In this video the ENS victim advocate Barbara Schmidt provides an overview of Empty Nose Syndrome, which is an iatrogenic disorder resulting from sinus and nasal-related surgeries in which the turbinates are affected.
Mechanism of ENS
The Empty Nose Syndrome can be caused by a partial or a complete cut of the inferior or middle turbinates. It can even be caused by a burn of the mucosa. The cut causes a loss of volume, that's to say an increase in emptiness and a reduction in the mucosa surface. The burn affects negatively the health of the mucosa. All of this has many effects:
The increase in emptiness causes:
A modification in the distribution of the airflow, most of the airflow is redirected in the middle meatus in case of an inferior turbinectomy [1].
An increase in the cross-sectional area which reduces the velocity of the airflow and affects negatively the Wall Shear Stress. Less WSS means less evaporation of the mucus due to the airflow passage which leads to less cooling effect of the mucosa. Indeed the change of the mucus from the liquid state to the gaseous state leads to energy consumption which cools the mucosa. And it is this cooling that detects the TRPM8 receptors and gives us the feeling of the airflow [2]. The increase in the cross-sectional area also reduces nasal resistance.
The reduction in the mucosa surface causes:
A reduction in the numbers of TRPM8 receptors simply because the receptors are in the mucosa and the fewer mucosa there are, the fewer receptors there are.
A reduction of the production of mucus because it is the same thing, the glands that produce mucus are found in the mucosa [3].
A reduction in the number of blood vessels which can decrease the temperature of the mucosa. Simply because the mucosa is kept at the right temperature thanks to the blood flow.
The cut of turbinates disturbs the nasal cycle because a large part of the turbinates has disappeared. The nasal cycle is the phenomenon that consists of vasodilation of the turbinates on one side and then the other over a cycle of a few hours. However, it seems that the utility of the nasal cycle is still unknown [4]. But the phenomenon of vasodilatation/vasoconstriction has another very important role which is to adapt the cross-sectional area according to physical activity. Indeed during physical activity the airflow increases, in response to this, the turbinates decrease in volume via the phenomenon of vasoconstriction [5].