Saturday, December 3, 2016

Nasal Cycle, Turbinates & Sleep

"The nasal cycle is the often unnoticed[1][2] alternating partial congestion and decongestion of the nasal cavities in humans and other animals. It is a physiological congestion of the nasal concha, also called the nasal turbinate, due to selective activation of one half of the autonomic nervous system by the hypothalamus. It should not be confused with pathological nasal congestion. The nasal cycle was studied and discussed in the ancient yoga literature.[3] In the modern western literature, it was first described by the German physician Richard Kayser in 1895.

 In 1927 Heetderks[5] spoke about the alternating turgescence of the inferior turbinates in 80% of a normal population. The cycle is the result of alternating congestion and decongestion of the nasal conchae or turbinates, predominantly the inferior turbinates, which are by far the largest of the turbinates in each nasal fossa. Turbinates consist of bony projections covered by erectile tissue, much like the tissues of the penis and clitoris. The turbinates in one fossa filled up with blood while the opposite turbinates decongested by shunting blood away. This cycle, which is controlled by the autonomic nervous system as described above, had a mean duration of two and a half hours. He further observed and documented that the turbinates in the dependent nasal fossa filled when the patient was in the lateral decubitus (lying down on your side) position. Some[who?] postulate that this alternating positional obstruction has the purpose of causing a person to turn from one side to the other while sleeping. Others note that the asymmetric airflow may have some benefit to overall olfactory sensitivity.[6] The nasal cycle is an alternating one, with the total resistance in the nose remaining constant. In patients with a fixed septal deviation and intermittent nasal obstruction, the interplay of the nasal cycle becomes evident; the sensation of obstruction frequently mirrors the congestion phase.[6] It is possible that the nasal cycle may exacerbate the nasal congestion caused by the common cold, as the lack of motility of the cilia in one half of the nose may lead to an uncomfortable sensation of not being able to shift mucus by blowing the nose."

From my experience as a side sleeper indications are that when you first turn on to one side (lets say the left side for example) I notice my right congested side nostril (side furthest from my pillow) starting to open up somewhat or decongest. Since I practically have very little remaining of my Left Inferior Turbinate this is harder for me to gauge when lying on my right side but I still to smaller degree feel this same phenomena. On my right side I can somewhat notice my right nasal cavity (side nearest my pillow) start to swell or close up to some degree. I have my full middle turbinates so perhaps that's why I can still to very small degree detect changes in nasal cycle even with my left nostril when lying on my right side. However this sensation may also be accentuated & related to other reasons such as draining of sinuses &/or squishing of side cheek & nostril up against the pillow.  According to studies "In healthy individuals, the lateral decubitus (lying down) increases congestion in the ipsilateral (same side) nasal cavity and reduces airflow resistance in the contralateral (opposite side) nasal cavity. This does not occur due to a hydrostatic effect, but rather as a reflex response caused by asymmetric pressure on the body [11, 12]. Studies also show that nasal cycle duration during sleep is longer then in wakefulness.  Another interesting conclusion from one study states, "changes in laterality of nasal cycle frequently coincide with switches in posture, tend to occur in REM sleep, never occur in slow-wave sleep, and may be absent in subjects with severe nasal septal deviations".  Atanasov and coworkers [6] showed that the switch from left to right nostril’s domination airflow (and reverse) occurs only during REM phases of the night sleep. Ten years later Kimuraet al.[7] received similar result".  From my personal experience I do not have to even be asleep, never mind being in a REM sleep phase to affect change in my nasal cycle.  At times I have noticed  approx. within 5 to 7 minutes of turning on my left side my right blocked up nasal cavity open up.  I would be interested in hearing from you the readers of this blog about your personal experience on this subject. So feel free to leave a comment.

My main concern would be how one's sleep could be negatively impacted if they have had major removal of their middle &/or inferior turbinates from one nostril or worse both nostrils. I would postulate that losing your 'normal' cycling of the nasal cycle could potentially affect not just regular sleep patterns but also REM sleep (associated with deep dream sleep). However if it's true that 20% of the population does not experience this nasal cycle it would be interesting to compare their sleeping patterns to the 80% of those that do experience the nasal cycle & to those who have had major removal of both middle/inferior turbinates as i describe above. As far as I know there hasn't been any related studies to comment on this further. As far as how my sleeping pattern goes, it has been negatively impacted from the rhinoplasty's I've had. This is not just due to near complete removal of  my left inferior turbinate but also due to hypertrophy of  remaining right  I.T., nerve pain, & nasal valve collapse. I noticed particularly after my last revision rhinoplasty where my Left inferior turbinate was practically fully removed & Right I.T. further reduced that when I awoke it was much more difficult for me to remember my dreams then prior to the surgery.  I notice that I feel more of an instant awakening now then prior which was more gradual.  However I still do get REM sleep & force myself to try & recall my dreams upon awakening.

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