Investigation of the abnormal nasal aerodynamics and trigeminal functions among empty nose syndrome patients

• Published in: International forum of allergy & rhinology 2018-03, Vol.8 (3), p.444-452
• Main Authors: Li, Chengyu, Farag, Alexander A., Maza, Guillermo, McGhee, Sam, Ciccone, Michael A., Deshpande, Bhakthi, Pribitkin, Edmund A., Otto, Bradley A., Zhao, Kai
• Format: Article
• Language: English
• Subjects: Adult; Aged; Asphyxia; Bone; computational fluid dynamics; Computed tomography; Computer applications; empty nose syndrome; Female; Humans; Hydrodynamics; Male; Mechanical stimuli; Menthol; Middle Aged; Mucosa; nasal airflow dynamics; Nose; Nose Diseases - diagnostic imaging; Nose Diseases - physiopathology; Surveys and Questionnaires; Symptom Assessment; Syndrome; Tomography, X-Ray Computed; trigeminal function; Trigeminal Nerve - physiopathology; wall shear stress; Young Adult
• ISSN: 2042-6976; 2042-6984
• DOI: 10.1002/alr.22045

Background Abnormal nasal aerodynamics or trigeminal functions have been frequently implicated in the symptomology of empty nose syndrome (ENS), yet with limited evidence. Methods Individual computed tomography (CT)‐based computational fluid dynamics (CFD) was applied to 27 ENS patients to simulate their nasal aerodynamics and compared with 42 healthy controls. Patients’ symptoms were confirmed with Empty Nose Syndrome 6‐item Questionnaire (ENS6Q), 22‐item Sino‐Nasal Outcome Test (SNOT‐22), and Nasal Obstruction Symptom Evaluation (NOSE) scores. Nasal trigeminal sensitivity was measured with menthol lateralization detection thresholds (LDTs). Results ENS patients had significantly lower (∼25.7%) nasal resistance and higher (∼2.8 times) cross‐sectional areas compared to healthy controls (both p < 0.001). Despite inferior turbinate reductions, CFD analysis demonstrated that ENS patients had increased airflow concentrated in the middle meatus region (66.5% ± 18.3%) compared to healthy controls (49.9% ± 15.1%, p < 0.0001). Significantly less airflow (25.8% ± 17.6%) and lower peak wall shear stress (WSS) (0.58 ± 0.24 Pa) were found in the inferior meatus (vs healthy: 36.5% ± 15.9%; 1.18 ± 0.81 Pa, both p < 0.05), with the latter significantly correlated with the symptom scores of ENS6Q (r = −0.398, p = 0.003). Item‐wise, complaints of “suffocation” and “nose feels too open” were also found to be significantly correlated with peak WSS around the inferior turbinate (r = −0.295, p = 0.031; and r = −0.388, p = 0.004, respectively). These correlations were all negative, indicating that less air‐mucosal stimulations resulted in worse symptom scores. ENS patients (n = 12) also had impaired menthol LDT when compared to healthy controls (p < 0.0001). Conclusion This is the first CFD examination of nasal aerodynamics in a large cohort of ENS patients. The results indicated that a combination of loss of neural sensitivity and poorer inferior air‐mucosal stimulation may potentially lead to ENS symptomology.