Abstract:
Rationale: Apneic individuals have reduced airway caliber during sleep. The biomechanical changes in upper airway anatomy contributing to this airway narrowing are largely unknown. Objectives: We sought to investigate the state-dependent (wake vs. sleep) biomechanical behavior of the upper airway soft-tissue and craniofacial structures. Methods: Upper airway magnetic resonance imaging was performed in 15 sleep-deprived control subjects (apnea-hypopnea index, <5; 0.3 ± 0.5 events per hour) and 12 sleep-deprived apneic subjects (apnea-hypopnea index, ⩾5; 35.2 ± 18.1 events per hour) during wake and sleep and analyzed for airway measures and soft-tissue/mandibular movement. Results: In the retropalatal region, control subjects showed sleep-dependent reductions (P ⩽ 0.037) in average cross-sectional airway area (CSA), minimum CSA, and anteroposterior and lateral dimensions. Apneic subjects showed sleep-dependent reductions (P ⩽ 0.002) in average CSA, minimum CSA, and anteroposterior and lateral dimensions. In the retroglossal region, control subjects had no sleep-dependent airway reductions. However, apneic subjects had sleep-dependent reductions in minimal CSA (P = 0.001) and lateral dimensions (P = 0.014). Control subjects only showed sleep-dependent posterior movement of the anterior-inferior tongue octant (P = 0.039), whereas apneic subjects showed posterior movement of the soft palate (P = 0.006) and all tongue octants (P ⩽ 0.012). Sleep-dependent medial movement of the lateral walls was seen at the retropalatal minimum level (P = 0.013) in control subjects and at the retropalatal and retroglossal minimum levels (P ⩽ 0.017) in apneic subjects. There was posterior movement of the mandible in apneic subjects (P ⩽ 0.017). Conclusions: During sleep, control and apneic subjects showed reductions in retropalatal airway caliber, but only the apneic subjects showed retroglossal airway narrowing. Reductions in anteroposterior and lateral airway dimensions were primarily due to posterior soft palate, tongue and mandibular movement and to medial lateral wall movement. These data provide important initial insights into obstructive sleep apnea pathogenesis.
摘要:
理由:呼吸暂停患者在睡眠期间气道口径降低。导致这种气道狭窄的上气道解剖结构的生物力学变化在很大程度上是未知的。目标:我们试图调查状态依赖性(唤醒与睡眠)上气道软组织和颅面结构的生物力学行为。方法:对15例睡眠剥夺的对照组进行了上气道磁共振成像(呼吸暂停低通气指数,<5;每小时0.3±0.5个事件)和12名睡眠不足的呼吸暂停受试者(呼吸暂停低通气指数,5;35.2±18.1事件每小时)在唤醒和睡眠和分析气道措施和软组织/下颌运动。结果:在腭后区域,对照组的平均气道横截面积(CSA)表现出睡眠依赖性减少(P0.037),最低CSA,前后尺寸和外侧尺寸。呼吸暂停受试者在平均CSA中表现出睡眠依赖性减少(P﹤0.002),最低CSA,前后尺寸和外侧尺寸。在舌后区,对照组没有睡眠依赖性气道减少.然而,呼吸暂停患者在最小CSA(P=0.001)和横向尺寸(P=0.014)方面具有睡眠依赖性降低。对照组仅显示前下舌体的睡眠依赖性后运动(P=0.039),而呼吸暂停的受试者显示软腭(P=0.006)和所有舌八分位(P﹤0.012)的向后运动。在对照组受试者中,在pal后最低水平(P=0.013)以及在呼吸暂停受试者中,在pal后和舌后最低水平(P﹤0.017)观察到外侧壁的睡眠依赖性内侧运动。在呼吸暂停的受试者中,下颌骨有向后运动(P﹤0.017)。结论:在睡眠期间,对照组和呼吸暂停患者显示腭后气道口径减少,但只有呼吸暂停患者表现出舌后气道狭窄。前后气道和外侧气道尺寸的减少主要是由于后软腭,舌头和下颌运动以及内侧外侧壁运动。这些数据为阻塞性睡眠呼吸暂停的发病机制提供了重要的初步见解。