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Wang X, Hu M, Xie Q, Geng C, Jin C, Ren W, Fan J, Ma T, Hu B. Amyloid β oligomers disrupt piriform cortical output via a serotonergic pathway. Neurobiol Aging 2022; 121:64-77. [DOI: 10.1016/j.neurobiolaging.2022.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 09/16/2022] [Accepted: 09/17/2022] [Indexed: 12/01/2022]
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Lehrer H, Dayan I, Elkayam K, Kfir A, Bierman U, Front L, Catz A, Aidinoff E. Responses to stimuli in the 'snoezelen' room in unresponsive wakefulness or in minimally responsive state. Brain Inj 2022; 36:1167-1175. [PMID: 35978560 DOI: 10.1080/02699052.2022.2110286] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
BACKGROUND Sensory stimulation in Snoezelen room increased responsiveness after brain injury and dementia. OBJECTIVE To explore the physiological and clinical effects of Snoezelen stimulation in persons with unresponsive wakefulness syndrome or minimally conscious state (UWS or MCS). DESIGN A comparative prospective observational cohort study. METHODS Ten patients with UWS and 25 in MCS were exposed to consecutive stimuli involving the 5 senses in a Snoezelen room. Heart rate (HR) and cerebral blood flow velocity (CBFV), and scores of the Loewenstein communication scale (LCS) were obtained before and during or after the stimuli. RESULTS The stimuli increased HR values and decreased left hemisphere CBFV values in patients with MCS (p < 0.05). Stimulation increased LCS scores (from 28.48 ± 6.55 to 31.13 ± 7.14; p < 0.001) in patients with MCS, but not in the UWS group. LCS gain correlated with HR and right hemisphere CBFV gains in patients with MCS (r = 0.439 and 0.636 respectively, p < 0.05). CONCLUSIONS Snoezelen stimulation induced immediate improvement in communication and physiological changes in patients with MSC, and had a minor physiological effect in patients with UWS. If additional studies support these findings, it will be possible to suggest that Snoezelen stimulation can affect arousal, and possibly improve functioning.
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Affiliation(s)
- Hiela Lehrer
- Departments of Intensive Care for Consciousness Rehabilitation and Spinal Rehabilitation, Loewenstein Rehabilitation Medical Center, Raanana, Israel
| | - Ilil Dayan
- Departments of Intensive Care for Consciousness Rehabilitation and Spinal Rehabilitation, Loewenstein Rehabilitation Medical Center, Raanana, Israel
| | - Keren Elkayam
- Departments of Intensive Care for Consciousness Rehabilitation and Spinal Rehabilitation, Loewenstein Rehabilitation Medical Center, Raanana, Israel
| | - Adi Kfir
- Departments of Intensive Care for Consciousness Rehabilitation and Spinal Rehabilitation, Loewenstein Rehabilitation Medical Center, Raanana, Israel
| | - Uri Bierman
- Departments of Intensive Care for Consciousness Rehabilitation and Spinal Rehabilitation, Loewenstein Rehabilitation Medical Center, Raanana, Israel
| | - Lilach Front
- Departments of Intensive Care for Consciousness Rehabilitation and Spinal Rehabilitation, Loewenstein Rehabilitation Medical Center, Raanana, Israel
| | - Amiram Catz
- Departments of Intensive Care for Consciousness Rehabilitation and Spinal Rehabilitation, Loewenstein Rehabilitation Medical Center, Raanana, Israel.,Sackler Faculty of Medicine, Rehabilitation Department, Tel Aviv University, Tel Aviv, Israel
| | - Elena Aidinoff
- Departments of Intensive Care for Consciousness Rehabilitation and Spinal Rehabilitation, Loewenstein Rehabilitation Medical Center, Raanana, Israel.,Sackler Faculty of Medicine, Rehabilitation Department, Tel Aviv University, Tel Aviv, Israel
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3
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Patel ZM, Holbrook EH, Turner JH, Adappa ND, Albers MW, Altundag A, Appenzeller S, Costanzo RM, Croy I, Davis GE, Dehgani-Mobaraki P, Doty RL, Duffy VB, Goldstein BJ, Gudis DA, Haehner A, Higgins TS, Hopkins C, Huart C, Hummel T, Jitaroon K, Kern RC, Khanwalkar AR, Kobayashi M, Kondo K, Lane AP, Lechner M, Leopold DA, Levy JM, Marmura MJ, Mclelland L, Miwa T, Moberg PJ, Mueller CA, Nigwekar SU, O'Brien EK, Paunescu TG, Pellegrino R, Philpott C, Pinto JM, Reiter ER, Roalf DR, Rowan NR, Schlosser RJ, Schwob J, Seiden AM, Smith TL, Soler ZM, Sowerby L, Tan BK, Thamboo A, Wrobel B, Yan CH. International consensus statement on allergy and rhinology: Olfaction. Int Forum Allergy Rhinol 2022; 12:327-680. [PMID: 35373533 DOI: 10.1002/alr.22929] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 01/01/2021] [Accepted: 11/19/2021] [Indexed: 12/11/2022]
Abstract
BACKGROUND The literature regarding clinical olfaction, olfactory loss, and olfactory dysfunction has expanded rapidly over the past two decades, with an exponential rise in the past year. There is substantial variability in the quality of this literature and a need to consolidate and critically review the evidence. It is with that aim that we have gathered experts from around the world to produce this International Consensus on Allergy and Rhinology: Olfaction (ICAR:O). METHODS Using previously described methodology, specific topics were developed relating to olfaction. Each topic was assigned a literature review, evidence-based review, or evidence-based review with recommendations format as dictated by available evidence and scope within the ICAR:O document. Following iterative reviews of each topic, the ICAR:O document was integrated and reviewed by all authors for final consensus. RESULTS The ICAR:O document reviews nearly 100 separate topics within the realm of olfaction, including diagnosis, epidemiology, disease burden, diagnosis, testing, etiology, treatment, and associated pathologies. CONCLUSION This critical review of the existing clinical olfaction literature provides much needed insight and clarity into the evaluation, diagnosis, and treatment of patients with olfactory dysfunction, while also clearly delineating gaps in our knowledge and evidence base that we should investigate further.
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Affiliation(s)
- Zara M Patel
- Otolaryngology, Stanford University School of Medicine, Stanford, California, USA
| | - Eric H Holbrook
- Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA
| | - Justin H Turner
- Otolaryngology, Vanderbilt School of Medicine, Nashville, Tennessee, USA
| | - Nithin D Adappa
- Otolaryngology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Mark W Albers
- Neurology, Harvard Medical School, Boston, Massachusetts, USA
| | - Aytug Altundag
- Otolaryngology, Biruni University School of Medicine, İstanbul, Turkey
| | - Simone Appenzeller
- Rheumatology, School of Medical Sciences, University of Campinas, São Paulo, Brazil
| | - Richard M Costanzo
- Physiology and Biophysics and Otolaryngology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
| | - Ilona Croy
- Psychology and Psychosomatic Medicine, TU Dresden, Dresden, Germany
| | - Greg E Davis
- Otolaryngology, Proliance Surgeons, Seattle and Puyallup, Washington, USA
| | - Puya Dehgani-Mobaraki
- Associazione Naso Sano, Umbria Regional Registry of Volunteer Activities, Corciano, Italy
| | - Richard L Doty
- Smell and Taste Center, Otolaryngology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Valerie B Duffy
- Allied Health Sciences, University of Connecticut, Storrs, Connecticut, USA
| | | | - David A Gudis
- Otolaryngology, Columbia University Irving Medical Center, New York, USA
| | - Antje Haehner
- Smell and Taste, Otolaryngology, TU Dresden, Dresden, Germany
| | - Thomas S Higgins
- Otolaryngology, University of Louisville School of Medicine, Louisville, Kentucky, USA
| | - Claire Hopkins
- Otolaryngology, Guy's and St. Thomas' Hospitals, London Bridge Hospital, London, UK
| | - Caroline Huart
- Otorhinolaryngology, Cliniques universitaires Saint-Luc, Institute of Neuroscience, Université catholgique de Louvain, Brussels, Belgium
| | - Thomas Hummel
- Smell and Taste, Otolaryngology, TU Dresden, Dresden, Germany
| | | | - Robert C Kern
- Otolaryngology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Ashoke R Khanwalkar
- Otolaryngology, Stanford University School of Medicine, Stanford, California, USA
| | - Masayoshi Kobayashi
- Otorhinolaryngology-Head and Neck Surgery, Mie University Graduate School of Medicine, Mie, Japan
| | - Kenji Kondo
- Otolaryngology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - Andrew P Lane
- Otolaryngology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Matt Lechner
- Otolaryngology, Barts Health and University College London, London, UK
| | - Donald A Leopold
- Otolaryngology, University of Vermont Medical Center, Burlington, Vermont, USA
| | - Joshua M Levy
- Otolaryngology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Michael J Marmura
- Neurology Thomas Jefferson University School of Medicine, Philadelphia, Pennsylvania, USA
| | - Lisha Mclelland
- Otolaryngology, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Takaki Miwa
- Otolaryngology, Kanazawa Medical University, Ishikawa, Japan
| | - Paul J Moberg
- Psychiatry, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | | | - Sagar U Nigwekar
- Division of Nephrology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Erin K O'Brien
- Otolaryngology, Mayo Clinic Rochester, Rochester, Minnesota, USA
| | - Teodor G Paunescu
- Division of Nephrology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | | | - Carl Philpott
- Otolaryngology, University of East Anglia, Norwich, UK
| | - Jayant M Pinto
- Otolaryngology, University of Chicago, Chicago, Illinois, USA
| | - Evan R Reiter
- Otolaryngology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
| | - David R Roalf
- Psychiatry, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Nicholas R Rowan
- Otolaryngology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Rodney J Schlosser
- Otolaryngology, Medical University of South Carolina, Mt Pleasant, South Carolina, USA
| | - James Schwob
- Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Allen M Seiden
- Otolaryngology, University of Cincinnati School of Medicine, Cincinnati, Ohio, USA
| | - Timothy L Smith
- Otolaryngology, Oregon Health and Sciences University, Portland, Oregon, USA
| | - Zachary M Soler
- Otolaryngology, Medical University of South Carolina, Mt Pleasant, South Carolina, USA
| | - Leigh Sowerby
- Otolaryngology, University of Western Ontario, London, Ontario, Canada
| | - Bruce K Tan
- Otolaryngology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Andrew Thamboo
- Otolaryngology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Bozena Wrobel
- Otolaryngology, Keck School of Medicine, USC, Los Angeles, California, USA
| | - Carol H Yan
- Otolaryngology, School of Medicine, UCSD, La Jolla, California, USA
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Influence of Intragastric Administration of Traditional Japanese Medicine, Ninjin'Yoeito, on Cerebral Blood Flow via Muscarinic Acetylcholine Receptors. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2021; 2021:9930023. [PMID: 34408784 PMCID: PMC8367494 DOI: 10.1155/2021/9930023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 06/15/2021] [Accepted: 07/01/2021] [Indexed: 11/22/2022]
Abstract
Ninjin'yoeito (NYT) is a traditional medicine that has been used for mitigating physical frailty, such as fatigue and anorexia, as well as for cognitive dysfunction. Maintenance of adequate cerebral blood flow (CBF) is important for preventing cognitive dysfunction. The present study aimed to examine the effect of NYT on CBF. Male C57BL/6 J mice were anesthetized with urethane and were artificially ventilated. We measured CBF in the neocortex with laser-speckle contrast imaging for 10 min before administration and 60 min after administration. We administered NYT solution (0.25, 0.5, 1, and 2 g/kg) or vehicle (distilled water; DW) over 5 min via an intragastric catheter. We surgically transected the vagus nerve to investigate its contribution as a neural pathway and intraperitoneally injected atropine to block muscarinic acetylcholine receptors. Finally, we tested the CBF response to cutaneous brushing stimulation applied to the left hind paw (30 sec). CBF decreased after DW administration, starting from 30 min onward, whereas CBF did not change after NYT. The averaged CBF change following DW administration differed from that following NYT (1 g/kg) but not from those following the other doses of NYT. Arterial pressure was not affected by either solution. CBF after NYT (1 g/kg) was not affected by vagotomy but was lower following additional atropine. In response to brushing stimulation, CBF in the right (contralateral) parietal cortex increased. The magnitude of CBF increase following NYT was greater than that following DW. These results suggest that NYT prevents CBF decrease via cholinergic activation independent of vagal activity and enhances the CBF response to somatosensory stimulation.
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Kjelvik G, Evensmoen HR, Hummel T, Engedal K, Selbæk G, Saltvedt I, Håberg AK. The Human Brain Representation of Odor Identification in Amnestic Mild Cognitive Impairment and Alzheimer's Dementia of Mild Degree. Front Neurol 2021; 11:607566. [PMID: 33519686 PMCID: PMC7838677 DOI: 10.3389/fneur.2020.607566] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 12/02/2020] [Indexed: 11/13/2022] Open
Abstract
Background: Odor identification (OI) ability is a suggested early biomarker of Alzheimer's disease. In this study, we investigated brain activity within the brain's olfactory network associated with OI in patients with amnestic mild cognitive impairment (aMCI) and mild Alzheimer's dementia (mAD) to uncover the neuronal basis of this impairment. Materials and Methods: Patients with aMCI (n = 11) or mAD (n = 6) and 28 healthy older adults underwent OI functional MRI (fMRI) at 3T, OI, odor discrimination, and cognitive tests and apolipoprotein-e4 (APOE4) genotyping. Eleven patients had cerebrospinal fluid (CSF) analyzed. Those with aMCI were followed for 2 years to examine conversion to dementia. Results: The aMCI/mAD group performed significantly worse on all OI tests and the odor discrimination test compared to controls. The aMCI/mAD group had reduced activation in the right anterior piriform cortex compared to the controls during OI fMRI [Gaussian random field (GRF) corrected cluster threshold, p < 0.05]. This group difference remained after correcting for age, sex education, and brain parenchymal fraction. This difference in piriform activity was driven primarily by differences in odor discrimination ability and to a lesser extent by OI ability. There was no group by odor discrimination/identification score interaction on brain activity. Across both groups, only odor discrimination score was significantly associated with brain activity located to the right piriform cortex. Brain activity during OI was not associated with Mini Mental Status Examination scores. At the group level, the aMCI/mAD group activated only the anterior insula, while the control group had significant activation within all regions of the olfactory network during OI fMRI. There was no association between brain activity during OI fMRI and total beta-amyloid levels in the CSF in the aMCI/mAD group. Conclusion: The OI impairment in aMCI/mAD patients is associated with significantly reduced activity in the piriform cortex compared to controls. Activation of downstream regions within the olfactory network is also significantly affected in the aMCI/mAD group, except the anterior insula, which is impinged late in the course of Alzheimer's disease. OI tests thus reflect Alzheimer's disease pathology in olfactory brain structures.
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Affiliation(s)
- Grete Kjelvik
- Norwegian National Advisory Unit on Ageing and Health (Ageing and Health), Tønsberg, Norway.,Department of Radiology and Nuclear Medicine, St. Olavs Hospital (Norwegian National Advisory Unit for Functional Magnetic Resonance Imaging), University Hospital of Trondheim, Trondheim, Norway
| | - Hallvard R Evensmoen
- Department of Radiology and Nuclear Medicine, St. Olavs Hospital (Norwegian National Advisory Unit for Functional Magnetic Resonance Imaging), University Hospital of Trondheim, Trondheim, Norway.,Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Trondheim, Norway
| | - Thomas Hummel
- Smell and Taste Clinic, Department of Otorhinolaryngology, Technische Universität Dresden, Dresden, Germany
| | - Knut Engedal
- Norwegian National Advisory Unit on Ageing and Health (Ageing and Health), Tønsberg, Norway
| | - Geir Selbæk
- Norwegian National Advisory Unit on Ageing and Health (Ageing and Health), Tønsberg, Norway.,Institute of Clinical Medicine, University of Oslo, Oslo, Norway.,Department of Geriatric Medicine, Oslo University Hospital, Oslo, Norway
| | - Ingvild Saltvedt
- Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Geriatrics, Clinic of Medicine, St. Olavs Hospital, University Hospital of Trondheim, Trondheim, Norway
| | - Asta K Håberg
- Department of Radiology and Nuclear Medicine, St. Olavs Hospital (Norwegian National Advisory Unit for Functional Magnetic Resonance Imaging), University Hospital of Trondheim, Trondheim, Norway.,Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Trondheim, Norway
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6
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Odorant-induced brain activation as a function of normal aging and Alzheimer's disease: A preliminary study. Behav Brain Res 2021; 402:113078. [PMID: 33359846 DOI: 10.1016/j.bbr.2020.113078] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 12/10/2020] [Accepted: 12/14/2020] [Indexed: 11/23/2022]
Abstract
Olfactory dysfunction consistently occurs in patients with Alzheimer's disease (AD), beyond the mild and gradual decline in olfactory ability found in normal aging. This dysfunction begins early in the disease course, typically before clinical diagnosis, and progresses with disease severity. While odor identification and detection deficits clearly differentiate AD from controls, there remains uncertainty as to whether these are determined by olfactory threshold. The purpose of the current preliminary fMRI study was to examine the neural correlates of olfactory processing in healthy young and old adults and compare them with AD patients. We also explored the interplay between age and disease-related psychophysical olfactory declines and odorant-induced brain activation. Results indicated AD patients had decreased odor detection task-related signal in all regions of the primary olfactory cortex, with activity in the entorhinal cortex best differentiating the groups. Moderated-mediation analyses on neuro-psychophysical relationships found that increased brain activation in the entorhinal cortex moderated the negative effect of disease-related threshold changes on olfactory detection. Therefore, even in the face of higher (worse) olfactory thresholds, older adults and AD patients compensated for this effect with increased brain activation in a primary olfactory brain region. This was the case for odor detection but not odor identification. fMRI activation induced by an olfactory detection task may eventually be useful in improving early discovery of AD and may, eventually, facilitate early treatment interventions in subjects at risk for AD.
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7
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Bathini P, Brai E, Auber LA. Olfactory dysfunction in the pathophysiological continuum of dementia. Ageing Res Rev 2019; 55:100956. [PMID: 31479764 DOI: 10.1016/j.arr.2019.100956] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 07/29/2019] [Accepted: 08/26/2019] [Indexed: 12/21/2022]
Abstract
Sensory capacities like smell, taste, hearing, vision decline with aging, but increasing evidence show that sensory dysfunctions are one of the early signs diagnosing the conversion from physiological to pathological brain state. Smell loss represents the best characterized sense in clinical practice and is considered as one of the first preclinical signs of Alzheimer's and Parkinson's disease, occurring a decade or more before the onset of cognitive and motor symptoms. Despite the numerous scientific reports and the adoption in clinical practice, the etiology of sensory damage as prodromal of dementia remains largely unexplored and more studies are needed to resolve the mechanisms underlying sensory network dysfunction. Although both cognitive and sensory domains are progressively affected, loss of sensory experience in early stages plays a major role in reducing the autonomy of demented people in their daily tasks or even possibly contributing to their cognitive decline. Interestingly, the chemosensory circuitry is devoid of a blood brain barrier, representing a vulnerable port of entry for neurotoxic species that can spread to the brain. Furthermore, the exposure of the olfactory system to the external environment make it more susceptible to mechanical injury and trauma, which can cause degenerative neuroinflammation. In this review, we will summarize several findings about chemosensory impairment signing the conversion from healthy to pathological brain aging and we will try to connect those observations to the promising research linking environmental influences to sporadic dementia. The scientific body of knowledge will support the use of chemosensory diagnostics in the presymptomatic stages of AD and other biomarkers with the scope of finding treatment strategies before the onset of the disease.
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Affiliation(s)
- Praveen Bathini
- Department of Medicine, University of Fribourg, Fribourg, Switzerland
| | - Emanuele Brai
- VIB-KU Leuven Center for Brain & Disease Research, Laboratory for the Research of Neurodegenerative Diseases, Leuven, Belgium
| | - Lavinia Alberi Auber
- Department of Medicine, University of Fribourg, Fribourg, Switzerland; Swiss Integrative Center of Human Health, Fribourg, Switzerland.
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Adlimoghaddam A, Snow WM, Stortz G, Perez C, Djordjevic J, Goertzen AL, Ko JH, Albensi BC. Regional hypometabolism in the 3xTg mouse model of Alzheimer's disease. Neurobiol Dis 2019; 127:264-277. [PMID: 30878533 DOI: 10.1016/j.nbd.2019.03.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 02/22/2019] [Accepted: 03/12/2019] [Indexed: 12/28/2022] Open
Abstract
Alzheimer's disease (AD) is a progressive age-related neurodegenerative disease. Although neurofibrillary tangles and amyloid beta are classic hallmarks of AD, the earliest deficits in AD progression may be caused by unknown factors. One suspected factor has to do with brain energy metabolism. To investigate this factor, brain metabolic activity in 3xTg-AD mice and age-matched controls were measured with FDG-PET. Significant hypometabolic changes (p < .01) in brain metabolism were detected in the cortical piriform and insular regions of AD brains relative to controls. These regions are associated with olfaction, which is a potential clinical marker for AD progression as well as neurogenesis. The activity of the terminal component of the mitochondrial respiratory chain (complex IV) and the expression of complex I-V were significantly decreased (p < .05), suggesting that impaired metabolic activity coupled with impaired oxidative phosphorylation leads to decreased mitochondrial bioenergetics and subsequent Neurodegeneration. Although there is an association between neuroinflammatory pathological markers (microglial) and hypometabolism in AD, there was no association found between neuropathological (Aβ, tau, and astrocytes) and functional changes in AD sensitive brain regions, also suggesting that brain hypometabolism occurs prior to AD pathology. Therefore, targeting metabolic mechanisms in cortical piriform and insular regions at early stages may be a promising approach for preventing, slowing, and/or blocking the onset of AD and preserving neurogenesis.
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Affiliation(s)
- Aida Adlimoghaddam
- St. Boniface Hospital Research, Canada; Dept. of Pharmacology & Therapeutics, University of Manitoba, Canada.
| | | | | | - Claudia Perez
- St. Boniface Hospital Research, Canada; Dept. of Pharmacology & Therapeutics, University of Manitoba, Canada
| | - Jelena Djordjevic
- St. Boniface Hospital Research, Canada; Dept. of Pharmacology & Therapeutics, University of Manitoba, Canada
| | | | - Ji Hyun Ko
- Dept. of Human Anatomy and Cell Science, University of Manitoba, Canada; Health Sciences Centre, Canada
| | - Benedict C Albensi
- St. Boniface Hospital Research, Canada; Dept. of Pharmacology & Therapeutics, University of Manitoba, Canada.
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Doty RL, Hawkes CH. Chemosensory dysfunction in neurodegenerative diseases. HANDBOOK OF CLINICAL NEUROLOGY 2019; 164:325-360. [PMID: 31604557 DOI: 10.1016/b978-0-444-63855-7.00020-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A number of neurodegenerative diseases are accompanied by disordered smell function. The degree of dysfunction can vary among different diseases, such that olfactory testing can aid in differentiating, for example, Alzheimer's disease (AD) from major affective disorder and Parkinson's disease (PD) from progressive supranuclear palsy. Unfortunately, altered smell function often goes unrecognized by patients and physicians alike until formal testing is undertaken. Such testing uniquely probes brain regions not commonly examined in physical examinations and can identify, in some cases, patients who are already in the "preclinical" stage of disease. Awareness of this fact is one reason why the Quality Standards Committee of the American Academy of Neurology has designated smell dysfunction as one of the key diagnostic criteria for PD. The same recommendation has been made by the Movement Disorder Society for both the diagnosis of PD and identification of prodromal PD. Similar suggestions are proposed to include olfactory dysfunction as an additional research criterion for the diagnosis of AD. Although taste impairment, i.e., altered sweet, sour, bitter, salty, and umami perception, has also been demonstrated in some disorders, taste has received much less scientific attention than smell. In this review, we assess what is known about the smell and taste disorders of a wide range of neurodegenerative diseases and describe studies seeking to understand their pathologic underpinnings.
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Affiliation(s)
- Richard L Doty
- Smell and Taste Center and Department of Otorhinolaryngology: Head and Neck Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States.
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10
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Silva MDME, Mercer PBS, Witt MCZ, Pessoa RR. Olfactory dysfunction in Alzheimer's disease Systematic review and meta-analysis. Dement Neuropsychol 2018; 12:123-132. [PMID: 29988355 PMCID: PMC6022986 DOI: 10.1590/1980-57642018dn12-020004] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Alzheimer’s disease (AD), a neurodegenerative condition, is one of the most prevalent kinds of dementia, whose frequency doubles for every 5 years of age in elderly.
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Affiliation(s)
| | | | | | - Renata Ramina Pessoa
- MD. Hospital da Cruz Vermelha Filial do Paraná. Neurology Department. Curitiba, PR, Brazil
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11
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Olfactory identification in subjective cognitive decline and mild cognitive impairment: Association with tau but not amyloid positron emission tomography. ALZHEIMER'S & DEMENTIA: DIAGNOSIS, ASSESSMENT & DISEASE MONITORING 2017; 9:57-66. [PMID: 29159268 PMCID: PMC5675709 DOI: 10.1016/j.dadm.2017.09.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Introduction We investigated the association between olfactory identification and Alzheimer's disease biomarkers, including amyloid, tau, and neurodegeneration. Methods Thirty-four older adults, including 19 cognitively normal (CN), 10 subjective cognitive decline (SCD), and 5 mild cognitive impairment, underwent amyloid positron emission tomography, magnetic resonance imaging, and the University of Pennsylvania Smell Identification Test (UPSIT). Twenty-six also underwent tau positron emission tomography. Associations between the UPSIT and regionally sampled amyloid, tau, and temporal atrophy were evaluated. Voxel-wise regression models were also utilized. Analyses were conducted with the full sample and only CN/SCD. Results Lower UPSIT scores were associated with increased temporal and parietal tau burden in regional and voxel-wise analyses in the full sample and in CN and SCD only. Temporal lobe atrophy was associated with lower UPSIT score. Amyloid was not associated with the UPSIT. Discussion Impairment on the UPSIT may be a good marker for tau and neurodegeneration in preclinical or prodromal Alzheimer's disease.
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12
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Mazzola L, Royet JP, Catenoix H, Montavont A, Isnard J, Mauguière F. Gustatory and olfactory responses to stimulation of the human insula. Ann Neurol 2017; 82:360-370. [DOI: 10.1002/ana.25010] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Revised: 08/04/2017] [Accepted: 08/04/2017] [Indexed: 12/21/2022]
Affiliation(s)
- Laure Mazzola
- Neurology Department; University Hospital; Saint-Étienne
- Central Integration of Pain Team, Lyon Neuroscience Research Center, National Institute of Health and Medical Research Unit 1028; National Center for Scientific Research Mixed Unit of Research 5292; Lyon
- Jean Monnet University; Saint-Étienne
| | - Jean-Pierre Royet
- Olfaction: From Coding to Memory Team, Lyon Neuroscience Research Center, National Institute of Health and Medical Research Unit 1028, National Center for Scientific Research Mixed Unit of Research 5292; University of Lyon; Lyon
- Claude Bernard University Lyon 1; University of Lyon; Lyon
| | - Hélène Catenoix
- Functional Neurology and Epilepsy Department, Neurological Hospital; Civil Hospices of Lyon; Lyon France
| | - Alexandra Montavont
- Functional Neurology and Epilepsy Department, Neurological Hospital; Civil Hospices of Lyon; Lyon France
| | - Jean Isnard
- Central Integration of Pain Team, Lyon Neuroscience Research Center, National Institute of Health and Medical Research Unit 1028; National Center for Scientific Research Mixed Unit of Research 5292; Lyon
- Functional Neurology and Epilepsy Department, Neurological Hospital; Civil Hospices of Lyon; Lyon France
| | - François Mauguière
- Central Integration of Pain Team, Lyon Neuroscience Research Center, National Institute of Health and Medical Research Unit 1028; National Center for Scientific Research Mixed Unit of Research 5292; Lyon
- Claude Bernard University Lyon 1; University of Lyon; Lyon
- Functional Neurology and Epilepsy Department, Neurological Hospital; Civil Hospices of Lyon; Lyon France
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Lafaille-Magnan ME, Poirier J, Etienne P, Tremblay-Mercier J, Frenette J, Rosa-Neto P, Breitner JCS. Odor identification as a biomarker of preclinical AD in older adults at risk. Neurology 2017; 89:327-335. [PMID: 28659431 PMCID: PMC5574678 DOI: 10.1212/wnl.0000000000004159] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 04/28/2017] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To assess odor identification (OI) as an indicator of presymptomatic Alzheimer disease (AD) pathogenesis in cognitively normal aging individuals at increased risk of AD dementia. METHODS In 274 members of the PREVENT-AD cohort of healthy aging persons with a parental or multiple-sibling history of AD dementia, we assessed the cross-sectional association of OI with potential indicators of presymptomatic AD. Some 101 participants donated CSF, thus enabling assessment of AD pathology with the biomarkers total tau (t-tau), phospho-tau (P181-tau), and their ratios with β-amyloid (Aβ1-42). Adjusted analyses considered age, cognition, APOE ε4 status, education, and sex as covariates. We measured OI using the University of Pennsylvania Smell Identification Test and cognitive performance using the Repeatable Battery for Assessment of Neuropsychological Status. Standard kits provided assays of the AD biomarkers. Analyses used robust-fit linear regression models. RESULTS Reduced OI was associated with lower cognitive score and older age, as well as increased ratios of CSF t-tau and P181-tau to Aβ1-42 (all p < 0.02). However, the observed associations of OI with age and cognition were unapparent in adjusted models that restricted observations to CSF donors and included AD biomarkers. OI showed little association with CSF Aβ1-42 alone except in APOE ε4 carriers having lowest-quartile Aβ1-42 levels. CONCLUSIONS These findings from healthy high-risk older individuals suggest that OI reflects degree of preclinical AD pathology, while its relationships with age and cognition result from the association of these latter variables with such pathology. Diminished OI may be a practical and affordable biomarker of AD pathology.
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Affiliation(s)
- Marie-Elyse Lafaille-Magnan
- From the Centre for Studies on Prevention of AD (M.-E.L.-M., J.P., P.E., J.T.-M., J.F., P.R.-N., J.C.S.B.) and McGill Centre for Studies in Aging (P.R.-N.), Douglas Mental Health University Institute, McGill University, Faculty of Medicine, Montreal, Quebec, Canada.
| | - Judes Poirier
- From the Centre for Studies on Prevention of AD (M.-E.L.-M., J.P., P.E., J.T.-M., J.F., P.R.-N., J.C.S.B.) and McGill Centre for Studies in Aging (P.R.-N.), Douglas Mental Health University Institute, McGill University, Faculty of Medicine, Montreal, Quebec, Canada
| | - Pierre Etienne
- From the Centre for Studies on Prevention of AD (M.-E.L.-M., J.P., P.E., J.T.-M., J.F., P.R.-N., J.C.S.B.) and McGill Centre for Studies in Aging (P.R.-N.), Douglas Mental Health University Institute, McGill University, Faculty of Medicine, Montreal, Quebec, Canada
| | - Jennifer Tremblay-Mercier
- From the Centre for Studies on Prevention of AD (M.-E.L.-M., J.P., P.E., J.T.-M., J.F., P.R.-N., J.C.S.B.) and McGill Centre for Studies in Aging (P.R.-N.), Douglas Mental Health University Institute, McGill University, Faculty of Medicine, Montreal, Quebec, Canada
| | - Joanne Frenette
- From the Centre for Studies on Prevention of AD (M.-E.L.-M., J.P., P.E., J.T.-M., J.F., P.R.-N., J.C.S.B.) and McGill Centre for Studies in Aging (P.R.-N.), Douglas Mental Health University Institute, McGill University, Faculty of Medicine, Montreal, Quebec, Canada
| | - Pedro Rosa-Neto
- From the Centre for Studies on Prevention of AD (M.-E.L.-M., J.P., P.E., J.T.-M., J.F., P.R.-N., J.C.S.B.) and McGill Centre for Studies in Aging (P.R.-N.), Douglas Mental Health University Institute, McGill University, Faculty of Medicine, Montreal, Quebec, Canada
| | - John C S Breitner
- From the Centre for Studies on Prevention of AD (M.-E.L.-M., J.P., P.E., J.T.-M., J.F., P.R.-N., J.C.S.B.) and McGill Centre for Studies in Aging (P.R.-N.), Douglas Mental Health University Institute, McGill University, Faculty of Medicine, Montreal, Quebec, Canada
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14
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Passler JS, Doty RL, Dolske MC, St. Louis PG, Basignani C, Pepe JW, Bushnev S. Olfactory ability in normal pressure hydrocephalus as compared to Alzheimer's disease and healthy controls. J Neurol Sci 2017; 372:217-219. [DOI: 10.1016/j.jns.2016.11.049] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 11/14/2016] [Accepted: 11/21/2016] [Indexed: 10/20/2022]
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15
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Velayudhan L, Gasper A, Pritchard M, Baillon S, Messer C, Proitsi P. Pattern of Smell Identification Impairment in Alzheimer's Disease. J Alzheimers Dis 2016; 46:381-7. [PMID: 25757648 DOI: 10.3233/jad-142838] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Olfactory dysfunction in general, and impaired odor identification in particular, have been reported in Alzheimer's disease (AD). Olfactory testing may be a useful diagnostic aid for AD, but the types of odor most commonly affected need to be identified. This study aimed to determine pattern and types of odor affected in AD with the goal of improving clinical applicability. 54 outpatients with mild to moderate AD and 40 age and gender-matched non-demented controls (NDC) were tested using British version of University of Pennsylvania Smell Identification Test (UPSIT; Sensonics, Inc., Haddon Heights, NJ) and data analyzed to identify an optimal subset of UPSIT to best differentiate AD patients from controls. AD subjects had significantly lower UPSIT total scores than NDC. Random Forest with backward elimination identified 12 UPSIT items which accurately differentiated AD patients compared to controls (sensitivity, 0.89 and specificity, 0.83, positive predictive value of 0.889, and negative predictive value of 0.833). The 12 smell items found to be most affected in AD subjects reflects important attributes such as safety and food, known to be affected in people with AD and that has the potential to impair activities of daily living. The 12 items of British UPSIT most affected in AD subjects provides a potential brief scale for early detection of AD in clinical settings. Independent replication is needed to validate these findings.
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Affiliation(s)
- Latha Velayudhan
- Department of Health Sciences, Psychiatry for the Elderly, University of Leicester, Leicester, UK
| | - Amy Gasper
- Department of Health Sciences, Psychiatry for the Elderly, University of Leicester, Leicester, UK
| | - Megan Pritchard
- King's College London, Institute of Psychiatry, Psychology & Neuroscience, London, UK
| | - Sarah Baillon
- Department of Health Sciences, Psychiatry for the Elderly, University of Leicester, Leicester, UK
| | - Charlotte Messer
- Mental Health Services for Older People, Leicestershire Partnership NHS Trust, Leicester, UK
| | - Petroula Proitsi
- King's College London, Institute of Psychiatry, Psychology & Neuroscience, London, UK
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16
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Abstract
Alzheimer's disease (AD) is a common neurodegenerative disorder with the earliest clinical symptom of olfactory dysfunction, which is a potential clinical marker for AD severity and progression. However, many questions remain unanswered. This article reviews relevant research on olfactory dysfunction in AD and evaluates the predictive value of olfactory dysfunction for the epidemiological, pathophysiological, and clinical features of AD, as well as for the conversion of cognitive impairment to AD. We summarize problems of existing studies and provide a useful reference for further studies in AD olfactory dysfunction and for clinical applications of olfactory testing.
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Affiliation(s)
- Yong-Ming Zou
- Department of Neurology, Tianjin Huanhu Hospital, Tianjin, People's Republic of China
| | - Da Lu
- Department of Neurology, Tianjin Huanhu Hospital, Tianjin, People's Republic of China
| | - Li-Ping Liu
- Department of Neurology, Tianjin Huanhu Hospital, Tianjin, People's Republic of China
| | - Hui-Hong Zhang
- Department of Neurology, Tianjin Huanhu Hospital, Tianjin, People's Republic of China
| | - Yu-Ying Zhou
- Department of Neurology, Tianjin Huanhu Hospital, Tianjin, People's Republic of China
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17
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Saiz-Sanchez D, Flores-Cuadrado A, Ubeda-Bañon I, de la Rosa-Prieto C, Martinez-Marcos A. Interneurons in the human olfactory system in Alzheimer's disease. Exp Neurol 2015; 276:13-21. [PMID: 26616239 DOI: 10.1016/j.expneurol.2015.11.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 11/12/2015] [Accepted: 11/21/2015] [Indexed: 01/09/2023]
Abstract
The principal olfactory structures display Alzheimer's disease (AD) related pathology at early stages of the disease. Consequently, olfactory deficits are among the earliest symptoms. Reliable olfactory tests for accurate clinical diagnosis are rarely made. In addition, neuropathological analysis postmortem of olfactory structures is often not made. Therefore, the relationship between the clinical features and the underlying pathology is poorly defined. Traditionally, research into Alzheimer's disease has focused on the degeneration of cortical temporal projection neurons and cholinergic neurons. Recent evidence has demonstrated the neurodegeneration of interneuron populations in AD. This review provides an updated overview of the pathological involvement of interneuron populations in the human olfactory system in Alzheimer's disease.
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Affiliation(s)
- Daniel Saiz-Sanchez
- Laboratorio de Neuroplasticidad y Neurodegeneración, Facultad de Medicina de Ciudad Real, Centro Regional de Investigaciones Biomédicas, Universidad de Castilla-La Mancha, 13005 Ciudad Real, Spain
| | - Alicia Flores-Cuadrado
- Laboratorio de Neuroplasticidad y Neurodegeneración, Facultad de Medicina de Ciudad Real, Centro Regional de Investigaciones Biomédicas, Universidad de Castilla-La Mancha, 13005 Ciudad Real, Spain
| | - Isabel Ubeda-Bañon
- Laboratorio de Neuroplasticidad y Neurodegeneración, Facultad de Medicina de Ciudad Real, Centro Regional de Investigaciones Biomédicas, Universidad de Castilla-La Mancha, 13005 Ciudad Real, Spain
| | - Carlos de la Rosa-Prieto
- Laboratorio de Neuroplasticidad y Neurodegeneración, Facultad de Medicina de Ciudad Real, Centro Regional de Investigaciones Biomédicas, Universidad de Castilla-La Mancha, 13005 Ciudad Real, Spain
| | - Alino Martinez-Marcos
- Laboratorio de Neuroplasticidad y Neurodegeneración, Facultad de Medicina de Ciudad Real, Centro Regional de Investigaciones Biomédicas, Universidad de Castilla-La Mancha, 13005 Ciudad Real, Spain.
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18
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Daulatzai MA. Olfactory dysfunction: its early temporal relationship and neural correlates in the pathogenesis of Alzheimer’s disease. J Neural Transm (Vienna) 2015; 122:1475-97. [DOI: 10.1007/s00702-015-1404-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 04/29/2015] [Indexed: 12/18/2022]
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19
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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: 44] [Impact Index Per Article: 4.4] [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.
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20
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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.
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21
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Cai Y, Xue ZQ, Zhang XM, Li MB, Wang H, Luo XG, Cai H, Yan XX. An age-related axon terminal pathology around the first olfactory relay that involves amyloidogenic protein overexpression without plaque formation. Neuroscience 2012; 215:160-73. [DOI: 10.1016/j.neuroscience.2012.04.043] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Revised: 04/14/2012] [Accepted: 04/18/2012] [Indexed: 01/08/2023]
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22
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Sun GH, Raji CA, Maceachern MP, Burke JF. Olfactory identification testing as a predictor of the development of Alzheimer's dementia: a systematic review. Laryngoscope 2012; 122:1455-62. [PMID: 22552846 DOI: 10.1002/lary.23365] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Revised: 03/23/2012] [Accepted: 03/28/2012] [Indexed: 12/21/2022]
Abstract
OBJECTIVES/HYPOTHESIS To evaluate the utility of olfactory identification tests as prognostic instruments for Alzheimer's dementia (AD). STUDY DESIGN Systematic review. METHODS In accordance with PRISMA guidelines, PubMed and Ovid MEDLINE, EMBASE, ISI Web of Science, PsycINFO, the Cochrane Database of Systematic Reviews, and the Cochrane Central Register of Controlled Trials were searched to determine the quality and quantity of longitudinal and cross-sectional research on this topic. RESULTS Two prospective longitudinal cohort studies and 30 cross-sectional studies met inclusion criteria. The prospective longitudinal studies evaluated subjects with or without mild cognitive impairment (MCI) while also using olfactory identification testing as part of a neurocognitive evaluation. The first study reported an increased risk of later onset of AD in subjects with baseline hyposmia, whereas the second study suggested a possible relationship between decreased olfaction in participants with MCI and conversion to AD but was inconclusive due to low follow-up rates. Wide variability in the type of olfactory identification test used and the reporting of results precluded meta-analysis. The cross-sectional studies demonstrated a positive association between poorer performance on olfactory identification testing and AD. CONCLUSIONS Although there is evidence suggesting an association between decreased olfaction and AD, rigorously designed longitudinal cohort studies are necessary to clarify the value of olfactory identification testing in predicting the onset of AD.
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Affiliation(s)
- Gordon H Sun
- Robert Wood Johnson Foundation Clinical Scholars, University of Michigan, Ann Arbor, Michigan, USA.
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23
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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
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Li W, Howard JD, Gottfried JA. Disruption of odour quality coding in piriform cortex mediates olfactory deficits in Alzheimer's disease. Brain 2010; 133:2714-26. [PMID: 20724290 DOI: 10.1093/brain/awq209] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Patients with early-stage Alzheimer's disease exhibit perceptual deficits in odour identification, often before the appearance of overt memory loss. This impairment coincides with the initial accumulation of pathological lesions in limbic olfactory brain regions. Although these data imply that odour stimuli may be effectively used as biological probes of limbic dysfunction, the precise neural mechanisms underlying the olfactory deficits in early Alzheimer's disease remain poorly understood. In the current study, we combined functional magnetic resonance imaging with an olfactory cross-adaptation paradigm to test the hypothesis that perceptual codes of odour quality in posterior piriform cortex are degraded in patients with Alzheimer's disease. In elderly control subjects, sequential presentation of qualitatively similar (versus qualitatively different) odourant pairs elicited cross-adapting responses in posterior piriform cortex, in accord with the pattern observed in healthy young adults. However, this profile was significantly blunted in patients with Alzheimer's disease, reflecting a functional disruption of odour quality coding in this olfactory brain area. These results highlight the potential of olfactory functional magnetic resonance imaging as a non-invasive bioassay of limbic functional integrity, and suggest that such an index could possibly aid in the early diagnosis of Alzheimer's disease. Furthermore, as a putative lesion model of odour quality processing in the human brain, our study suggests a causal role of posterior piriform cortex in differentiating olfactory objects.
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Affiliation(s)
- Wen Li
- Department of Psychology, University of Wisconsin-Madison, 1202 W. Johnson Street, Madison, WI 53706, USA.
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25
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Wang J, Eslinger PJ, Doty RL, Zimmerman EK, Grunfeld R, Sun X, Meadowcroft MD, Connor JR, Price JL, Smith MB, Yang QX. Olfactory deficit detected by fMRI in early Alzheimer's disease. Brain Res 2010; 1357:184-94. [PMID: 20709038 DOI: 10.1016/j.brainres.2010.08.018] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2009] [Revised: 08/05/2010] [Accepted: 08/06/2010] [Indexed: 11/17/2022]
Abstract
Alzheimer's disease (AD) is accompanied by smell dysfunction, as measured by psychophysical tests. Currently, it is unknown whether AD-related alterations in central olfactory system neural activity, as measured by functional magnetic resonance imaging (fMRI), are detectable beyond those observed in healthy elderly. Moreover, it is not known whether such changes are correlated with indices of odor perception and dementia. To investigate these issues, 12 early stage AD patients and 13 nondemented controls underwent fMRI while being exposed to each of three concentrations of lavender oil odorant. All participants were administered the University of Pennsylvania Smell Identification Test (UPSIT), the Mini-Mental State Examination (MMSE), the Mattis Dementia Rating Scale-2 (DRS-2), and the Clinical Dementia Rating Scale (CDR). The blood oxygen level-dependent (BOLD) signal at primary olfactory cortex (POC) was weaker in AD than in HC subjects. At the lowest odorant concentration, the BOLD signals within POC, hippocampus, and insula were significantly correlated with UPSIT, MMSE, DRS-2, and CDR scores. The BOLD signal intensity and activation volume within the POC increased significantly as a function of odorant concentration in the AD group, but not in the control group. These findings demonstrate that olfactory fMRI is sensitive to the AD-related olfactory and cognitive functional decline.
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Affiliation(s)
- Jianli Wang
- Department of Radiology, The Pennsylvania State University College of Medicine, Center for NMR Research, PA, USA
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26
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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.
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Affiliation(s)
- G Demarquay
- Unité de Neurologie Fonctionnelle et d'Epileptologie, Hôpital Neurologique Pierre Wertheimer, Lyon.
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27
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Djordjevic J, Jones-Gotman M, De Sousa K, Chertkow H. Olfaction in patients with mild cognitive impairment and Alzheimer's disease. Neurobiol Aging 2007; 29:693-706. [PMID: 17207898 DOI: 10.1016/j.neurobiolaging.2006.11.014] [Citation(s) in RCA: 243] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2006] [Revised: 11/10/2006] [Accepted: 11/19/2006] [Indexed: 12/30/2022]
Abstract
Understanding of olfactory dysfunction in Alzheimer's disease (AD) remains limited. In particular, it is not known how early in the course of the disease olfactory deficits occur, and whether they are restricted to identification or involve other aspects of olfaction. We studied olfactory (odor detection thresholds, quality discrimination, and identification) and cognitive (attention, reasoning, memory, naming and fluency) functioning in patients with AD, with mild cognitive impairment (MCI), and in normal elderly control (NEC) participants. MCI patients were impaired in olfactory sensitivity and identification, while a discrimination deficit was accounted for by abnormal thresholds. AD patients were impaired in all three domains, and were worse than the MCI group. Odor discrimination (OD) and identification performance correlated more prominently than detection thresholds with performance on neuropsychological tests. We concluded that deficits in olfactory detection thresholds and identification occur early in AD, before clinical symptoms are fully developed, and decline further over the course of the disease. High detection thresholds, together with impaired identification, may be useful as an early indicator of AD.
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Affiliation(s)
- Jelena Djordjevic
- Montreal Neurological Institute, 3801 University Street, Department of Neurology and Neurosurgery, McGill University, Montreal, H3A 2B4, Québec, Canada.
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28
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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.
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Affiliation(s)
- Mark W Albers
- Department of Neurology, Columbia UniversityCollege of Physicians and Surgeons, 710 West 168th Street,New York, NY 10032, USA.
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29
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Kareken DA, Claus ED, Sabri M, Dzemidzic M, Kosobud AEK, Radnovich AJ, Hector D, Ramchandani VA, O'Connor SJ, Lowe M, Li TK. Alcohol-Related Olfactory Cues Activate the Nucleus Accumbens and Ventral Tegmental Area in High-Risk Drinkers: Preliminary Findings. Alcohol Clin Exp Res 2006; 28:550-7. [PMID: 15100605 DOI: 10.1097/01.alc.0000122764.60626.af] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The mesocorticolimbic dopamine system is implicated in motivation and reward and may be involved in the development of alcoholism. METHODS We used functional magnetic resonance imaging to study the blood oxygen level-dependent (BOLD) response to alcohol-related olfactory stimuli (AROS; odors of beer and whiskey) and non-alcohol-related olfactory stimuli (NAROS; odors of grass and leather) in 10 high-risk (HR) drinkers (average drinks per week, 19.99; SD, 6.99; all with > or = 2 first- or second-degree alcoholic relatives) and 5 low-risk (LR) social drinking controls (drinks per week, 2.82; SD, 2.87; 1 subject had 1 second-degree alcoholic relative). Data were analyzed with SPM99 and random effects analysis by using regions of interest and corrected cluster statistics (p < 0.05) to focus on the nucleus accumbens (NAc) and ventral tegmental area (VTA). RESULTS In HR subjects, there was a greater BOLD signal increase in the NAc during AROS than during clean air. BOLD signal increases during AROS were also greater in the NAc than the signal increases induced by NAROS. The AROS signal was significantly greater than the NAROS signal in a small number of voxels in the VTA. Finally, the AROS/NAROS difference signal was larger in HR drinkers in both the NAc and VTA. CONCLUSIONS Alcoholic olfactory cues may invoke the dopaminergic mesocorticolimbic system to a greater degree than nonalcoholic odors and could be effective tools in exploring the role of the dopamine system in susceptibility to alcoholism.
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Affiliation(s)
- David A Kareken
- Department of Neurology, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA.
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30
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Plailly J, Bensafi M, Pachot-Clouard M, Delon-Martin C, Kareken DA, Rouby C, Segebarth C, Royet JP. Involvement of right piriform cortex in olfactory familiarity judgments. Neuroimage 2005; 24:1032-41. [PMID: 15670680 DOI: 10.1016/j.neuroimage.2004.10.028] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2004] [Revised: 10/12/2004] [Accepted: 10/26/2004] [Indexed: 11/21/2022] Open
Abstract
Previous studies have shown activation of right orbitofrontal cortex during judgments of odor familiarity. In the present study, we sought to extend our knowledge about the neural circuits involved in such a task by exploring the involvement of the right prefrontal areas and limbic/primary olfactory structures. Fourteen right-handed male subjects were tested using fMRI with a single functional run of two olfactory conditions (odor detection and familiarity judgments). Each condition included three epochs. During the familiarity condition, subjects rated whether odors were familiar or unfamiliar. During the detection condition, participants decided if odors were present. When contrasting the familiarity with the detection conditions, activated areas were found mainly in the right piriform cortex (PC) and hippocampus, the left inferior frontal gyrus and amygdala, and bilaterally in the mid-fusiform gyrus. Further analyses demonstrated that the right PC was more strongly activated than the left PC. This result supports the notion that the right PC is preferentially involved in judgments of odor familiarity.
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Affiliation(s)
- Jane Plailly
- Neurosciences et Systèmes Sensoriels, Université Claude Bernard Lyon 1, UMR CNRS 5020, IFR 19, Institut Fédératif des Neurosciences de Lyon, 50 Avenue Tony Garnier, 69366 Lyon Cedex 07, France.
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Kareken DA, Sabri M, Radnovich AJ, Claus E, Foresman B, Hector D, Hutchins GD. Olfactory system activation from sniffing: effects in piriform and orbitofrontal cortex. Neuroimage 2004; 22:456-65. [PMID: 15110039 DOI: 10.1016/j.neuroimage.2004.01.008] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2003] [Revised: 01/07/2004] [Accepted: 01/08/2004] [Indexed: 10/26/2022] Open
Abstract
Neuroimaging studies suggest that piriform cortex is activated at least in part by sniffing. We used H(2)(15)O positron emission tomography (PET) to study 15 healthy volunteers while they participated in four conditions, two of which were sniffing odorants and odorless air. The remaining two conditions involved a constant, very low flow of either odorized or odorless air during velopharyngeal closure (VPC), a technique that prevents subject-induced airflow through the nasal passages. Contrary to expectation, sniffing under odorless conditions did not induce significant piriform and surrounding cortical (PC+) activity when compared to odorless VPC, even at a liberal statistical threshold. However, a small correlation emerged in PC+ between the difference signal of [odorless sniffing - odorless VPC] and peak rate of nasal pressure change. PC+ activity was, however, strongly evoked by odorant exposure during sniffing and VPC, with neither technique showing greater activation. Activity in orbitofrontal (olfactory association) cortex was absent during odorant stimulation (OS) with VPC, but present during odorant sniffing. Sniffing may therefore play an important role in facilitating the higher-order analysis of odors. A right orbitofrontal region was also activated with odorless sniffing, which suggests a possible orbitofrontal role in guided olfactory exploration.
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Affiliation(s)
- David A Kareken
- Department of Neurology, Neuropsychology Section (RI 1773), Indiana University School of Medicine, Indianapolis, IN 46202, USA.
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Fladby T, Bryhn G, Halvorsen O, Rosé I, Wahlund M, Wiig P, Wetterberg L. Olfactory response in the temporal cortex of the elderly measured with near-infrared spectroscopy: a preliminary feasibility study. J Cereb Blood Flow Metab 2004; 24:677-80. [PMID: 15181375 DOI: 10.1097/01.wcb.0000119966.74298.5c] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The pathway for the olfactory response may be affected at an early stage of Alzheimer's disease. Measurement of the olfactory response in the elderly is therefore of particular interest. In this feasibility study, near-infrared spectroscopy was used to measure the olfactory response in 21 patients aged 56 to 79 years. Eight subjects had no memory complaints whereas 13 had subjective memory complaints, mild cognitive impairment, or very mild Alzheimer's disease. The optodes were placed over the temporal lobe, with the emitting optode over the pole and the receiving optode over the superior gyrus. The response to vanilla (1% in sterile H2O) in a test tube held immediately beneath the nostrils was compared to the response to sterile H2O only. Four control subjects had a clearly definable response with increased oxyhemoglobin and decreased deoxyhemoglobin bilaterally. The response was measured as the sum of the deviation of oxygenated and deoxygenated hemoglobin from baseline mean. With a cut-off determined after examination of responses to vanilla and sham stimulus, group difference was significant for response to vanilla (chi2 test, P = 0.03). Response amplitudes to vanilla in the patient group were within the range of those to sham stimuli.
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Affiliation(s)
- Tormod Fladby
- University of Oslo, Departments of Neurology and Neuropsychiatry at Akershus University Hospital, Norway
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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.
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Affiliation(s)
- Alexandra Economou
- Department of Psychology, School of Philosophy, The University of Athens, Panepistimiopolis, Athens, Greece.
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Kareken DA, Mosnik DM, Doty RL, Dzemidzic M, Hutchins GD. Functional anatomy of human odor sensation, discrimination, and identification in health and aging. Neuropsychology 2003; 17:482-95. [PMID: 12959514 DOI: 10.1037/0894-4105.17.3.482] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Aging of cerebral olfactory regions was studied in 5 younger and 6 older healthy adults, matched by odor discrimination and identification scores, with positron emission tomography during odor sensory stimulation, discrimination, and identification tasks. Sensory stimulation engaged bilateral piriform and orbitofrontal regions, but neither discrimination nor identification evoked added temporal or orbital activity. Discrimination involved the hippocampus, implicating its role in serial odor comparisons (olfactory working memory). Left inferior frontal activity during identification may reflect semantic associations. Older participants deactivated the left gyrus rectus/medial orbital gyrus (GR/MOG) during sensory stimulation but activated GR/MOG during discrimination and identification. Adjusting for detection threshold eliminated GR/MOG group differences during sensory stimulation. Diminished threshold may lead to reduced engagement of olfactory association areas.
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Affiliation(s)
- David A Kareken
- Department of Neurology, Indiana University School of Medicine, Indianapolis 46202, USA.
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Abstract
The psychological basis of odor quality is poorly understood. For pragmatic reason, descriptions of odor quality generally rely on profiling odors in terms of what odorants they bring to mind. It is argued here that this reliance on profiling reflects a basic property of odor perception, namely that odor quality depends on the implicit memories that an odorant elicits. This is supported by evidence indicating that odor quality as well as one's ability to discriminate odors is affected by experience. Developmental studies and cross-cultural research also point to this conclusion. In this article, these findings are reviewed and a model that attempts to account for them is proposed. Finally, the model's consistency with both neurophysiological and neuropsychological data is examined.
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Murray LL, Dickerson S, Lichtenberger B, Cox C. Effects of toy stimulation on the cognitive, communicative, and emotional functioning of adults in the middle stages of Alzheimer's disease. JOURNAL OF COMMUNICATION DISORDERS 2003; 36:101-127. [PMID: 12609577 DOI: 10.1016/s0021-9924(03)00002-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
UNLABELLED Although several clinical reports describe the benefits of toy stimulation for dementia patients, there is little empirical support for this sensory stimulation approach. The purpose of this investigation was to examine the effects of toy stimulation on the language, cognition, and emotional state of patients in the middle stages of Alzheimer's disease (AD) during a formal testing situation. Eighteen patients completed a standardized test battery and picture description task twice, once with and once without a toy stimulus present. Three AD patients completed all tasks four times (twice with and twice without the toy) to examine performance consistency. Although some patients improved their performances in the presence of a toy, there were no significant group differences between the toy and no toy conditions for any experimental measure. Of the three patients who completed experimental tasks twice in the presence of a toy, two displayed some consistent improvements whereas the remaining patient's response pattern was variable. Caregiver feedback regarding toy stimulation was positive. Methodological limitations of the current study and suggestions for future research are discussed. LEARNING OUTCOMES As a result of reading this article, the participant will be able to: (1) summarize the previous literature regarding sensory stimulation treatment approaches for patients with Alzheimer's disease or other dementing illnesses; and (2) describe the effects of toy stimulation on the linguistic and cognitive abilities, and emotional status of patients in the middle stages of Alzheimer's disease.
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Affiliation(s)
- Laura L Murray
- Department of Speech and Hearing Sciences, Indiana University, 200 S. Jordan Avenue, Bloomington, IN 47405, USA.
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Abstract
PURPOSE OF REVIEW The diagnosis of dementia rests on an improved knowledge and a better detection of early impairments, to which functional imaging can certainly contribute. RECENT FINDINGS Progress has been observed at different levels. First, the understanding of different dementias has benefited from explorations of the neural substrate of dementia symptoms and from research into new markers. Second, diverse variables (clinical, anatomical, biochemical) have been related to impaired cerebral activity in Alzheimer's disease and other dementias, and progress in image analysis and in multimodal data acquisition has allowed a better understanding of the significance of brain activity disturbances. Third, functional imaging has been applied in well-designed clinical studies, and has provided important arguments for the diagnosis of characteristic clinical syndromes in the dementias. SUMMARY The functioning of neural networks responsible for clinical symptoms in dementia remains an important research topic for functional imaging. The development of new tracers and new techniques for image processing should also improve the usefulness of brain imaging as a diagnostic tool.
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Affiliation(s)
- Eric Salmon
- Department of Neurology and Cyclotron Research Centre, University of Liege, B30 Sart Tilman, 4000 Liege, Belgium.
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