Olfactory Cleft Width and Volume: Possible Risk Factors for Postinfectious Olfactory Dysfunction

Abstract

Objectives/Hypothesis Upper respiratory tract infections are a common cause of temporary and permanent olfactory dysfunction in the general population. Postviral or postinfectious olfactory loss (PIOL) develops only in rare cases. The aim of this study was to investigate the anatomical features of olfactory cleft (OC) in patients with PIOL to shed light on possible predisposing factors for PIOL. Study Design Retrospective study. Methods We retrospectively evaluated paranasal sinus computed tomography (CT) scan results of patients diagnosed with PIOL. A control group consisted of normosmic individuals who underwent paranasal sinus CT scans before septoplasty surgery. We compared the olfactory fossa depth, OC width, and volume on the CT scans of the PIOL and control groups. Results In total, 71 individuals fulfilled the study criteria (PIOL group, n = 32; control group, n = 39). There was no statistically significant difference in the olfactory fossa depth in the two groups. The OC width and volume in the PIOL group was found to be significantly increased than that in the control group (P < .001 for both). Conclusions Patients with PIOL had increased OC width and volume than the healthy controls. An extra‐wide olfactory cleft may be a predisposing factor in the pathogenesis of PIOL. Level of Evidence 4 Laryngoscope, 131:5–9, 2021

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“…Among the countless existing theories, the most notable ones include olfactory cleft syndrome and postviral anosmia syndrome. 111 The former theory advocates on mucosal obstruction at the olfactory cleft results in conduction impairment of smell, 112 while the latter proposes on a neural loss mechanism whereby direct injury to the olfactory sensory neurons preceding viral infection. 113 It is noteworthy that postviral olfactory loss (PVOL) is not a novel phenomenon.…”

Anosmia, hyposmia, and dysgeusia as indicators for positive SARS‐CoV‐2 infection

“…Endoscopy provides valuable visualization of the nasal passageway that might reveal the presence of an obstruction, mucosal inflammation, polyps, or even malignancies that may obstruct the olfactory cleft. 10,22 These practice changes place the otolaryngologist and the patient in unique predicament.…”

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“…52 Increase in olfactory cleft (OC) width and volume was noted to be a potential risk factor for PVOD. 46 Three studies demonstrated significant reduction in OB volume in patients with PVOD, 48,50,51 and that greater duration of PVOD led to greater reduction in OB volume. 48,51 Finally, one study showed that metabolic activities of higher olfactory centers were reduced following PVOD.…”