Pathophysiological siignificance of elevated sympathetic nerve activity during sleep in chronic sleep disorders

点击翻译按钮获取中文摘要

Sleep disorders are abnormal states with very high prevalence. They are induced by multiple factors, i.e. mental stress or depression. We investigated the pathophysiological mechanisms underlying insomniacs with sleep disordered breathing including obstructive sleep apnea syndrome (OSAS) and upper airway resistance syndrome (UARS), and those with gastroesophageal reflux (GER). Methodologically, over-night polysomnography (PSG) ware performed with continuous measure of digital plethysmography (DPG) to study sympathetic nerve activity through blood flow volume change during sleep. In the patinets with OSAS, digital blood flow markedly decreased just after the electroencepharographical arousal following the resumption of respiration, and the second blood flow decrement, which did not often occurred 5-10 seconds after the first episode. As the second episode was not observed in the patients with UARS, its pathogenesis may be probably related to hypoxemia. On the other hand, sleep disturbance related to GER was investigated to perform our original questionaires for the workers and retired rugger men. The complaint of heartburn was found in about 30% of the subjects and was clarified to be an independent factor other than sleep apnea to induce sleep problems. Electrogastrography before and after CPAP treatment revealed that CPAP tended to reduce bradygastria and tachygastria in a few patients with OSAS patients. Future investigation about these findings must be needed.