1
|
Lee S, Song Y, Hong H, Joo Y, Ha E, Shim Y, Hong SN, Kim J, Lyoo IK, Yoon S, Kim DW. Changes in Structural Covariance among Olfactory-related Brain Regions in Anosmia Patients. Exp Neurobiol 2024; 33:99-106. [PMID: 38724479 PMCID: PMC11089402 DOI: 10.5607/en24007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 04/01/2024] [Accepted: 04/09/2024] [Indexed: 05/15/2024] Open
Abstract
Anosmia, characterized by the loss of smell, is associated not only with dysfunction in the peripheral olfactory system but also with changes in several brain regions involved in olfactory processing. Specifically, the orbitofrontal cortex is recognized for its pivotal role in integrating olfactory information, engaging in bidirectional communication with the primary olfactory regions, including the olfactory cortex, amygdala, and entorhinal cortex. However, little is known about alterations in structural connections among these brain regions in patients with anosmia. In this study, high-resolution T1-weighted images were obtained from participants. Utilizing the volumes of key brain regions implicated in olfactory function, we employed a structural covariance approach to investigate brain reorganization patterns in patients with anosmia (n=22) compared to healthy individuals (n=30). Our structural covariance analysis demonstrated diminished connectivity between the amygdala and entorhinal cortex, components of the primary olfactory network, in patients with anosmia compared to healthy individuals (z=-2.22, FDR-corrected p=0.039). Conversely, connectivity between the orbitofrontal cortex-a major region in the extended olfactory network-and amygdala was found to be enhanced in the anosmia group compared to healthy individuals (z=2.32, FDR-corrected p=0.039). However, the structural connections between the orbitofrontal cortex and entorhinal cortex did not differ significantly between the groups (z=0.04, FDR-corrected p=0.968). These findings suggest a potential structural reorganization, particularly of higher-order cortical regions, possibly as a compensatory effort to interpret the limited olfactory information available in individuals with olfactory loss.
Collapse
Affiliation(s)
- Suji Lee
- College of Pharmacy, Dongduk Women’s University, Seoul 02748, Korea
| | - Yumi Song
- Ewha Brain Institute, Ewha Womans University, Seoul 03760, Korea
- Department of Brain and Cognitive Sciences, Ewha Womans University, Seoul 03760, Korea
| | - Haejin Hong
- Ewha Brain Institute, Ewha Womans University, Seoul 03760, Korea
| | - Yoonji Joo
- Ewha Brain Institute, Ewha Womans University, Seoul 03760, Korea
| | - Eunji Ha
- Ewha Brain Institute, Ewha Womans University, Seoul 03760, Korea
| | - Youngeun Shim
- Ewha Brain Institute, Ewha Womans University, Seoul 03760, Korea
- Department of Brain and Cognitive Sciences, Ewha Womans University, Seoul 03760, Korea
| | - Seung-No Hong
- Department of Otorhinolaryngology-Head & Neck Surgery, Boramae Medical Center, Seoul National University College of Medicine, Seoul 07061, Korea
| | - Jungyoon Kim
- Ewha Brain Institute, Ewha Womans University, Seoul 03760, Korea
- Department of Brain and Cognitive Sciences, Ewha Womans University, Seoul 03760, Korea
| | - In Kyoon Lyoo
- Ewha Brain Institute, Ewha Womans University, Seoul 03760, Korea
- Department of Brain and Cognitive Sciences, Ewha Womans University, Seoul 03760, Korea
- Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul 03760, Korea
| | - Sujung Yoon
- Ewha Brain Institute, Ewha Womans University, Seoul 03760, Korea
- Department of Brain and Cognitive Sciences, Ewha Womans University, Seoul 03760, Korea
| | - Dae Woo Kim
- Department of Otorhinolaryngology-Head & Neck Surgery, Boramae Medical Center, Seoul National University College of Medicine, Seoul 07061, Korea
| |
Collapse
|
2
|
Chao LL. Olfactory and cognitive decrements in 1991 Gulf War veterans with gulf war illness/chronic multisymptom illness. Environ Health 2024; 23:14. [PMID: 38291474 PMCID: PMC10825982 DOI: 10.1186/s12940-024-01058-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Accepted: 01/26/2024] [Indexed: 02/01/2024]
Abstract
BACKGROUND Gulf War illness (GWI)/Chronic Multisymptom Illness (CMI) is a disorder related to military service in the 1991 Gulf War (GW). Prominent symptoms of GWI/CMI include fatigue, pain, and cognitive dysfunction. Although anosmia is not a typical GWI/CMI symptom, anecdotally some GW veterans have reported losing their sense smell shortly after the war. Because olfactory deficit is a prodromal symptom of neurodegenerative diseases like Parkinson's and Alzheimer's disease, and because we previously reported suggestive evidence that deployed GW veterans may be at increased risk for Mild Cognitive Impairment (MCI) and dementia, the current study examined the relationship between olfactory and cognitive function in deployed GW veterans. METHODS Eighty deployed GW veterans (mean age: 59.9 ±7.0; 4 female) were tested remotely with the University of Pennsylvania Smell Identification Test (UPSIT) and the Montreal Cognitive Assessment (MoCA). Veterans also completed self-report questionnaires about their health and deployment-related exposures and experiences. UPSIT and MoCA data from healthy control (HC) participants from the Parkinson's Progression Markers Initiative (PPMI) study were downloaded for comparison. RESULTS GW veterans had a mean UPSIT score of 27.8 ± 6.3 (range 9-37) and a mean MoCA score of 25.3 ± 2.8 (range 19-30). According to age- and sex-specific normative data, 31% of GW veterans (vs. 8% PPMI HCs) had UPSIT scores below the 10th percentile. Nearly half (45%) of GW veterans (vs. 8% PPMI HCs) had MoCA scores below the cut-off for identifying MCI. Among GW veterans, but not PPMI HCs, there was a positive correlation between UPSIT and MoCA scores (Spearman's ρ = 0.39, p < 0.001). There were no significant differences in UPSIT or MoCA scores between GW veterans with and without history of COVID or between those with and without Kansas GWI exclusionary conditions. CONCLUSIONS We found evidence of olfactory and cognitive deficits and a significant correlation between UPSIT and MoCA scores in a cohort of 80 deployed GW veterans, 99% of whom had CMI. Because impaired olfactory function has been associated with increased risk for MCI and dementia, it may be prudent to screen aging, deployed GW veterans with smell identification tests so that hypo- and anosmic veterans can be followed longitudinally and offered targeted neuroprotective therapies as they become available.
Collapse
Affiliation(s)
- Linda L Chao
- Departments of Radiology & Biomedical Imaging and Psychiatry & Behavioral Science, University of Calfiornia, 505 Parnassus Avenue, San Francisco, CA, 94143, USA.
- San Francisco Veterans Affairs Health Care System, 4150 Clement Street, San Francisco, CA, 94121, USA.
| |
Collapse
|
3
|
Chen H, Ding Y, Huang L, Zhong W, Lin X, Zhang B, Zheng Y, Xu X, Lou M, Yuan C. The Association of Allergy-Related and Non-Allergy-Related Olfactory Impairment with Cognitive Function in Older Adults: Two Cross- Sectional Studies. Curr Alzheimer Res 2024; 20:811-820. [PMID: 38409711 DOI: 10.2174/0115672050284179240215052257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 01/23/2024] [Accepted: 01/24/2024] [Indexed: 02/28/2024]
Abstract
BACKGROUND Evidence on the association of Olfactory Impairment (OI) with age-related cognitive decline is inconclusive, and the potential influence of allergy remains unclear. OBJECTIVE We aimed to evaluate the cross-sectional associations of allergy-related and non-allergy- related OI to cognitive function. METHODS We included 2,499 participants from the Health and Retirement Study (HRS)-Harmonized Cognitive Assessment Protocol (HCAP) sub-study and 1,086 participants from the English Longitudinal Study of Ageing (ELSA)-HCAP. The Olfactory Function Field Exam (OFFE) using Sniffin' Stick odor pens was used to objectively assess olfactory function and an olfactory score <6/11 indicated OI. Mini-Mental Status Examination (MMSE) was used to assess global cognitive function and define cognitive impairment (<24/30). A neuropsychologic battery was used to assess five cognitive domains. RESULTS Compared to non-OI participants, individuals with OI had lower MMSE z-score [βHRS = -0.33, 95% Confidence Interval (CI): -0.41 to -0.24; βELSA = -0.31, -0.43 to -0.18] and higher prevalence of cognitive impairment (Prevalence Ratio (PR)HRS = 1.46, 1.06 to 2.01; PRELSA = 1.63, 1.26 to 2.11). The associations were stronger for non-allergy-related OI (βHRS = -0.36; βELSA = -0.34) than for allergy-related OI (βHRS = -0.26; βELSA = 0.13). Similar associations were observed with domain- specific cognitive function measures. CONCLUSION OI, particularly non-allergy-related OI, was related to poorer cognitive function in older adults. Although the current cross-sectional study is subject to several limitations, such as reverse causality and residual confounding, the findings will provide insights into the OI-cognition association and enlighten future attention to non-allergy-related OI for the prevention of potential cognitive impairment.
Collapse
Affiliation(s)
- Hui Chen
- School of Public Health, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yihong Ding
- School of Public Health, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Liyan Huang
- School of Public Health, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Wansi Zhong
- Department of Neurology, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiaojun Lin
- School of Public Health, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Baoyue Zhang
- School of Public Health, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yan Zheng
- Human Phenome Institute, School of Life Sciences, Fudan University, Shanghai, China
| | - Xin Xu
- School of Public Health, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Min Lou
- Department of Neurology, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Changzheng Yuan
- School of Public Health, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| |
Collapse
|
4
|
Delgado-Lima AH, Bouhaben J, Martínez-Zujeros S, Pallardo-Rodil B, Gómez-Pavón J, Delgado-Losada ML. Could olfactory identification be a prognostic factor in detecting cognitive impairment risk in the elderly? GeroScience 2023:10.1007/s11357-023-00779-5. [PMID: 37084121 PMCID: PMC10119830 DOI: 10.1007/s11357-023-00779-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 03/20/2023] [Indexed: 04/22/2023] Open
Abstract
Aging contributes to the deterioration of the olfactory system in humans. Several studies indicate that the olfactory identification test alone may function as a screening test for olfactory dysfunction and they are more feasible to apply in clinical practice. Olfactory identification may be a predictor for cognitive impairment. Multiple studies have considered the use of odor identification as a measure to identify the conversion from normality to mild cognitive impairment or dementia. The objectives were (i) to elucidate the associations between cognitive status and olfactory identification performance in aging; (ii) understand the predictive value of olfactory capacity in identifying subjects with cognitive impairment risk; and (iii) to study how cognitive status and olfactory identification relate with other variables of wellness in aging, such as functional capabilities and clinical measures. For this purpose, a group of 149 participants (77.15 ± 7.29 years; 73 women of 76.7 ± 8 years and 76 men of 77.6 ± 6.52 years) were recruited and were subjected to a sociodemographic questionnaire, a psychological screening tool of general cognitive status, an olfactory identification evaluation, and clinical measures. The participants were divided into groups based on their cutoff scores of previous scientific reports about the Spanish version of Montreal Cognitive Assessment. Our results indicate an age-associated decline in olfactory identification ability and intensity of odor perception. The predictive ability of olfactory identification scores for the risk of mild and severe impairment is around 80%. Olfactory identification decreases with cognitive function. Performance in odor identification is associated with impairment of episodic memory and executive functions. These findings further our current understanding of the association between cognition and olfaction, and support olfactory assessment in screening those at higher risk of dementia.
Collapse
Affiliation(s)
- Alice Helena Delgado-Lima
- Experimental Psychology, Cognitive Processes and Speech Therapy Department, Faculty of Psychology, Complutense University of Madrid, 28223, Pozuelo de Alarcón, Spain
| | - Jaime Bouhaben
- Experimental Psychology, Cognitive Processes and Speech Therapy Department, Faculty of Psychology, Complutense University of Madrid, 28223, Pozuelo de Alarcón, Spain
| | - Sergio Martínez-Zujeros
- Geriatric Department, Hospital Central de La Cruz Roja "San José Y Santa Adela", 28003, Madrid, Spain
| | - Beatriz Pallardo-Rodil
- Geriatric Department, Hospital Central de La Cruz Roja "San José Y Santa Adela", 28003, Madrid, Spain
| | - Javier Gómez-Pavón
- Geriatric Department, Hospital Central de La Cruz Roja "San José Y Santa Adela", 28003, Madrid, Spain
| | - María Luisa Delgado-Losada
- Experimental Psychology, Cognitive Processes and Speech Therapy Department, Faculty of Psychology, Complutense University of Madrid, 28223, Pozuelo de Alarcón, Spain.
- Group of Neurosciences: Psychoneuroendocrinology, Neuroimaging and Molecular Genetics in Neuropsychiatric Diseases, Instituto de Investigación Sanitaria San Carlos (IdISSC), Hospital Clínico de Madrid, 28040, Madrid, Spain.
| |
Collapse
|
5
|
Kaya E, Göker AE. Olfactory Dysfunction: Its Association With Subjective Cognitive Impairment in Patients With Major Depression. J Nerv Ment Dis 2022; 210:172-178. [PMID: 34690274 DOI: 10.1097/nmd.0000000000001435] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
ABSTRACT Olfactory disorders may be observed together with cognitive impairment in patients with major depressive disorder (MDD). This study compared olfactory performances between patients with MDD and healthy controls and investigated the relationship between olfactory performance and subjective cognitive impairment in these patients. This study included 52 patients diagnosed with MDD and 46 healthy controls. The participants were evaluated in terms of their olfactory capacities (threshold, discrimination, and identification), subjective cognitive impairment, and depression. Although the olfactory threshold (OT) and olfactory discrimination scores were lower in patients with MDD compared with those in the control group, their olfactory identification scores did not differ significantly. OT was negatively correlated with subjective cognitive impairment and may serve as a determinant for subjective cognitive changes. Consequently, patients with MDD had lower olfactory performances compared with healthy controls. Finally, OT may be a component of subjective cognitive impairment in MDD.
Collapse
Affiliation(s)
| | - Ayşe Enise Göker
- Department of Otorhinolaryngology-Head and Neck Surgery, Okmeydani Training and Research Hospital, University of Health Science, Istanbul, Turkey
| |
Collapse
|
6
|
Devanand D, Lee S, Luchsinger JA, Andrews H, Goldberg T, Huey ED, Schupf N, Manly J, Stern Y, Kreisl WC, Mayeux R. Intact global cognitive and olfactory ability predicts lack of transition to dementia. Alzheimers Dement 2020; 16:326-334. [PMID: 31676234 PMCID: PMC7007828 DOI: 10.1016/j.jalz.2019.08.200] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
INTRODUCTION Odor identification deficits characterize Alzheimer's disease and other dementias. We examined if intact performance on brief cognitive and odor identification tests predicts lack of transition to dementia. METHODS In an urban community, 1037 older adults without dementia completed the 40-item University of Pennsylvania Smell Identification Test, which includes the 12-item Brief Smell Identification Test (B-SIT). Data from 749 participants followed up for 4 years were analyzed. RESULTS In covariate-adjusted survival analyses, impairment on the Blessed Orientation Memory Concentration Test and B-SIT each predicted dementia (n = 109), primarily Alzheimer's disease (n = 101). Among participants with intact olfactory (B-SIT ≥ 11/12 correct) and cognitive (Blessed Orientation Memory Concentration Test ≤ 5/28 incorrect) ability, 3.4% (4/117) transitioned to dementia during follow-up with no transitions in the 70-75 and 81-83 years age group quartiles. DISCUSSION Odor identification testing adds value to global cognitive testing, and together can identify individuals who rarely transition to dementia, thereby avoiding unnecessary diagnostic investigation.
Collapse
Affiliation(s)
- D.P. Devanand
- Division of Geriatric Psychiatry, New York State Psychiatric Institute, New York, NY, USA
- Department of Psychiatry, Columbia University Medical Center, New York, NY, USA
| | - Seonjoo Lee
- Research Foundation for Mental Hygiene and the Department of Biostatics, College of Physicians and Surgeons, Columbia University, New York City, New York, United States of America
| | - Jose A. Luchsinger
- Department of Medicine, Columbia University Medical Center, New York, NY, USA
| | - Howard Andrews
- Department of Biostatistics, Mailman School of Public Health, Columbia University Medical Center, New York, NY, USA
| | - Terry Goldberg
- Division of Geriatric Psychiatry, New York State Psychiatric Institute, New York, NY, USA
- Department of Psychiatry, Columbia University Medical Center, New York, NY, USA
| | - Edward D. Huey
- Department of Psychiatry, Columbia University Medical Center, New York, NY, USA
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, United States
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, United States
| | - Nicole Schupf
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, United States
- Department of Neurology Columbia University and the New York Presbyterian Hospital, New York, NY, USA
- Department of Epidemiology, Mailman School of Public Health, Columbia University Medical Center, New York, NY, USA
| | - Jennifer Manly
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, United States
- Department of Neurology Columbia University and the New York Presbyterian Hospital, New York, NY, USA
- The Gertrude H. Sergievsky Center, Columbia University, New York,NY, USA
| | - Yaakov Stern
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, United States
| | - William C. Kreisl
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, United States
| | - Richard Mayeux
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, United States
- The Gertrude H. Sergievsky Center, Columbia University, New York,NY, USA
| |
Collapse
|
7
|
De Nobrega AK, Lyons LC. Aging and the clock: Perspective from flies to humans. Eur J Neurosci 2020; 51:454-481. [PMID: 30269400 PMCID: PMC6441388 DOI: 10.1111/ejn.14176] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Revised: 09/10/2018] [Accepted: 09/17/2018] [Indexed: 12/15/2022]
Abstract
Endogenous circadian oscillators regulate molecular, cellular and physiological rhythms, synchronizing tissues and organ function to coordinate activity and metabolism with environmental cycles. The technological nature of modern society with round-the-clock work schedules and heavy reliance on personal electronics has precipitated a striking increase in the incidence of circadian and sleep disorders. Circadian dysfunction contributes to an increased risk for many diseases and appears to have adverse effects on aging and longevity in animal models. From invertebrate organisms to humans, the function and synchronization of the circadian system weakens with age aggravating the age-related disorders and pathologies. In this review, we highlight the impacts of circadian dysfunction on aging and longevity and the reciprocal effects of aging on circadian function with examples from Drosophila to humans underscoring the highly conserved nature of these interactions. Additionally, we review the potential for using reinforcement of the circadian system to promote healthy aging and mitigate age-related pathologies. Advancements in medicine and public health have significantly increased human life span in the past century. With the demographics of countries worldwide shifting to an older population, there is a critical need to understand the factors that shape healthy aging. Drosophila melanogaster, as a model for aging and circadian interactions, has the capacity to facilitate the rapid advancement of research in this area and provide mechanistic insights for targeted investigations in mammals.
Collapse
Affiliation(s)
- Aliza K De Nobrega
- Program in Neuroscience, Department of Biological Science, Florida State University, Tallahassee, Florida
| | - Lisa C Lyons
- Program in Neuroscience, Department of Biological Science, Florida State University, Tallahassee, Florida
| |
Collapse
|
8
|
Sudden Intrabulbar Amyloid Increase Simultaneously Disrupts Olfactory Bulb Oscillations and Odor Detection. Neural Plast 2019; 2019:3424906. [PMID: 31531013 PMCID: PMC6721117 DOI: 10.1155/2019/3424906] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 06/11/2019] [Accepted: 06/24/2019] [Indexed: 02/07/2023] Open
Abstract
There seems to be a correlation between soluble amyloid beta protein (Aβ) accumulation in the main olfactory bulb (OB) and smell deterioration in both Alzheimer's disease (AD) patients and animal models. Moreover, this loss of smell appears to be related to alterations in neural network activity in several olfactory-related circuits, including the OB, as has been observed in anesthetized animals and brain slices. It is possible that there is a correlation between these two pathological phenomena, but a direct and simultaneous evaluation of the acute and direct effect of Aβ on OB activity while animals are actually smelling has not been performed. Thus, here, we tested the effects of acute intrabulbar injection of Aβ at a low dose (200 pmol) on the OB local field potential before and during the presence of a hidden piece of smelly food. Our results show that Aβ decreases the power of OB network activity while impairing the animal's ability to reach the hidden food. We found a strong relationship between the power of the OB oscillations and the correlation between OBs and the olfactory detection test scores. These findings provide a direct link between Aβ-induced OB network dysfunction and smell loss in rodents, which could be extrapolated to AD patients.
Collapse
|
9
|
Zhang C, Wang X. Initiation of the age-related decline of odor identification in humans: A meta-analysis. Ageing Res Rev 2017; 40:45-50. [PMID: 28830800 DOI: 10.1016/j.arr.2017.08.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 08/11/2017] [Indexed: 10/19/2022]
Abstract
BACKGROUND Aging is an important contributor to olfactory system deterioration in humans, leading to increased health and safety risks as well as affecting the quality of life. However, it is currently unknown when age-related olfactory deterioration begins in humans and thus when to initiate interventions to prevent or slow it. OBJECTIVE To determine the decade in which olfactory function begins to deteriorate in healthy humans by determining when odor identification is first impaired. DATA SOURCE AND STUDY SELECTION Studies cited in the PubMed database were searched from its inception to March 2017 using the terms "olfac*" or "smell" and "ag*". The effect size of each comparison was calculated. RESULTS In this meta-analysis, the effect sizes as determined using Cohen's d for the comparisons between 30 and 39.9- and 40-49.9-year-olds was 0.06 (95% CI: -0.17 to 0.29), between 40-49.9-year-olds was 0.62 (95% CI: 0.20-1.04), considered a medium effect size, and between 35-55-year-olds and those >55years old was 1.12 (95% CI: 1.06-1.45), considered a very large effect. CONCLUSION Olfactory function deterioration, as determined by an impaired ability to identify odors, starts in the fifth decade of life in healthy humans.
Collapse
|
10
|
Wang J, Sun X, Yang QX. Early Aging Effect on the Function of the Human Central Olfactory System. J Gerontol A Biol Sci Med Sci 2017; 72:1007-1014. [PMID: 27289103 DOI: 10.1093/gerona/glw104] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 04/27/2016] [Indexed: 01/24/2023] Open
Abstract
During normal aging process, the smell function declines significantly, starting from the sixth decade of age. While it has been shown that activity in the central olfactory system of seniors responding to odor stimulation is significantly less than that of young people, no information of the aging effect on the functions of this system during normal adulthood and early aging has been gathered. In this study, we used functional magnetic resonance imaging to investigate the olfaction-related brain activity in the central olfactory structures of 43 healthy adult volunteers aged from 22 to 64 years. The participants' smell identification function was negatively correlated with age (r = -.32, p = .037). Significant negative correlation was observed between age and the olfaction-related activities in the bilateral dorsolateral prefrontal cortex, left insular cortex, and left orbitofrontal cortex (p < .001, corrected with cluster size ≥28 voxels). There was no significant correlation observed between age and the activity in the primary olfactory cortex detected in this age group. These results suggest that age-related functional decline in the human brain is more prominent in the secondary and higher-order central olfactory structures than the primary olfactory cortex in the early aging process.
Collapse
Affiliation(s)
- Jianli Wang
- Department of Radiology, Pennsylvania State University College of Medicine, Hershey
| | - Xiaoyu Sun
- Department of Radiology, Pennsylvania State University College of Medicine, Hershey
| | - Qing X Yang
- Departments of Radiology and Neurosurgery, Pennsylvania State University College of Medicine, Hershey
| |
Collapse
|
11
|
Heterogeneity of odorant identification impairment in patients with Alzheimer's Disease. Sci Rep 2017; 7:4798. [PMID: 28684764 PMCID: PMC5500500 DOI: 10.1038/s41598-017-05201-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 05/24/2017] [Indexed: 02/01/2023] Open
Abstract
Alzheimer’s disease (AD) patients exhibit olfactory dysfunction. However, the olfactory declineti precise nature is not fully understood. One hundred patients (60 AD, 28 amnestic mild cognitive impairment (aMCI), 12 Normal) were enrolled. All participants underwent olfactory function testing using an odour stick identification test for Japanese (OSIT-J). OSIT-J scores were significantly correlated with recall. We classified OSIT-J odorants into three groups: Category I, odorants that were difficult for normal aged subjects to identify; Category II, odorants that became harder to accurately identify with cognitive decline; and Category III, odorants that even AD patients could identify. We defined a “cognitive subset” consisting of six Category II OSIT-J odorants (perfume, rose, Japanese cypress, curry, India ink and gas leak odour). The ability to identify “cognitive subset” odours was significantly better indicator of cognitive status than the ability to identify “non-cognitive subset”, which consisted of the six remaining items. The ability to identify the gas leak odorant was decreased early in the aMCI stage, suggesting a need to reconsider the odours used to signal gas leaks. The “cognitive subset” would provide a more convenient and effective biomarker for diagnosing dementia in clinical settings.
Collapse
|
12
|
Ward AM, Calamia M, Thiemann E, Dunlap J, Tranel D. Association between olfaction and higher cortical functions in Alzheimer's disease, mild cognitive impairment, and healthy older adults. J Clin Exp Neuropsychol 2016; 39:646-658. [PMID: 27868477 DOI: 10.1080/13803395.2016.1253667] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
INTRODUCTION Neural regions important for smell are proximal and closely connected to cortical areas that have been strongly implicated in higher order functions of value-based decision making and emotional memory. The integrity of these neural regions are affected in aging and neurodegenerative conditions. Two specific predictions follow from these neuroanatomical arrangements-namely, that olfaction would be associated with value-based decision making and with emotional memory. METHOD To test these predictions, we measured these different capacities in participants with presumed varying degrees of integrity of the relevant brain structures: specifically, 13 patients with Alzheimer's disease, 8 patients with mild cognitive impairment, and 20 healthy older adults. The participants completed detailed tests of olfaction, value-based decision making, emotional memory, and general cognitive ability. RESULTS Olfactory functioning was significantly associated with emotional and nonemotional memory. The association was especially strong and consistent for memory recall with olfaction, explaining as much as 10% additional variance over and above general cognition. Olfactory functioning was not strongly or consistently associated with decision making over and above general cognition. CONCLUSION Olfaction is a strong predictor of memory recall. These findings may contribute to a better understanding of olfaction and specific cognitive domains known to be affected by aging and implicated in neurodegenerative disease.
Collapse
Affiliation(s)
- Amanda M Ward
- a Department of Psychological and Brain Sciences , University of Iowa , Iowa City , IA , USA
| | - Matthew Calamia
- b Department of Psychology , Louisiana State University , Baton Rouge , LA , USA
| | - Erin Thiemann
- a Department of Psychological and Brain Sciences , University of Iowa , Iowa City , IA , USA
| | - Jamie Dunlap
- a Department of Psychological and Brain Sciences , University of Iowa , Iowa City , IA , USA
| | - Daniel Tranel
- a Department of Psychological and Brain Sciences , University of Iowa , Iowa City , IA , USA.,c Department of Neurology , University of Iowa Carver College of Medicine , Iowa City , IA , USA
| |
Collapse
|
13
|
Liang X, Ding D, Zhao Q, Guo Q, Luo J, Hong Z. Association between olfactory identification and cognitive function in community-dwelling elderly: the Shanghai aging study. BMC Neurol 2016; 16:199. [PMID: 27765032 PMCID: PMC5073423 DOI: 10.1186/s12883-016-0725-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 10/15/2016] [Indexed: 11/10/2022] Open
Abstract
Background The smell sense reduction was considered to represent the potentially warning of early stage of neurodegenerative disorders. The Shanghai Aging Study provided us a unique opportunity to explore the association between olfactory identification (OI) and cognitive function among community-dwelling elderly in China. Methods OI of each participant was measured by the 12-item identification tests from Sniffin’ Sticks Screening test (SSST-12). Participants with mild cognitive impairment (MCI) were diagnosed by Petersen criteria. We used the logistic regression analysis to explore the association between OI scores and cognitive function by adjusting potential confounders. Results Among 1782 non-demented participants, 345 (19.4 %) participants were diagnosed as MCI. The mean OI score for participants with MCI [7.1 (SD 2.3)] was significantly lower than that for those with normal cognition [8.2 (SD 2.0), P < 0.0001]. After adjusted for age, gender, education, lifestyles, medical history, Apolipoprotein E genotype, lower OI score was found to be an independent influence factor related to MCI (OR 1.19, 95 % CI 1.11–1.27). Conclusions Our study suggests that poor OI may be associated with MCI in elderly population. Further prospective studies may confirm the OI as a reliable and early marker predicting the decline of cognitive function.
Collapse
Affiliation(s)
- Xiaoniu Liang
- Institute of Neurology, Huashan Hospital, Fudan University, WHO Collaborating Center for Research and Training in Neurosciences, Shanghai, 200040, China.,Department of Biostatistics, School of Public Health, Fudan University, Shanghai, 200032, China.,The Key Laboratory of Public Health Safety, Fudan University, Shanghai, 200032, China.,National Clinical Research Center for Aging Diseases, Shanghai, 200040, China
| | - Ding Ding
- Institute of Neurology, Huashan Hospital, Fudan University, WHO Collaborating Center for Research and Training in Neurosciences, Shanghai, 200040, China. .,National Clinical Research Center for Aging Diseases, Shanghai, 200040, China.
| | - Qianhua Zhao
- Institute of Neurology, Huashan Hospital, Fudan University, WHO Collaborating Center for Research and Training in Neurosciences, Shanghai, 200040, China.,National Clinical Research Center for Aging Diseases, Shanghai, 200040, China
| | - Qihao Guo
- Institute of Neurology, Huashan Hospital, Fudan University, WHO Collaborating Center for Research and Training in Neurosciences, Shanghai, 200040, China.,National Clinical Research Center for Aging Diseases, Shanghai, 200040, China
| | - Jianfeng Luo
- Department of Biostatistics, School of Public Health, Fudan University, Shanghai, 200032, China.,The Key Laboratory of Public Health Safety, Fudan University, Shanghai, 200032, China
| | - Zhen Hong
- Institute of Neurology, Huashan Hospital, Fudan University, WHO Collaborating Center for Research and Training in Neurosciences, Shanghai, 200040, China.,National Clinical Research Center for Aging Diseases, Shanghai, 200040, China
| | | |
Collapse
|
14
|
Olofsson JK, Josefsson M, Ekström I, Wilson D, Nyberg L, Nordin S, Nordin Adolfsson A, Adolfsson R, Nilsson LG, Larsson M. Long-term episodic memory decline is associated with olfactory deficits only in carriers of ApoE-є4. Neuropsychologia 2016; 85:1-9. [DOI: 10.1016/j.neuropsychologia.2016.03.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 03/03/2016] [Accepted: 03/04/2016] [Indexed: 02/06/2023]
|
15
|
Xie AJ, Liu EJ, Huang HZ, Hu Y, Li K, Lu Y, Wang JZ, Zhu LQ. Cnga2 Knockout Mice Display Alzheimer’s-Like Behavior Abnormities and Pathological Changes. Mol Neurobiol 2015; 53:4992-9. [DOI: 10.1007/s12035-015-9421-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2015] [Accepted: 09/02/2015] [Indexed: 10/23/2022]
|
16
|
Grashow R, Sparrow D, Hu H, Weisskopf MG. Cumulative lead exposure is associated with reduced olfactory recognition performance in elderly men: The Normative Aging Study. Neurotoxicology 2015; 49:158-64. [PMID: 26121922 DOI: 10.1016/j.neuro.2015.06.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 06/05/2015] [Accepted: 06/23/2015] [Indexed: 10/23/2022]
Abstract
INTRODUCTION Olfactory dysfunction has been identified as an early warning sign for Alzheimer's disease, Parkinson's disease, dementia and more. A few occupational and environmental exposures have also been associated with reduced olfactory function, although the effects of long term environmental exposure to lead on olfactory dysfunction have not been explored. Here we performed olfactory recognition testing in elderly men in a community-dwelling cohort and examined the association with cumulative lead exposure, as assessed by lead in tibial and patellar bone. METHODS Olfactory recognition was measured in 165 men from the Normative Aging Study (NAS) who had previously taken part in bone lead measurements using K-X-ray fluorescence (KXRF). Olfactory recognition was measured using the University of Pennsylvania Smell Identification Test (UPSIT). Associations between olfactory recognition, global cognition and cumulative lead exposure were estimated using linear regression, with additional adjustment for age, smoking, and functional polymorphism status for hemochromatosis (HFE), transferrin (TfC2), glutathione-s-transferase Pi1 (GSTP1) and apolipoprotein E (APOE) genotypes. Sensitivity analyses explored olfactory recognition in men with high global cognitive function as measured using the Mini-Mental Status Exam (MMSE). RESULTS The average age of the NAS participants at the time of olfactory recognition testing was 80.3 (standard deviation or SD=5.7) years. Mean tibia lead was 16.3 (SD=12.0) μg/g bone, mean patella lead was 22.4 (SD=14.4)μg/g bone, and mean UPSIT score was 26.9 out of 40 (SD=7.0). Consistent with previous findings, age at olfaction testing was negatively associated with UPSIT score. Tibia (but not patella) bone lead was negatively associated with olfaction recognition (per 15 μg/g tibia lead: β=-1.57; 95% CI: -2.93, -0.22; p=0.02) in models adjusted for smoking and age. Additional adjustment for education did not significantly change results. Of all the genes explored, only the presence of one or more HFE variant alleles was significantly associated with olfaction recognition (HFE β=2.26; 95% CI: 0.09, 4.43; p=0.04). In a model containing the HFE term and a lead term, the tibia lead parameter estimate dropped by 21% (per 15 μg/g tibia lead: β=-1.25; 95% CI: -2.64, 0.14; p=0.08) while the HFE term dropped 15% (β=1.91; 95% CI: -0.28, 4.10; p=0.09). None of the other gene terms were associated with olfactory recognition in this cohort, nor were any gene-lead interaction terms significant. Additional sensitivity analysis in men with MMSE scores of 25 or higher (n=149) showed a similar but slightly attenuated association between lead and olfactory recognition (per 15 μg/g tibia lead β=-1.39; 95% CI: -3.00, 0.22; p=0.09). CONCLUSION Cumulative exposure to lead is associated with reduced olfactory recognition in a cohort of elderly men. The association was similar but not significant in men with better cognitive function as measured by the MMSE. Iron metabolism gene status may also affect olfactory function.
Collapse
Affiliation(s)
- Rachel Grashow
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA; Department of Civil and Environmental Engineering, Northeastern University, Boston, MA, USA.
| | - David Sparrow
- VA Boston Healthcare System, Boston University Schools of Public Health and Medicine, Boston, MA, USA; Department of Medicine, Boston University School of Medicine, Boston, MA, USA
| | - Howard Hu
- Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada
| | - Marc G Weisskopf
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| |
Collapse
|
17
|
Vyhnalek M, Magerova H, Andel R, Nikolai T, Kadlecova A, Laczo J, Hort J. Olfactory identification in amnestic and non-amnestic mild cognitive impairment and its neuropsychological correlates. J Neurol Sci 2015; 349:179-84. [DOI: 10.1016/j.jns.2015.01.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 01/07/2015] [Accepted: 01/08/2015] [Indexed: 01/16/2023]
|
18
|
Activation of Glycogen Synthase Kinase-3 Mediates the Olfactory Deficit-Induced Hippocampal Impairments. Mol Neurobiol 2014; 52:1601-1617. [DOI: 10.1007/s12035-014-8953-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Accepted: 10/20/2014] [Indexed: 01/04/2023]
|
19
|
Olfactory Dysfunction in the Elderly: Basic Circuitry and Alterations with Normal Aging and Alzheimer's Disease. CURRENT GERIATRICS REPORTS 2014; 3:91-100. [PMID: 25045620 DOI: 10.1007/s13670-014-0080-y] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Preclinical detection of Alzheimer disease is critical to determining at-risk individuals in order to improve patient and caregiver planning for their futures and to identify individuals likely to benefit from treatment as advances in therapeutics develop over time. Identification of olfactory dysfunction at the preclinical and early stages of the disease is a potentially useful method to accomplish these goals. We first review basic olfactory circuitry. We then evaluate the evidence of pathophysiological change in the olfactory processing pathways during aging and Alzheimer disease in both human and animal models. We also review olfactory behavioral studies during these processes in both types of models. In doing so, we suggest hypotheses about the localization and mechanisms of olfactory dysfunction and identify important avenues for future work.
Collapse
|
20
|
Makizako M, Makizako H, Doi T, Uemura K, Tsutsumimoto K, Miyaguchi H, Shimada H. Olfactory identification and cognitive performance in community-dwelling older adults with mild cognitive impairment. Chem Senses 2013; 39:39-46. [PMID: 24200528 DOI: 10.1093/chemse/bjt052] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Olfactory impairment constitutes one of the earliest signs of Alzheimer's disease in older adults with mild cognitive impairment. We investigated which aspects of neuropsychological measures are correlated with olfactory identification performance among older adults with mild cognitive impairment. Total of 220 participants with mild cognitive impairment (mean age 71.7 years) were examined. Odor identification was assessed using the Open Essence test. Participants underwent comprehensive neurocognitive evaluation, including measures of verbal memory, visual memory, working memory, attention/executive function, and processing speed. We examined associations between olfactory function and cognitive performance scores. Participants with severe hyposmia exhibited significantly poor verbal and visual memory performance, attention/executive function, and slower processing speed scores compared with those without severe hyposmia. In multivariable logistic regression models, better performance scores on verbal and visual memory were significantly associated with decreased likelihood of severe hyposmia after adjusting for age, sex, education, and other cognitive performance scores. These findings suggest that olfactory impairment might be more closely associated with memory loss compared with other aspects of cognitive functioning in mild cognitive impairment subjects.
Collapse
Affiliation(s)
- Mihoko Makizako
- Section for Health Promotion, Department for Research and Development to Support Independent Life of Elderly, Center for Gerontology and Social Science, National Center for Geriatrics and Gerontology, 35 Gengo, Morioka-machi, Obu, Aichi 474-8511, Japan.
| | | | | | | | | | | | | |
Collapse
|
21
|
Schubert CR, Cruickshanks KJ, Fischer ME, Huang GH, Klein R, Pankratz N, Zhong W, Nondahl DM. Odor identification and cognitive function in the Beaver Dam Offspring Study. J Clin Exp Neuropsychol 2013; 35:669-76. [PMID: 23789858 DOI: 10.1080/13803395.2013.809701] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Olfactory impairment is associated with cognitive impairment in older adults but less is known about the association of olfactory impairment and cognitive function in middle-aged adults. The association between olfactory impairment and cognitive function tests of attention, processing speed, and executive and psychomotor function was explored in 2837 participants (21-84 years; mean age 49 years) in the Beaver Dam Offspring Study. Among middle-aged participants (aged 35-64 years), those with impairment on an odor identification test took significantly longer to complete the Trail Making Test (TMT-A and TMT-B) and the Grooved Peg Board (GPB) test, than those without olfactory impairment in regression models adjusted for multiple factors. Similar results were found for the TMT-A and TMT-B, but not the GPB, in the whole cohort. Olfactory impairment was associated with poorer performance on cognitive function tests in a primarily middle-aged cohort.
Collapse
Affiliation(s)
- Carla R Schubert
- a Department of Ophthalmology and Visual Sciences , University of Wisconsin School of Medicine and Public Health , Madison , WI , USA
| | | | | | | | | | | | | | | |
Collapse
|
22
|
Lipnicki DM, Sachdev PS, Crawford J, Reppermund S, Kochan NA, Trollor JN, Draper B, Slavin MJ, Kang K, Lux O, Mather KA, Brodaty H. Risk factors for late-life cognitive decline and variation with age and sex in the Sydney Memory and Ageing Study. PLoS One 2013; 8:e65841. [PMID: 23799051 PMCID: PMC3683032 DOI: 10.1371/journal.pone.0065841] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 04/29/2013] [Indexed: 11/18/2022] Open
Abstract
Introduction An aging population brings increasing burdens and costs to individuals and society arising from late-life cognitive decline, the causes of which are unclear. We aimed to identify factors predicting late-life cognitive decline. Methods Participants were 889 community-dwelling 70–90-year-olds from the Sydney Memory and Ageing Study with comprehensive neuropsychological assessments at baseline and a 2-year follow-up and initially without dementia. Cognitive decline was considered as incident mild cognitive impairment (MCI) or dementia, as well as decreases in attention/processing speed, executive function, memory, and global cognition. Associations with baseline demographic, lifestyle, health and medical factors were determined. Results All cognitive measures showed decline and 14% of participants developed incident MCI or dementia. Across all participants, risk factors for decline included older age and poorer smelling ability most prominently, but also more education, history of depression, being male, higher homocysteine, coronary artery disease, arthritis, low health status, and stroke. Protective factors included marriage, kidney disease, and antidepressant use. For some of these factors the association varied with age or differed between men and women. Additional risk and protective factors that were strictly age- and/or sex-dependent were also identified. We found salient population attributable risks (8.7–49.5%) for older age, being male or unmarried, poor smelling ability, coronary artery disease, arthritis, stroke, and high homocysteine. Discussion Preventing or treating conditions typically associated with aging might reduce population-wide late-life cognitive decline. Interventions tailored to particular age and sex groups may offer further benefits.
Collapse
Affiliation(s)
- Darren M. Lipnicki
- Centre for Healthy Brain Ageing, School of Psychiatry, Faculty of Medicine, University of New South Wales, Australia
| | - Perminder S. Sachdev
- Centre for Healthy Brain Ageing, School of Psychiatry, Faculty of Medicine, University of New South Wales, Australia
- Neuropsychiatric Institute, Prince of Wales Hospital, New South Wales, Australia
- Primary Dementia Collaborative Research Centre, School of Psychiatry, Faculty of Medicine, University of New South Wales, Australia
- * E-mail:
| | - John Crawford
- Centre for Healthy Brain Ageing, School of Psychiatry, Faculty of Medicine, University of New South Wales, Australia
| | - Simone Reppermund
- Centre for Healthy Brain Ageing, School of Psychiatry, Faculty of Medicine, University of New South Wales, Australia
| | - Nicole A. Kochan
- Centre for Healthy Brain Ageing, School of Psychiatry, Faculty of Medicine, University of New South Wales, Australia
- Neuropsychiatric Institute, Prince of Wales Hospital, New South Wales, Australia
| | - Julian N. Trollor
- Centre for Healthy Brain Ageing, School of Psychiatry, Faculty of Medicine, University of New South Wales, Australia
- Department of Developmental Disability Neuropsychiatry, School of Psychiatry, Faculty of Medicine, University of New South Wales, Australia
| | - Brian Draper
- Centre for Healthy Brain Ageing, School of Psychiatry, Faculty of Medicine, University of New South Wales, Australia
- Primary Dementia Collaborative Research Centre, School of Psychiatry, Faculty of Medicine, University of New South Wales, Australia
- Academic Department for Old Age Psychiatry, Prince of Wales Hospital, New South Wales, Australia
| | - Melissa J. Slavin
- Centre for Healthy Brain Ageing, School of Psychiatry, Faculty of Medicine, University of New South Wales, Australia
- Primary Dementia Collaborative Research Centre, School of Psychiatry, Faculty of Medicine, University of New South Wales, Australia
| | - Kristan Kang
- Centre for Healthy Brain Ageing, School of Psychiatry, Faculty of Medicine, University of New South Wales, Australia
| | - Ora Lux
- Centre for Healthy Brain Ageing, School of Psychiatry, Faculty of Medicine, University of New South Wales, Australia
- South-Eastern Area Laboratory Services, Prince of Wales Hospital, New South Wales, Australia
| | - Karen A. Mather
- Centre for Healthy Brain Ageing, School of Psychiatry, Faculty of Medicine, University of New South Wales, Australia
- Neuropsychiatric Institute, Prince of Wales Hospital, New South Wales, Australia
| | - Henry Brodaty
- Centre for Healthy Brain Ageing, School of Psychiatry, Faculty of Medicine, University of New South Wales, Australia
- Primary Dementia Collaborative Research Centre, School of Psychiatry, Faculty of Medicine, University of New South Wales, Australia
- Academic Department for Old Age Psychiatry, Prince of Wales Hospital, New South Wales, Australia
| |
Collapse
|
23
|
The olfactory system in Alzheimer’s disease: Pathology, pathophysiology and pathway for therapy. Transl Neurosci 2013. [DOI: 10.2478/s13380-013-0108-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
AbstractOlfaction is frequently mentioned as a “neglected sense”, although the olfactory system has several interesting and unique anatomical and physiological features. Olfactory involvement is present in several degenerative disorders, especially in Alzheimer’s disease (AD). The peripheral and central parts of the olfactory system are damaged even in the early stages of AD, manifesting in profound olfactory deficits. Besides the early pathology, the olfactory system may be involved in the pathogenesis of AD by providing a route of entry for pathological agents still unknown. In contrast to this olfactory vector hypothesis, the olfactory system can be used to deliver therapeutic agents in AD, such as nerve growth factor and insulin, by decreasing the side-effects of the therapy or providing a non-invasive method of delivery.
Collapse
|
24
|
Toledano A, Borromeo S, Luna G, Molina E, Solana AB, García-Polo P, Hernández JA, Álvarez-linera J. Estudio objetivo del olfato mediante resonancia magnética funcional. ACTA OTORRINOLARINGOLOGICA ESPANOLA 2012; 63:280-5. [DOI: 10.1016/j.otorri.2012.01.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Revised: 01/15/2012] [Accepted: 01/16/2012] [Indexed: 11/26/2022]
|
25
|
Toledano A, Borromeo S, Luna G, Molina E, Solana AB, García-Polo P, Hernández JA, Álvarez-linera J. Objective Assessment of Olfactory Function Using Functional Magnetic Resonance Imaging. ACTA ACUST UNITED AC 2012. [DOI: 10.1016/j.otoeng.2012.07.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
26
|
Olfactory deficits induce neurofilament hyperphosphorylation. Neurosci Lett 2012; 506:180-3. [DOI: 10.1016/j.neulet.2011.10.076] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Revised: 09/09/2011] [Accepted: 10/29/2011] [Indexed: 12/21/2022]
|
27
|
Wehling E, Nordin S, Espeseth T, Reinvang I, Lundervold AJ. Unawareness of olfactory dysfunction and its association with cognitive functioning in middle aged and old adults. Arch Clin Neuropsychol 2011; 26:260-9. [PMID: 21474482 DOI: 10.1093/arclin/acr019] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The objective of this study was (a) to investigate the accordance of self-reported and objectively assessed olfactory functioning and (b) to compare performance on cognitive tests of individuals unaware of their olfactory dysfunction with individuals aware of their olfactory status. Two hundred forty participants, constituting two age groups, were evaluated with the Scandinavian Odor Identification Test, a question of self-evaluated olfactory function, tests of cognitive function, and a memory questionnaire. The proportion of individuals being unaware of an olfactory dysfunction was high in both middle aged (86%) and old (78%) participants. Performance on neuropsychological tests showed that persons unaware of their olfactory dysfunction performed poorer on tests of verbal learning and memory and attention/processing speed compared to individuals aware of a normal olfactory status as well as individuals aware of their olfactory dysfunction. The clinical relevance of unawareness of olfactory dysfunction, as suggested earlier, needs further investigation and stresses the need of an extensive multi-modal and longitudinal assessment of unawareness of sensory and cognitive function to learn more about the facets of the concept of unawareness.
Collapse
Affiliation(s)
- Eike Wehling
- Department of Biological and Medical Psychology, University of Bergen, Norway.
| | | | | | | | | |
Collapse
|
28
|
Makowska I, Kloszewska I, Grabowska A, Szatkowska I, Rymarczyk K. Olfactory Deficits in Normal Aging and Alzheimer's Disease in the Polish Elderly Population. Arch Clin Neuropsychol 2011; 26:270-9. [DOI: 10.1093/arclin/acr011] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
|
29
|
Olofsson JK, Rönnlund M, Nordin S, Nyberg L, Nilsson LG, Larsson M. Odor identification deficit as a predictor of five-year global cognitive change: interactive effects with age and ApoE-epsilon4. Behav Genet 2009; 39:496-503. [PMID: 19633944 DOI: 10.1007/s10519-009-9289-5] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2009] [Accepted: 07/08/2009] [Indexed: 11/28/2022]
Abstract
Olfactory impairments are present in common neurodegenerative disorders and predict conversion to dementia in non-demented individuals with cognitive impairment. In cognitively intact elderly, evidence is sparse regarding the role of olfactory deficits in predicting cognitive impairment. The present study investigated predictors of 5-year prospective decline in the Mini-Mental State Examination (MMSE) in a large (n = 501), population-based sample of elderly (65-90 years) individuals. All participants were genotyped for the ApoE gene, assessed for health factors, and were non-demented at the baseline assessment. After partialling out the influences of demographic and health-factors at baseline and dementia at follow-up, poor odor identification ability in combination with older age and the ApoE-epsilon4 allele predicted larger prospective global cognitive decline. This effect could not be produced by a vocabulary test. In sum, the findings suggest that an olfactory deficit can dissociate between benign and malign global cognitive development in non-demented, very old epsilon4-carriers, who are at high risk of developing dementia.
Collapse
|
30
|
Lehrner J, Pusswald G, Gleiss A, Auff E, Dal-Bianco P. Odor Identification and Self-reported Olfactory Functioning in Patients with Subtypes of Mild Cognitive Impairment. Clin Neuropsychol 2009; 23:818-30. [DOI: 10.1080/13854040802585030] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
31
|
Olfactory identification in non-demented elderly population and in mild cognitive impairment: a comparison of performance in clinical odor identification versus Boston Naming Test. J Neural Transm (Vienna) 2009; 116:891-5. [PMID: 19551462 DOI: 10.1007/s00702-009-0235-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2008] [Accepted: 04/22/2009] [Indexed: 10/20/2022]
Abstract
Performance in olfactory identification was studied in mild cognitive impairment (MCI), using slightly expanded standard clinical approach to study the olfactory nerve. Four hundred and eighty-six cognitively normal individuals and 72 individuals with MCI underwent spontaneous and cued odor identification and delayed odor recall. Performance in these was compared with the performance in the CERAD version of the Boston Naming Test (BNT). The individuals with MCI scores significantly worse in all tests compared with controls, but the performance in tests assessing odor were less impaired than performance in the BNT. Standard assessment of olfactory nerve function is not sufficient to study cognitive impairment in MCI.
Collapse
|
32
|
Pardini M, Huey ED, Cavanagh AL, Grafman J. Olfactory function in corticobasal syndrome and frontotemporal dementia. ACTA ACUST UNITED AC 2009; 66:92-6. [PMID: 19139305 DOI: 10.1001/archneurol.2008.521] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
BACKGROUND Formal olfactory testing may be useful as a bedside tool to help differentiate between conditions such as atypical parkinsonism, dementia, and psychiatric conditions. However, the neural basis of olfactory dysfunction, the effect of concurrent cognitive deficits on olfactory testing results, and the exact prevalence of olfactory deficits in populations with corticobasal syndrome (CBS) and the frontal variant of frontotemporal dementia (FTD-FV) are to date unclear. OBJECTIVE To assess the prevalence and the neural basis of olfactory recognition deficits in patients with a clinical diagnosis of CBS or FTD-FV. DESIGN Retrospective study of clinical, neuropsychological, and imaging data. SETTING National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland. PARTICIPANTS Twenty-five patients with CBS, 22 with FTD-FV, and 12 age-matched control subjects. MAIN OUTCOME MEASURES Results of neuropsychological evaluation, formal olfactory recognition testing (University of Pennsylvania Smell Identification Test [UPSIT]), and voxel-based morphometry analysis of structural magnetic resonance images of the brain. RESULTS Mean UPSIT percentile scores were 31.6% for the CBS group and 9.5% for the FTD-FV group. The voxel-based morphometry correlations between local gray matter and UPSIT scores showed a significant volume effect in the right midfrontal gyrus for the FTD-FV patients and in the right insula, right midfrontal gyrus, and bilateral inferior frontal gyrus for the patients with CBS. A linear regression analysis of the UPSIT scores revealed as significant predictors the general memory score of the Wechsler Memory Scale and the Boston Naming Test total score for the patients with FTD-FV and the Mattis Dementia Rating Scale total score for the patients with CBS. CONCLUSIONS Our data showed a more severe olfactory impairment for CBS patients than previously reported. We also showed a significant relationship between formal olfactory recognition testing scores and specific cognitive domains. These findings could be useful to clinically differentiate FTD-FV and CBS from other dementing illnesses and movement disorders.
Collapse
Affiliation(s)
- Matteo Pardini
- Cognitive Neuroscience Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892-1440, USA
| | | | | | | |
Collapse
|
33
|
Lohmann E, Leclere L, De Anna F, Lesage S, Dubois B, Agid Y, Dürr A, Brice A. A clinical, neuropsychological and olfactory evaluation of a large family with LRRK2 mutations. Parkinsonism Relat Disord 2008; 15:273-6. [PMID: 18718805 DOI: 10.1016/j.parkreldis.2008.06.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2008] [Revised: 06/13/2008] [Accepted: 06/20/2008] [Indexed: 11/27/2022]
Abstract
We evaluated the neurological and neuropsychological profiles and olfaction as presymptomatic markers in a large family with Parkinson disease (PD) caused by the G2019S mutation in the LRRK2 gene. Five affected family members, 14 asymptomatic mutation carriers and 15 non-carriers were compared. Patients had typical dopa-responsive PD, frequently associated with cognitive impairment. Asymptomatic carriers and non-carriers could not be distinguished because of their neuropsychological status, the presence of depression or olfactory impairment. We were therefore unable to identify a presymptomatic marker of LRRK2-related PD.
Collapse
Affiliation(s)
- Ebba Lohmann
- INSERM, UMR_S679 Neurologie & Thérapeutique Expérimentale, F-75013 Paris, France
| | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Reed TT, Pierce WM, Turner DM, Markesbery WR, Allan Butterfield D. Proteomic identification of nitrated brain proteins in early Alzheimer's disease inferior parietal lobule. J Cell Mol Med 2008; 13:2019-2029. [PMID: 18752637 DOI: 10.1111/j.1582-4934.2008.00478.x] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive decline in multiple cognitive domains. Its pathological hallmarks include senile plaques and neurofibrillary tangles. Mild cognitive impairment (MCI) is the earliest detectable stage of AD with limited symptomology and no dementia. The yearly conversion rate of patients from MCI to AD is 10-15%, although conversion back to normal is possible in a small percentage. Early diagnosis of AD is important in an attempt to intervene or slow the advancement of the disease. Early AD (EAD) is a stage following MCI and characterized by full-blown dementia; however, information involving EAD is limited. Oxidative stress is well-established in MCI and AD, including protein oxidation. Protein nitration also is an important oxidative modification observed in MCI and AD, and proteomic analysis from our laboratory identified nitrated proteins in both MCI and AD. Therefore, in the current study, a proteomics approach was used to identify nitrated brain proteins in the inferior parietal lobule from four subjects with EAD. Eight proteins were found to be significantly nitrated in EAD: peroxiredoxin 2, triose phosphate isomerase, glutamate dehydrogenase, neuropolypeptide h3, phosphoglycerate mutase1, H(+)- transporting ATPase, alpha-enolase and fructose-1,6-bisphosphate aldolase. Many of these proteins are also nitrated in MCI and late-stage AD, making this study the first to our knowledge to link nitrated proteins in all stages of AD. These results are discussed in terms of potential involvement in the progression of this dementing disorder.
Collapse
Affiliation(s)
- Tanea T Reed
- Department of Chemistry, University of Kentucky, Lexington, KY, USA
| | - William M Pierce
- Department of Pharmacology, University of Louisville School of Medicine and VAMC, Louisville, KY, USA
| | - Delano M Turner
- Department of Pharmacology, University of Louisville School of Medicine and VAMC, Louisville, KY, USA
| | - William R Markesbery
- Departments of Pathology and Neurology, Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - D Allan Butterfield
- Department of Chemistry, University of Kentucky, Lexington, KY, USA.,Center of Membrane Sciences, University of Kentucky, Lexington, KY, USA
| |
Collapse
|
35
|
Schubert CR, Carmichael LL, Murphy C, Klein BEK, Klein R, Cruickshanks KJ. Olfaction and the 5-year incidence of cognitive impairment in an epidemiological study of older adults. J Am Geriatr Soc 2008; 56:1517-21. [PMID: 18662205 DOI: 10.1111/j.1532-5415.2008.01826.x] [Citation(s) in RCA: 137] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVES To determine whether odor identification ability is associated with the 5-year incidence of cognitive impairment in a large population of older adults with normal cognition at baseline and whether olfactory impairment contributes to the prediction of cognitive decline. DESIGN Population-based longitudinal study. SETTING Beaver Dam, Wisconsin. PARTICIPANTS One thousand nine hundred twenty participants in the Epidemiology of Hearing Loss Study (mean age 66.9). MEASUREMENTS Olfaction was measured using the San Diego Odor Identification Test (SDOIT). Incident cognitive impairment was defined as a Mini-Mental State Examination (MMSE) score of less than 24 or reported diagnosis of dementia or Alzheimer's disease (AD) at follow-up in participants with a MMSE score of 24 or greater and no diagnosis of dementia or AD at baseline. RESULTS There was a significant association between olfactory impairment at baseline and 5-year incidence of cognitive impairment (odds ratio (OR)=6.62, 95% confidence interval (CI)=4.36-10.05). The association remained significant after adjusting for possible confounders (OR=3.72, 95% CI=2.31-5.99). The positive predictive value of the SDOIT was 15.9%, the negative predictive value was 97.2%, the sensitivity was 55.1%, and the specificity was 84.4% for 5-year incidence of cognitive impairment. CONCLUSION Olfactory impairment at baseline was strongly associated with 5-year incidence of cognitive impairment as measured using the MMSE. Odor identification testing may be useful in high-risk settings, but not in the general population, to identify patients at risk for cognitive decline.
Collapse
Affiliation(s)
- Carla R Schubert
- Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison, Wisconsin, USA.
| | | | | | | | | | | |
Collapse
|
36
|
Westervelt HJ, Bruce JM, Coon WG, Tremont G. Odor identification in mild cognitive impairment subtypes. J Clin Exp Neuropsychol 2008; 30:151-6. [DOI: 10.1080/13803390701287408] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Holly James Westervelt
- a Rhode Island Hospital, Department of Psychiatry , Providence, RI, USA
- b Brown Medical School, Department of Psychiatry and Human Behavior , Providence, RI, USA
| | - Jared M. Bruce
- a Rhode Island Hospital, Department of Psychiatry , Providence, RI, USA
- b Brown Medical School, Department of Psychiatry and Human Behavior , Providence, RI, USA
| | - William G. Coon
- a Rhode Island Hospital, Department of Psychiatry , Providence, RI, USA
| | - Geoffrey Tremont
- a Rhode Island Hospital, Department of Psychiatry , Providence, RI, USA
- b Brown Medical School, Department of Psychiatry and Human Behavior , Providence, RI, USA
| |
Collapse
|
37
|
|
38
|
Dulay MF, Gesteland RC, Shear PK, Ritchey PN, Frank RA. Assessment of the influence of cognition and cognitive processing speed on three tests of olfaction. J Clin Exp Neuropsychol 2007; 30:327-37. [PMID: 17852612 DOI: 10.1080/13803390701415892] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The extent to which measures of working memory, cognitive speed, and verbal retrieval are associated with performance on tests of olfaction was evaluated in a sample of 138 older adults. Structural equation modeling techniques indicated that verbal retrieval difficulties significantly affect performance on the University of Pennsylvania Smell Identification Test (UPSIT). Further, poor working memory and slow cognitive speed significantly affect performance on the UPSIT and the phenyl ethyl alcohol threshold test. The Sniff Magnitude Test was not influenced by any of the cognitive variables. Odor threshold and identification tasks may overestimate olfactory loss when cognitive impairment is not taken into account.
Collapse
Affiliation(s)
- Mario F Dulay
- Department of Neurosurgery, Baylor College of Medicine, 6560 Fannin, NB330, Houston, TX 77030, USA.
| | | | | | | | | |
Collapse
|
39
|
Demarquay G, Ryvlin P, Royet JP. Olfaction et pathologies neurologiques : revue de la littérature. Rev Neurol (Paris) 2007; 163:155-67. [PMID: 17351535 DOI: 10.1016/s0035-3787(07)90387-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Olfactory disorders are often misjudged and rarely rated in the clinical setting. They are nevertheless described in a wide range of neurological disorders, and their evaluation can be useful for diagnosis. Usually irreversible olfactory dysfunction is a well-known complication after head trauma. Severe changes in olfactory tests are observed in Parkinson's disease. Dysfunction is present at disease onset and evidenced with all behavioral tests. Regarding other parkinsonian syndromes, olfactory performances are severely impaired in Lewy body disease, less pronounced in multiple system atrophy and usually preserved in corticobasal degeneration. Olfactory deficits are an early feature in Alzheimer's disease and worsen with disease progression. Rarely reported by patients, they must be searched for with olfactory tests. Though epilepsy is mainly known for its olfactory hallucinatory disorders, alterations of olfactory abilities are also described, especially in mesial temporal epilepsy. Disorders of olfactory perception are finally reported in patients with multiple sclerosis and migraine. After a reminder of anatomical data on the olfactory system, and the different methods of testing used to rate olfactory performances, the current review focuses on the type of olfactory dysfunction and damaged brain areas of the olfactory system encountered in the main neurological diseases.
Collapse
Affiliation(s)
- G Demarquay
- Unité de Neurologie Fonctionnelle et d'Epileptologie, Hôpital Neurologique Pierre Wertheimer, Lyon.
| | | | | |
Collapse
|
40
|
Albers MW, Tabert MH, Devanand DP. Olfactory dysfunction as a predictor of neurodegenerative disease. Curr Neurol Neurosci Rep 2006; 6:379-86. [PMID: 16928347 DOI: 10.1007/s11910-996-0018-7] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Olfactory dysfunction is present in patients diagnosed with Alzheimer's disease or idiopathic Parkinson's disease and can differentiate each of these disorders from related disorders with similar clinical presentations. The pathologic hallmarks of each disease are present in brain regions involved in processing olfactory input. Both the olfactory functional deficits and the corroborating pathologic lesions are present in asymptomatic subjects with increased risk of developing these diseases. Preclinical detection of neurodegenerative diseases is necessary to control their devastating effects on individuals and societies. We address whether olfactory dysfunction can be used to assess risk for developing Alzheimer's disease or Parkinson's disease in asymptomatic individuals. We argue that further characterization and a deeper understanding of olfactory deficits in these neurodegenerative diseases at the molecular, cellular, and systems levels will augment our acumen for preclinical detection and elucidate pathogenic mechanisms to guide the development of new therapeutic modalities.
Collapse
Affiliation(s)
- Mark W Albers
- Department of Neurology, Columbia UniversityCollege of Physicians and Surgeons, 710 West 168th Street,New York, NY 10032, USA.
| | | | | |
Collapse
|
41
|
Royall DR, Gao JH, Kellogg DL. Insular Alzheimer's disease pathology as a cause of "age-related" autonomic dysfunction and mortality in the non-demented elderly. Med Hypotheses 2006; 67:747-58. [PMID: 16806725 DOI: 10.1016/j.mehy.2005.10.036] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2005] [Accepted: 10/28/2005] [Indexed: 10/24/2022]
Abstract
Only a few brain structures have been implicated in the autonomic control of blood pressure and heart rate. Among them are heteromodal association areas in the cortex, especially the insular cortex. Ischemic insular lesions have been associated with both cardiac arrhythmias and mortality. However, stroke may not be the only insular pathology with the potential to disrupt autonomic function. Alzheimer's disease (AD) is associated with both insular pathology and autonomic dysfunction. Alzheimer's dementia is merely the final stage of a pathological process that spans decades. Recent studies have demonstrated a hierarchichal sequence of AD pathology that includes the insular cortex. This may explain why AD has effects on BP and central autonomic cardio-regulatory functions. However, AD reaches the insular cortex at a "preclinical" stage in its development (i.e., before "dementia" can be diagnosed). Thus, AD pathology should also be considered as a possible explanation for autonomic morbidity and mortality in non-demented elderly persons. We hypothesize that autonomic dyscontrol, commonly seen in non-demented well elderly persons without significant cardiovascular disease (CVD), reflects subclinical stages of AD pathology affecting the insular cortex. If true, then preclinical AD pathology should be considered as a possible explanation for arrhythmia/fall related morbidity and mortality in non-demented elderly persons.
Collapse
Affiliation(s)
- Donald R Royall
- Department of Psychiatry, South Texas Veterans' Health System Audie L. Murphy Division GRECC and the University of Texas Health Science Center, 7703 Floyd Curl Dr., San Antonio, TX 78284-7792, United
| | | | | |
Collapse
|
42
|
Wilson RS, Arnold SE, Tang Y, Bennett DA. Odor identification and decline in different cognitive domains in old age. Neuroepidemiology 2005; 26:61-7. [PMID: 16352908 DOI: 10.1159/000090250] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The authors examined the association of odor identification with rate of decline in different cognitive systems. Participants are 481 older persons from the Rush Memory and Aging Project. At baseline, the Brief Smell Identification Test was administered. At annual intervals for up to 3 years, a battery of 19 cognitive tests was administered from which previously established composite measures of 5 cognitive domains were derived. In mixed-effects models adjusted for age, sex, and education, lower odor identification score was associated with lower function at baseline in each cognitive domain. Lower score was also associated with more rapid decline in perceptual speed (estimate=0.015, SE=0.006, p=0.013) and episodic memory (estimate=0.012, SE=0.006, p=0.030) but not with rate of decline in semantic memory, working memory, or visuospatial ability. Thus, on average, a person with a low odor identification score (6, 10th percentile) declined more than twice as rapidly in perceptual speed and episodic memory as a person with a high score (11, 90th percentile). Results were unchanged in subsequent analyses that controlled for cigarette smoking or clinically diagnosed stroke. The results indicate that impaired odor identification in old age is associated with impaired global cognition and more rapid decline in perceptual processing speed and episodic memory.
Collapse
Affiliation(s)
- Robert S Wilson
- Rush Alzheimer's Disease Center, Rush Institute for Healthy Aging, and Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612, USA.
| | | | | | | |
Collapse
|
43
|
Bonthius DJ, Solodkin A, Van Hoesen GW. Pathology of the Insular Cortex in Alzheimer Disease Depends on Cortical Architecture. J Neuropathol Exp Neurol 2005; 64:910-22. [PMID: 16215463 DOI: 10.1097/01.jnen.0000182983.87106.d1] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
The insular cortex plays important roles in a variety of regulatory mechanisms ranging from visceral control and sensation to covert judgments regarding inner well-being. The dementia of Alzheimer disease (AD) often includes behavioral dyscontrol and visceral dysfunction not observed in other diseases affecting cognition. This could be related to autonomic instability and to loss of the sense of self, and pathologic changes within the insula may play essential roles. The pattern of insular pathology of 17 patients with AD was examined and the severity of pathology was compared with that of the entorhinal cortex (EC), a region involved early in AD with reciprocal connections to the insula. Thioflavin S staining and Alz-50 immunostaining revealed that the insula carries a heavy burden of pathology in AD. Neurofibrillary tangles (NFTs) were largely confined to the deep layers of the cortex, whereas neuritic plaques (NPs) were distributed throughout the cellular layers and subcortical white matter. The density of NFTs, but not NPs, was highly correlated with the degree of EC pathology. However, NFTs were not seen in the insula until EC pathology reached a relatively advanced level. The density of insular NFTs varied according to architectonic type, with agranular cortex most affected, dysgranular cortex less affected, and granular cortex least affected. Thus, the insula is often involved in AD, and some of the behavioral abnormalities in AD may reflect insular pathology.
Collapse
Affiliation(s)
- Daniel J Bonthius
- Department of Pediatrics, University of Iowa College of Medicine, Iowa City, Iowa 52242, USA.
| | | | | |
Collapse
|
44
|
Economou A. Olfactory identification in elderly Greek people in relation to memory and attention measures. Arch Gerontol Geriatr 2003; 37:119-30. [PMID: 12888225 DOI: 10.1016/s0167-4943(03)00025-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The University of Pennsylvania Smell Identification Test (UPSIT) and the Cross-Cultural Smell Identification Test (CC-SIT) were administered to nondemented Greek participants ranging in age from 49 to 88 years together with tests of verbal memory from the Wechsler Memory Scale-3rd Edition (WMS-III). The test scores of the sample administered the CC-SIT were compared with the test scores of the 12 analogous UPSIT items of the sample administered the UPSIT. The percent of individuals correctly identifying each of the odorants of the UPSIT and CC-SIT is reported, together with means and standard deviations (S.D.) of the total smell scores. UPSIT performance in both the full test and the 12 analogous items was associated with WMS-III Logical Memory I performance after accounting for the effects of age, education and gender. CC-SIT performance was associated with gender, score on the Beck Depression Inventory-II and Logical Memory I performance. The study shows that olfactory identification is associated with verbal memory in nondemented individuals after accounting for demographic variables.
Collapse
Affiliation(s)
- Alexandra Economou
- Department of Psychology, School of Philosophy, The University of Athens, Panepistimiopolis, Athens, Greece.
| |
Collapse
|
45
|
Banks WA, Morley JE. Memories are made of this: recent advances in understanding cognitive impairments and dementia. J Gerontol A Biol Sci Med Sci 2003; 58:314-21. [PMID: 12663694 DOI: 10.1093/gerona/58.4.m314] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
46
|
|