title: Lateralized differences in olfactory function and olfactory bulb volume relate to nasal septum deviation.
abstract: One of the most common reasons for partial nasal obstruction is nasal septal deviation (NSD). The effect of a partial lateralized nasal obstruction on olfactory bulb (OB) volume remains unclear. Thus, the aim of this study was to investigate the side differences in olfactory function and OB in patients with serious NSD. Sixty-five volunteers were included: 22 patients with serious right NSD and 43 patients with left NSD. The patients' mean age was 22 years. All participants received volumetric magnetic resonance imaging scans of the entire brain and detailed lateralized olfactory tests. The majority of the patients exhibited an overall decreased olfactory function (as judged for the better nostril: functional anosmia in 3%, hyposmia in 72%, normosmia in 25%), which seems to be mostly due to the overall severe changes in nasal anatomy. As expected, olfactory function was significantly lower at the narrower side as indicated for odor thresholds, odor discrimination, and odor identification (P ≤ 0.005). When correlating relative scores and volumes (wider minus narrower side), a significantly positive correlation between the relative measures emerged for OB volume and odor identification, odor discrimination, and odor thresholds. Our study clearly highlights that septal deviation results in decreased olfactory function at the narrower side.
authors.affiliation: From the *Division of Otorhinolaryngology, Istanbul Surgery Hospital; and Departments of †Otorhinolaryngology, ‡Neurology, and §Radiology, Gülhane Military Medical Academy (GATA) Haydarpaşa Training Hospital, Istanbul; and ∥Department of Otorhinolaryngology, Amasya University Training and Research Hospital, Amasya, Turkey; and #Smell & Taste Clinic, Department of Otorhinolaryngology, Technical University of Dresden, Germany.
authors.forename: Aytug
authors.initials: A
authors.lastname: Altundag
authors.forename: Murat
authors.initials: M
authors.lastname: Salihoglu
authors.forename: Hakan
authors.initials: H
authors.lastname: Tekeli
authors.forename: Muzaffer
authors.initials: M
authors.lastname: Saglam
authors.forename: Melih
authors.initials: M
authors.lastname: Cayonu
authors.forename: Thomas
authors.initials: T
authors.lastname: Hummel
mesh_terms: D001921:Brain / Q000473:pathology; D003430:Cross-Sectional Studies; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009296:Nasal Cavity / Q000473:pathology; D015508:Nasal Obstruction / Q000209:etiology / Q000473:pathology; D009300:Nasal Septum / Q000002:abnormalities* / Q000473:pathology; D009812:Odorants; D000857:Olfaction Disorders / Q000175:diagnosis / Q000473:pathology; D009830:Olfactory Bulb / Q000473:pathology*; D009929:Organ Size; D012684:Sensory Thresholds / Q000502:physiology; D012903:Smell / Q000502:physiology*; D055815:Young Adult