The importance of olfactory and trigeminal event-related potentials (OERPs/TERPs) in the assessment of olfactory function in subjects with chronic rhinosinusitis with nasal polyposis

Abstract

Objectives: Smell impairment (SI) is a well-known symptom of chronic rhinosinusitis with nasal polyps (CRSwNP). The aim of study was to analyze olfactory and trigeminal event-related potentials (OERPs/TERPs) and psychophysical smell tests in subjects with CRSwNP, and its potential role in clinical practice. Methods: Prospective study included 57 subjects. Two investigated groups with CRSwNP and one control group. Group I (n = 20) contained subjects without CRSwNP before septoplasty. Group II (n = 18) contained subjects with CRSwNP without therapy. Group III (n = 19) contained subjects with CRSwNP after intranasal corticosteroid therapy. Sniffin stick identification smell test and OERPs/TERPs were performed in all subjects. Results: According to the psychophysical smell test, SI was detected in 65% of subjects with CRSwNP. In the control Group I (without CRSwNP), the absence of OERPs was 5.0%, whilethe mean absence rate in Groups II, III (with CRSwNP) was 8.1%. The highest percentage of absence of OERPs was registered in Group II (11.1%). Absence of TERPs was detected in an average of 21.6% of CRSwNP subjects. Group III showed the highest percentage of absence of TERPs (32%). In the control Group I, TERPs were absent in 0% of subjects. Conclusion: CRSwNP significantly impairs olfactory function compared to patients without CRSwNP, Absence of TERPs was detected in an average of 21.6% of CRSwNP subjects versus healthy controls (0%). Presence of TERPs appears to be a predictor of preservation of olfactory function.