title: Gray matter volume reduction of olfactory cortices in patients with idiopathic olfactory loss.
abstract: Idiopathic olfactory loss (IOL) is a common olfactory disorder. Little is known about the pathophysiology of this disease. Previous studies demonstrated decreased olfactory bulb (OB) volume in IOL patients when compared with controls. The aim of our study was to investigate structural brain alterations in areas beyond the OB. We acquired T1-weighted magnetic resonance images from 16 patients with IOL and from 16 age- and sex-matched controls on a 3T scanner. Voxel-based morphometry (VBM) was performed using VBM8 toolbox and SPM8 in a Matlab environment. Psychophysical testing confirmed that patients had higher scores for Toyota and Takagi olfactometer and lower scores for Sniffin' Sticks olfactory test than controls (t = 46.9, P < 0.001 and t = 21.4, P < 0.001, respectively), consistent with olfactory dysfunction. There was a significant negative correlation between the 2 olfactory tests (r = -0.6, P = 0.01). In a volume of interest analysis including primary and secondary olfactory areas, we found patients with IOL to exhibit gray matter volume loss in the orbitofrontal cortex, anterior cingulate cortex, insular cortex, parahippocampal cortex, and the piriform cortex. The present study indicates that changes in the central brain structures proximal to the OB occur in IOL. Further investigations of this phenomenon may be helpful to elucidate the etiology of IOL.
authors.affiliation: Department of Otolaryngology Head and Neck Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing 100029, China.
authors.forename: Linyin
authors.initials: L
authors.lastname: Yao
authors.affiliation: Section of Otolaryngology-Head and Neck Surgery, Department of Surgery, The University of Chicago, Chicago, IL 60637, USA.
authors.forename: Jayant Marian
authors.initials: JM
authors.lastname: Pinto
authors.affiliation: Department of Radiology, The Affiliated Children's Hospital, Capital Institute of Pediatrics, Beijing 100020, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Yi
authors.affiliation: Department of Otolaryngology Head and Neck Surgery, Beijing Chaoyang Hospital, Capital Medical University, Beijing 100020, China and.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Radiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing 100020, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Peng
authors.affiliation: Department of Otolaryngology Head and Neck Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing 100029, China, wei.yongxiang@hotmail.com.
authors.forename: Yongxiang
authors.initials: Y
authors.lastname: Wei
mesh_terms: D000328:Adult; D005260:Female; D066128:Gray Matter / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D000857:Olfaction Disorders / Q000473:pathology* / Q000503:physiopathology; D066194:Olfactory Cortex / Q000473:pathology* / Q000503:physiopathology; D009929:Organ Size
keywords: gray matter volume; human; idiopathic; magnetic resonance imaging; olfactory loss; voxel-based morphometry