Nasal cycle during sleep

Background and Objectives: The phenomena of periodic cycles of vascular engorgement on the nasal cavity mucosa that alternate between right and left sides are termed the “nasal cycle(NC).” Purpose of this study is to clarify the mechanism of nasal cycle during sleep using Polysomnography(PSG). Study design: Case series Methods: We utilized PSG and portable rhinoflowmeter (Rhinocycle, Rhinometrics, Lynge, Denmark), measuring airflow independently through each nostril during sleep on 29 healthy subjects. Results: 1, NC was found in 24 of 29 patients during PSG. 2, In 5 of 29 cases, NC with the postural change was found. 3, In 21 of 29 NC was found NC during REM sleep, 7/29 during light sleep and 1/29 during wake, however no case in slow wave sleep. 4, The NC tended to be found in REM sleep for the sleep latter half, and, furthermore, in REM sleep which duration showed longest. Conclusions: We speculated that the NC was associated with a function of the REM sleep. Further study needed to clarify the relationship between nasal cycle and brain function during sleep.