Comparison of trigeminal lateralization with differing stimulants

Trigeminal-specific stimulants have been shown to activate different receptors preferentially and this likely accounts for variation in sensory perception.It is unclear whether trigeminal sensitivity is similar across different transient receptor potential(TRP)receptors or if dysfunction of different receptors results in differing patient symptoms.Therefore,a prospective cohort study was conducted,consisting of trigeminal lateralization testing with three different stimulants(eucalyptol,isothiocyanate,acetic acid),olfaction testing with Sniffin'Sticks,and measurement of various patient‐reported outcome measures(PROMs).A total of 50 participants were enrolled across the olfactory spectrum.Mean TDI score was 27.1±8.3(range 7.0–39.5)with 38%normosmic and 62%dysosmic.Mean trigeminal lateralization scores out of 20 in the overall cohort were 16.18(2.78)for eucalyptol,14.94(3.49)for mustard oil,and 15.28(3.68)for vinegar.Eucalyptol showed a significant correlation with threshold scores of Sniffin'Sticks.A significant correlation was found between acetic acid and various PROMs.None of the lateralization scores of the trigeminal stimulants correlated to each other significantly and there was no correlation to age.The lack of correlation suggests that the measured sensitivity of one type of TRP receptor may not translate to similar sensitivity of the other receptors.Additional investigations with TRPV1 and TRPA1 agonists are needed to corroborate our findings.

Utilization of RNA sequencing to investigate olfactory dysfunction in chronic rhinosinusitis without nasal polyps:A pilot study

Objectives:Prior research on olfactory dysfunction in chronic rhinosinusitis(CRS)has focused on patients with polyps and suggests that direct inflammation of the olfactory cleft mucosa plays a contributory role.The purpose of this study was to evaluate gene expression in superior turbinate mucosal specimens,comparing normosmic and dysosmic CRS patients without polyps(CRSsNP).Methods:Tissue samples were obtained from the superior turbinates of patients with CRSsNP at the time of endoscopic sinus surgery.Samples subsequently underwent RNA sequencing and functional analysis to investigate biological pathways associated with differentially expressed genes between dysosmic(n=7)and normosmic(n=4)patients.Results:Differential gene expression analysis comparing dysosmic and normosmic CRSsNP patients showed upregulation of 563 genes and downregulation of 327 genes.Using stringent criteria for multiple comparisons,one upregulated gene(Immediate Early Response 3[IER3])had an false discovery rate(FDR)correction adjustedP value considered statistically significant(P<0.001,fold change 2.69).Reactome functional analysis revealed eight biological pathways significantly different between dysosmic and normosmic patients(P<0.05,FDR correction)including IL-4 and IL-13 signaling,IL-10 signaling,and rhodopsin-like receptors.Conclusions:RNA sequencing of the superior turbinates in patients with CRSsNP can provide valuable information regarding biological pathways and genes involved in olfactory dysfunction.This study supports literature suggesting that Type 2 inflammation may play a role in olfactory dysfunction in at least some patients with CRSsNP.This study also prompts questions regarding the role of IL-10,rhodopsin-like receptors,andIER3 in the pathogenesis of olfactory dysfunction.