xRead - Olfactory Disorders (September 2023)

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359

PATEL et al.

TABLE VII.2 (Continued) Study

Year LOE Study design

Study groups

Clinical end point

Conclusions Mucosal eosinophils ( > 5per high-power field) present in 66.7% of patients with CRSwNP Lower SIT in eosinophilic CRSwNP compared with noneosinophilic CRSwNP (19.3 ± 11.3 vs 25.1 ± 9.8; P < 0.001) No correlation between mucosal Increase in OBV following surgery correlated with odor thresholds (left side: r = 0.60, P = 0.005; right side: r = 0.49, P = 0.03), but not with odor discrimination or odor identification No change in OBV nor olfactory testing was seen among control group No difference in OBV among patients with CRSsNP vs controls OBV was inversely correlated with Lund-Mackay score ( r = – 0.52, P = 0.001), scores ≤ 12had larger OBVs compared with scores > 12) Higher Lund-Mackay score correlated with worse retronasal OF ( r = –0.040, P = 0.014) but not with orthonasal OF Better retronasal than orthonasal OF in the presence of anterior OC obstruction with CRSwNP No difference between retronasal and orthonasal smelling among controls eosinophil counts and UPSIT R scores among patients with CRSsNP

Gudziol 205

2009 4

Case series

CRSwNP (n = 19) HCs (n = 18)

Preoperative and

3-month postoperative olfactory testing (SS-TDI) and MRI volumetric measurement of OB

Rombaux 204 2008 4

Case series

CRSsNP (n = 22) HC(n = 16)

Olfactory testing: retronasal and

orthonasal (SS-TDI)

MRI volumetric

measurement of OB

Lund-Mackay score

Landis 139

2003 4

Case series

CRSwNP (n = 42) HCs (n = 56)

Olfactory testing: retronasal and

orthonasal SS-ID (10 odors)

CLC = Charcot-Leyden crystal; CRS = chronic rhinosinusitis; CRSwNP = chronic rhinosinusitis with nasal polyps; CRSsNP = chronic rhinosinusitis without nasal polyps; CT = computed tomography; HC = healthy control; IL = interleukin; LOE = level of evidence; MRI = magnetic resonance imaging; NP = nasal polyp; OB = olfactory bulb; OBV: olfactory bulb volume; OC = olfactory cleft; OF = olfactory function; SIT = Smell Identification Test; SS-ID = Sniffin’ Sticks identification only; SS-T = Sniffin’ Sticks threshold only; SS-TDI = Sniffin’ Sticks threshold, discrimination, identification combination; UPSIT R = University of Pennsylvania Smell Identification Test.

loss. 197 In this mechanism, odorants may reach the OC but inflammatory changes of the neuroepithelium disrupt transduction. In CRSsNP animal models where inflamma tory mediators such as TNF- α were directly induced in olfactory inflammation, neuronal cell death and inhibition of OE proliferation were observed. 194,195 This neuroepithe lial inflammation was temporary and resulted in reversible interference in odorant transduction. In patients with

CRSwNP, mucosal inflammation and tissue eosinophilia ( > 5 eosinophils per high-power field) have been associated with worse objective OF at baseline. 197 Following sinus surgery, improvements have been reported among patients with nasal polyposis and eosinophilia. 198–200 In the sec tion to follow on endotyping, studies have also found a correlation between olfaction and the level of inflamma tory proteins found in OC mucus, including IL-5, IL-13,