Olfaction is a sense involved in a complex set of tasks, influencing eating behavior, increasing awareness of environmental hazards and affecting social communication. Surprisingly, smell disorders are very frequent, especially in the elderly population. Several recent studies conducted mostly in older subjects have demonstrated a strong association between olfactory impairment and overall mortality risk, with anosmia being even more predictive of 5 years mortality risk than cardiovascular disease. Presently, the underlying pathophysiology linking olfactory impairment to mortality remains unknown and only putative mechanisms are suggested. This review aims to examine the link between olfactory impairment and mortality and to discuss existing ideas on underlying existing mechanisms including, (1) the effect of olfactory loss on nutrition, life-threatening situations and social interactions, (2) associated neurodegenerative diseases, (3) accelerated brain aging, and (4) reflection of general health status being reflected in olfactory function.
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http://dx.doi.org/10.3389/fnins.2020.00140 | DOI Listing |
Acad Radiol
January 2025
Department of Otolaryngology and Head and Neck Surgery, School of Medicine, Otorhinolaryngology Research Center, Guilan University of Medical Sciences, Rasht, Iran (M.H.D., S.N.). Electronic address:
Background: While many COVID-19-induced anosmia patients recover their sense of smell within a few months, a substantial number of them continue to experience olfactory impairment. In our primary study, the metabolic patterns in orbitofrontal cortex (OFC) were observed to exhibit more alterations than other regions. Hence, this study specifically probes into alterations within OFC region in subjects with persistent COVID-19-induced anosmia.
View Article and Find Full Text PDFJ Physiol Sci
January 2025
Department of Autonomic Neuroscience, Tokyo Metropolitan Institute for Geriatrics and Gerontology, 35-2 Sakaecho, Itabashi-ku, 173-0015, Tokyo, Japan.
The olfactory bulb receives cholinergic basal forebrain inputs as does the neocortex. With a focus on nicotinic acetylcholine receptors (nAChRs), this review article provides an overview and discussion of the following findings: (1) the nAChRs-mediated regulation of regional blood flow in the neocortex and olfactory bulb, (2) the nAChR subtypes that mediate their responses, and (3) their activity in old rats. The activation of the α4β2-like subtype of nAChRs produces vasodilation in the neocortex, and potentiates olfactory bulb vasodilation induced by olfactory stimulation.
View Article and Find Full Text PDFZhonghua Er Bi Yan Hou Tou Jing Wai Ke Za Zhi
January 2025
Department of Otolaryngology, Eye & ENT Hospital, Fudan University, Shanghai200031, China.
To explore the differences in quality of life among patients with olfaction disorders (OD) due to various etiologies and to identify factors influencing olfactory-related quality of life. This cross-sectional study enrolled patients with OD who visited the Department of Otolaryngology at Fudan University Eye, Ear, Nose, and Throat Hospital between February and June 2024. Psychophysical olfactory test was performed using the Chinese Smell Identification Test (CSIT), which was based on the Chinese population, with the TDI score used as the total score for threshold (T), discrimination (D), and identification (I) tests.
View Article and Find Full Text PDFFront Allergy
January 2025
Unit of Otorhinolaryngology-Head and Neck Department, ASST Sette Laghi, Varese and UPLOAD (Upper and Lower Airways Diseases) Research Centre, University of Insubria, Varese, Italy.
Background: Chronic rhinosinusitis with nasal polyps (CRSwNP) is an inflammatory condition characterized by persistent nasal obstruction, discharge, facial pressure, and olfactory dysfunction. CRSwNP significantly impairs quality of life (QoL), with olfactory loss being a particularly distressing symptom that affects food enjoyment, personal safety, and social interactions.
Methods: This study investigated the experiences of Italian patients with CRSwNP.
Front Neurosci
January 2025
Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria.
Neurodegenerative diseases represent a group of disorders characterized by progressive degeneration of neurons in the central nervous system, leading to a range of cognitive, motor, and sensory impairments. In recent years, there has been growing interest in the association between neurodegenerative diseases and olfactory dysfunction (OD). Characterized by a decline in the ability to detect or identify odors, OD has been observed in various conditions, including Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and Amyotrophic Lateral Sclerosis (ALS).
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