| Project/Area Number |
12671651
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Otorhinolaryngology
|
|---|
| Research Institution | CHIBA UNIVERSITY |
|---|
Principal Investigator |
SHIBA Keisuke Chiba University, Chiba University Hospital, Assistant, 医学部・附属病院, 助手 (40291299)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
NAKAZAWA Ken Chiba University, Graduated School of Medicine, Lecturer, 大学院・医学研究院, 講師 (10312943)
林 文明 千葉大学, 医学部, 助教授 (80173029)
|
|---|
| Project Period (FY) |
2000 – 2001
|
| Project Status |
Completed (Fiscal Year 2001)
|
| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2001: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2000: ¥2,700,000 (Direct Cost: ¥2,700,000)
|
|---|
| Keywords | larynx / thyroarytenoid muscle / multiple system atrophy / cat / laryngeal obstruction / 甲状披裂筋 / 呼吸中枢 |
|---|
| Research Abstract |
1. We determined the breathing pattern and firing timing of TA muscle activation in ten patients with multiple system atrophy (MSA) anaesthetized with propofol and breathing through the laryngeal mask airway, while the behavior of the laryngeal aperture was being observed endoscopically. Significant laryngeal narrowing was observed leading to an increase in laryngeal resistance. Application of continuous positive airway pressure suppressed the adductor activation. The results indicate that adductor contraction during inspiration narrows the larynx leading to development of inspiratory flow limitation accompanied by stridor in patients with MSA.
2. In five patients with vocal cord abduction impairment, we investigated the role of the vocal cord adductor in generating dyspnea in laryngeal obstruction by recording its electromyographic activity and by observing vocal cord movement endoscopically under propofol anesthesia. The adductor was activated during inspiration and the glottis was cl
… More
osed with laryngeal stridor. Because this adductor inspiratory activity was abolished by opening tracheostoma in tracheostomized patients, it is strongly suspected that this inspiratory adductor activity is induced by the airway reflex.
3. We hypothesized that an airway reflex attributable to insufficient opening of the glottis during inspiration causes this adductor inspiratory activity. To identify such airway reflex, we recorded the adductor electromyogram in the cat whose vocal cords were mechanically adducted by stitching both vocal processes together under propofol anesthesia. In these cats, the adductor was activated during inspiration with powerful negative pressure in the trachea. The adductor was activated by negative pressure in the subglottic space, but scarcely activated by in the lower airway. In addition, the adductor inspiratory activity in glottis-closed cats was usually abolished by laryngeal deafferentation. We conclude that the airway reflex triggered by subglottic negative pressure attributable to glottal narrowing during inspiration causes the adductor inspiratory activity similar to that in MSA patients. Less
|
