2002 Fiscal Year Final Research Report Summary
Application of the denervation in the cervical sympathetic nervous system for the treatment of facial palsy
| Project/Area Number |
12671511
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Anesthesiology/Resuscitation studies
|
|---|
| Research Institution | Hyogo Medical University |
|---|
Principal Investigator |
MURAKAWA Kazushige HYOGO COLLEGE OF MEDICINE・MEDICINE, PROFESSOR, 医学部, 教授 (70104263)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
NOGAWA Kazuhide HYOGO COLLEGE OF MEDICINE・MEDICINE, RESEARCH ASSOCIATE, 医学部, 助手 (30301659)
|
|---|
| Project Period (FY) |
2000 – 2002
|
| Keywords | facial palsy / stellate ganglion block / facial nervous tissue blood flow / common carotid arterial blood flow / prostaglandin E1 |
|---|
| Research Abstract |
Microcirculatory disorders of the facial nerves in the temporal bone play an important role in the pathogenesis of Bell's palsy. However, the mechanism of onset of circulatory impairment is still unknown. The activity of the sympathetic nervous system in the head and neck is presumed to be an important factor in the changes of the microcirculatory system in the facial nerves. We confirmed that that electrical stimulation given to the cervical sympathetic trunks and hypercapnia induced by hypoventilation decreased the blood flow in facial nerve tissues. In addition, chemical blockage of the cervical sympathetic trunks improved the blood flow in both the common carotid artery and the facial nerve tissues. In this project, we investigated the combined effects of electrical stimulation and chemical blockage of cervical sympathetic trunks on microcirculation in the facial nerve. With the electrical stimulation of cervicothoracic ganglion, the blood flow in both the common carotid artery and
… More
facial nerve tissue decreased significantly. Both the common carotid arterial blood flow and facial nervous tissue blood flow returned to the baseline value immediately following the injection of mepivacaine to that ganglion. From these result, the hypertonicity of cervical sympathetic nervous system impairs the microcirculation of the facial nerve, and the denervation of such nervous system improves the circulation even if under the stimulus condition of sympathetic activity. On the basis of these findings, clinical chemical blockage of cervical sympathetic trunks could be extremely effective treatment method for Bell's palsy that might be under the sympathetic hyperactivity in head and neck. We also investigated the combined effects of hypercapnia and chemical blockage of cervical sympathetic trunks on microcirculation in the facial nerves. The blood flow in the common carotid artery did not change significantly, but remarkable decrease was observed in the tissue blood flow of facial nerve with hypercapnia. And immediately following the injection of mepivacaine to the ganglion, the common carotid arterial blood flow showed a significant increase, but the facial nerve tissue blood flow continued to decrease. With the return of ventilation to the normal condition, the blood flow in both the common carotid arterial and facial nerve tissues returned to the baseline values. High arterial CO_2 tension induced elevation of the activity level of the sympathetic nervous system through the stimulation of the hypothalamus and an adrenergic mediation. Our findings indicate that the hypercapnia, which stimulates the sympathetic nervous system, impairs the microcirculation of the facial nerve. In addition, the denervation of the cervical sympathetic nervous system does not improve the microcirculation of facial nerves when the activity of the sympathetic nervous system is centrally stimulated. The pharmacotherapeutic application of prostaglandin E1 (PGE1) can be used to increase blood flow volume in the common carotid artery. We also examined the effects of PGE1 on the blood flow volume in facial nervous tissue. The blood flow volume of the common carotid artery was increased and sustained by the application of PGE1, but The blood flow volume in the facial nervous tissue increased slightly for a short time only. A large intravenous dosage of PGE1 was required to temporarily increase the blood flow volume in facial tissue. Less
|
