Measuring and Characterizing the Human Nasal Cycle

Abstract

Nasal airflow is greater in one nostril than in the other because of transient asymmetric nasal passage obstruction by erectile tissue. The extent of obstruction alternates across nostrils with periodicity referred to as the nasal cycle. The nasal cycle is related to autonomic arousal and is indicative of asymmetry in brain function. Moreover, alterations in nasal cycle periodicity have been linked to various diseases. There is therefore need for a tool allowing continuous accurate measurement and recording of airflow in each nostril separately. Here we provide detailed instructions for constructing such a tool at minimal cost and effort. We demonstrate application of the tool in 33 right-handed healthy subjects, and derive several statistical measures for nasal cycle characterization. Using these measures applied to 24-hour recordings we observed that: 1: subjects spent slightly longer in left over right nostril dominance (left = 2.63 ± 0.89 hours, right = 2.17 ± 0.89 hours, t(32) = 2.07, p < 0.05), 2: cycle duration was shorter in wake than in sleep (wake = 2.02 ± 1.7 hours, sleep = 4.5 ± 1.7 hours, (t(30) = 5.73, p < 0.0001). 3: slower breathing was associated with a more powerful cycle (the extent of difference across nostrils) (r = 0.4, p < 0.0001), and 4: the cycle was influenced by body posture such that lying on one side was associated with greater flow in the contralateral nostril (p < 0.002). Finally, we provide evidence for an airflow cycle in each nostril alone. These results provide characterization of an easily obtained measure that may have diagnostic implications for neurological disease and cognitive state.

Sleep architecture, insulin resistance and the nasal cycle: Implications for positive airway pressure therapy

“…The nasal cycle is a normal ultradian physiological phenomenon that manifests in all mammals, 52 where each nasal airway takes turns at conducting a greater apportionment of tidal airflow. The status of airflow dominance between the right and left nasal airways is correlated with sympathetic and parasympathetic dominant states, respectively, as regulated by the ANS, 53,54 the lateralised ultradian rhythm of alternating cerebral hemispheric dominance 55,56 and is tightly coupled to sleep staging 44,46,53,55,57,58 and sleep position.…”

The Rationale behind a Continous Nasal Positive Airway Pressure Machine That Approximates the Nasal Cycle during Sleep

“…Normally, the airflow and resistance in each nasal airway alternates between a patent and partially congested state for periods ranging from 25 minutes to greater than 4 hours, with a mean of 2.5 hours [3][4][5]. Some evidence suggests that the nasal cycle is longer during sleep compared to the waking state [3,5,6]. During sleep, changes in the nasal cycle often coincide with postural changes and may occur more often in transitions to REM sleep [5][6][7].…”

Effect of breathing practices on visual and auditory reaction time of adolescent population in Madurai, India -A comparison of right and left nostril breathing

“…At rest, in a normal individual uninostril dominance is seen, characterized by alternating patency of right and left nostrils in a 24 hour cycle. 1 Alterations in nasal cycle periodicity have been linked to various diseases. It has been reported that regular practice of breathing exercises are known to alter autonomic function and that Right Nostril Breathing (RNB) technique stimulates sympathetic activity by activating left cerebral hemisphere and Left Nostril Breathing (LNB) stimulates parasympathetic activity by activating right cerebral hemisphere.…”