Trigeminal impairment in treatment-refractory chronic nasal obstruction

Patients with anatomically unexplained, chronic nasal obstruction (CNO) that is refractory to medical treatment pose a challenge for clinicians. A surgical solution, addressing mechanical obstacles, is unsuited for these patients. CNO may result from disrupted airflow perception due to activation of the intranasal trigeminal system; therefore, aim of this study is to evaluate if intranasal trigeminal function of these CNO patients is decreased.

In this retrospective cross-sectional study, we compared 143 CNO patients and 58 healthy volunteers, between 18 to 80 years old. We assessed nasal patency by means of rhinomanometry (RM) and measured susceptibility of intranasal trigeminal system by the trigeminal lateralization task (TLT).

TLT scores were significantly lower in CNO patients compared to controls (p less than 0.001), but RM scores were not different between groups. Accordingly, TLT allowed to identify CNO patients with an accuracy of the area under the curve (AUC) of 0.78, while the value for RM was at chance (AUC=0.47). CNO patients showed normal reaction to vasoconstrictive agents with significantly lower RM values after Xylomethazoline application.

Results suggest that reported nasal obstruction in CNO patients without any obvious anatomical obstacle and resistant to medical treatment may be linked to decreased perception of nasal airflow rather than physical obstruction. In this sub-set of CNO patients, trigeminal testing more adequately reflects the reported obstruction than nasal resistance assessment does. In future studies, the relation of the trigeminal status and the subjective sensation of nasal obstruction needs to be addressed with validated patient rated outcome measures (PROMs).