Brain volume changes in hyposmic patients before and after olfactory training. (14th December 2017)

• Record Type: Journal Article
• Authors: Gellrich, Janine; Han, Pengfei; Manesse, Cedric; Betz, Amelie; Junghanns, Anne; Raue, Claudia; Schriever, Valentin A.; Hummel, Thomas
• Is Part Of: Laryngoscope. Volume 128:Number 7(2018)
• Page Start: 1531
• Page End: 1536
• Publication Date: 2017-12-14
• Subjects: Upper respiratory tract infection -- olfactory disorders -- gray matter -- voxel‐based morphometry -- olfactory bulb -- olfactory training; Otolaryngology -- Periodicals; 617.51005
• DOI: 10.1002/lary.27045
• Languages: English
• ISSNs: 0023-852X

Abstract

Abstract : Objectives/Hypothesis: Olfactory dysfunction is thought to be associated with reduced gray matter (GM) volume in olfactory‐related brain areas. The aim of this study was to determine GM structural changes within olfactory‐related regions of the brain in patients with smell loss due to upper respiratory tract infection (URTI) before and after olfactory rehabilitation. Study Design: Prospective intervention case‐control study. Methods: Magnetic resonance imaging structural brain images were collected from 30 patients with smell loss due to URTI and 31 controls. Patients exposed themselves to odors (olfactory training [OT]) over 12 weeks and then were rescanned. Olfactory testing was performed using the validated Sniffin' Sticks test. GM was investigated with voxel‐based morphometry. Results: GM volumes were found to be reduced in the limbic system and thalamus among pretraining patients compared to controls; in patients, OT was associated with a significant increase of GM volume in these two regions. The GM volume within other olfactory‐related regions was not different between patients and controls. In addition, no relevant difference between the GM volume pre‐ and post‐OT was observed in primary olfactory‐related regions. Conclusions: OT was associated with an increase in GM volume of the hippocampus and the thalamus, possibly pointing toward a strategy for more effective exploitation of olfactory signals based on a higher degree of attention toward odors and association of memories with olfactory input. Level of Evidence: 3b. Laryngoscope, 128:1531–1536, 2018