳酸血症降低颈总动脉血流量，但没有改变面神经组织血流量。这些结果表明，面神经的微循环肯定是受损的颈部交感神经系统的活性升高，和该系统的去神经改善血流。基于这些结果，我们假设交感神经活动与面神经的微循环密切相关。

Micro-circulatory disorders of the facial nerves in the tepmporal bone plays an important role in the pathogenesis of Bell's palsy. Although the mechanism of the cause of circulatory impairment is still unknown, the activities of the sympathetic nervous system in the head and neck are said to be an essential factor in the changes of the micro-circulatory system. To examine this relationship, the changes in the sympathetic nervous system activities during electrical stimulation, chemical blockage, and hypo- or hypercapnia as well as associated changes of blood flow in the common carotid artery and the facial nerve tissue, were examined using dogs. Animal were anesthetized intravenusly and intubated with artificial ventilation. As cervical sympathetic activity, electrical stimulation of the cervicothoracic ganglions and as the chemical blockage, local anesthetics was applied locally. Hypo- or hypercapnia induced by hyper- or hypoventilation. The blood flow changes in the common carotid artery were measured with an electromagnetic flowmeter and those in the facial nerve tissue with a laser Doppler tissue blood flowmeter. Blood flow was markedly decreased in both areas with electrical stimulation. To the contrary, when mepivacaine was applied to the ganglions, blood flow was markedly increased in both areas. With the hypercapnia, the blood flow in the common carotid artery increased, however the tissue blood flow of the facial nerve decreased. The hypocapnia decreased the common carotid arterial blood flow but did not change in the facial nerve tissue blood flow. These findings suggested that the micro-circulation of the facial nerve is definitely impaired with an elevated activity of the cervical sympathetic system, and the denervation of this system improves the blood flow. Based on these results, it was assumed that sympathetic activity is closely related to the micro-circulation of the facial nerve.