[Changes in microcirculation in the facial nerve with electrical stimulation and chemical blockade of cervical...

The cervical sympathetic trunks send peripheral branches to the external carotid artery system which in turn provides feeding vessels to the facial nerves. In this study, the changes in the tonus of these trunks and the associated changes in the microcirculation of the facial nerves were studied by electrical stimulation and by chemical blockade of the cervical sympathetic trunks in mongrel dogs. With electrical stimulation, marked increases in arterial blood pressure and the heart rate were observed although the common carotid arterial blood flow and tissue blood flow in facial nerves decreased markedly. This suggests that microcirculation in the facial nerve is definitely impaired by electrical stimulation of the cervical sympathetic trunks and that hypertonicity of the sympathetic nervous system is closely involved in the onset of facial palsy. When chemical blockade was applied to the same trunks, the arterial blood pressure and heart rate showed no significant changes. However, there were marked increases of the blood flow in common carotid artery and facial nerve tissue. This finding of improved microcirculation in the facial nerve after chemical blockade suggests that stellate ganglion block may be a very effective treatment for Bell's palsy.