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Delgado-Lima AH, Bouhaben J, Delgado-Losada ML. The efficacy of olfactory training in improving olfactory function: a meta-analysis. Eur Arch Otorhinolaryngol 2024:10.1007/s00405-024-08733-7. [PMID: 38802578 DOI: 10.1007/s00405-024-08733-7] [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: 01/05/2024] [Accepted: 05/12/2024] [Indexed: 05/29/2024]
Abstract
PURPOSE Study the efficacy of olfactory training in smell recovery. METHODS An extensive search was performed through different databases in order to find articles analyzing the efficacy of olfactory training as a treatment for olfactory dysfunction. Methodological quality of primary studies within the final sample was assessed following PRISMA guidelines. Standardized mean differences in pre-post olfactory training groups, and also in experimental-control and pre-follow up if possible, were computed by Hedges' g effect size statistic. Each effect size was weighted by its inverse variance. RESULTS Final sample was composed of 36 articles (45 pre-post effect sizes). Contrasts were performed separately for odor identification, odor discrimination, odor threshold and general olfactory function. Moderate to large and heterogeneous effect was obtained for olfactory function (g = 0.755, k = 45, SE = 0.093, CI 95% = [0.572, 0.937]), different moderators had a significant effects, such as, training duration, age and anosmia diagnosis. CONCLUSION Olfactory training was found to have a positive and significant effect on rehabilitating the olfactory function.
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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
| | - María Luisa Delgado-Losada
- Experimental Psychology, Cognitive Processes and Speech Therapy Department, Faculty of Psychology, Complutense University of Madrid, 28223, Pozuelo de Alarcón, Spain.
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Yu P, Chen W, Jiang L, Jia Y, Xu X, Shen W, Jin N, Du H. Olfactory dysfunction and the role of stem cells in the regeneration of olfactory neurons. Heliyon 2024; 10:e29948. [PMID: 38694081 PMCID: PMC11058886 DOI: 10.1016/j.heliyon.2024.e29948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 04/08/2024] [Accepted: 04/17/2024] [Indexed: 05/03/2024] Open
Abstract
The prevalence of COVID-19 has drawn increasing attention to olfactory dysfunction among researchers. Olfactory dysfunction manifests in various clinical types, influenced by numerous pathogenic factors. Despite this diversity, the underlying pathogenesis remains largely elusive, contributing to a lack of standardized treatment approaches. However, the potential regeneration of olfactory neurons within the nasal cavity presents a promising avenue for addressing olfactory dysfunction effectively. Our review aims to delve into the current research landscape and treatment modalities concerning olfactory dysfunction, emphasizing etiology, pathogenesis, clinical interventions, and the role of stem cells in regenerating olfactory nerves. Through this comprehensive examination, we aim to provide valuable insights into understanding the onset, progression, and treatment of olfactory dysfunction diseases.
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Affiliation(s)
- Pengju Yu
- Department of Otolaryngology, Traditional Chinese Medicine Hospital of Kunshan, Jiangsu Province, China
| | - Weiguan Chen
- Operating Room, Traditional Chinese Medicine Hospital of Kunshan, Jiangsu Province, China
| | - Ling Jiang
- Operating Room, Traditional Chinese Medicine Hospital of Kunshan, Jiangsu Province, China
| | - Yufeng Jia
- Operating Room, Traditional Chinese Medicine Hospital of Kunshan, Jiangsu Province, China
| | - Xiaoyan Xu
- Operating Room, Traditional Chinese Medicine Hospital of Kunshan, Jiangsu Province, China
| | - Weiye Shen
- Operating Room, Traditional Chinese Medicine Hospital of Kunshan, Jiangsu Province, China
| | - Ni Jin
- Operating Room, Traditional Chinese Medicine Hospital of Kunshan, Jiangsu Province, China
| | - Hongjie Du
- Department of Otolaryngology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, China
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Kumpitsch C, Fischmeister FPS, Lackner S, Holasek S, Madl T, Habisch H, Wolf A, Schöpf V, Moissl-Eichinger C. Reduced olfactory performance is associated with changed microbial diversity, oralization, and accumulation of dead biomaterial in the nasal olfactory area. Microbiol Spectr 2024; 12:e0154923. [PMID: 38193689 PMCID: PMC10846256 DOI: 10.1128/spectrum.01549-23] [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: 04/17/2023] [Accepted: 12/09/2023] [Indexed: 01/10/2024] Open
Abstract
The partial or complete loss of the sense of smell, which affects about 20% of the population, impairs the quality of life in many ways. Dysosmia and anosmia are mainly caused by aging, trauma, infections, or even neurodegenerative disease. Recently, the olfactory area-a site containing the olfactory receptor cells responsible for odor perception-was shown to harbor a complex microbiome that reflects the state of olfactory function. This initially observed correlation between microbiome composition and olfactory performance needed to be confirmed using a larger study cohort and additional analyses. A total of 120 participants (middle-aged, no neurodegenerative disease) were enrolled in the study to further analyze the microbial role in human olfactory function. Olfactory performance was assessed using the Sniffin' Stick battery, and participants were grouped accordingly (normosmia: n = 93, dysosmia: n = 27). The olfactory microbiome was analyzed by 16S rRNA gene amplicon sequencing and supplemented by metatranscriptomics in a subset (Nose 2.0). Propidium monoazide (PMA) treatment was performed to distinguish between intact and non-intact microbiome components. The gastrointestinal microbiome of these participants was also characterized by amplicon sequencing and metabolomics and then correlated with food intake. Our results confirm that normosmics and dysosmics indeed possess a distinguishable olfactory microbiome. Alpha diversity (i.e., richness) was significantly increased in dysosmics, reflected by an increase in the number of specific taxa (e.g., Rickettsia, Spiroplasma, and Brachybacterium). Lower olfactory performance was associated with microbial signatures from the oral cavity and periodontitis (Fusobacterium, Porphyromonas, and Selenomonas). However, PMA treatment revealed a higher accumulation of dead microbial material in dysosmic subjects. The gastrointestinal microbiome partially overlapped with the nasal microbiome but did not show substantial variation with respect to olfactory performance, although the diet of dysosmic individuals was shifted toward a higher meat intake. Dysosmia is associated with a higher burden of dead microbial material in the olfactory area, indicating an impaired clearance mechanism. As the microbial community of dysosmics (hyposmics and anosmics) appears to be influenced by the oral microbiome, further studies should investigate the microbial oral-nasal interplay in individuals with partial or complete olfactory loss.IMPORTANCEThe loss of the sense of smell is an incisive event that is becoming increasingly common in today's world due to infections such as COVID-19. Although this loss usually recovers a few weeks after infection, in some cases, it becomes permanent-why is yet to be answered. Since this condition often represents a psychological burden in the long term, there is a need for therapeutic approaches. However, treatment options are limited or even not existing. Understanding the role of the microbiome in the impairment of olfaction may enable the prediction of olfactory disorders and/or could serve as a possible target for therapeutic interventions.
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Affiliation(s)
- Christina Kumpitsch
- Diagnostic and Research Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Graz, Austria
| | - Florian Ph. S. Fischmeister
- Department of Psychology, University of Graz, Graz, Austria
- Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria
- BioTechMed, Graz, Austria
| | - Sonja Lackner
- Otto Loewi Research Center, Division of Immunology, Medical University of Graz, Graz, Austria
| | - Sandra Holasek
- Otto Loewi Research Center, Division of Immunology, Medical University of Graz, Graz, Austria
| | - Tobias Madl
- BioTechMed, Graz, Austria
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Ageing, Molecular Biology and Biochemistry, Research Unit Integrative Structural Biology, Medical University of Graz, Graz, Austria
| | - Hansjörg Habisch
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Ageing, Molecular Biology and Biochemistry, Research Unit Integrative Structural Biology, Medical University of Graz, Graz, Austria
| | - Axel Wolf
- Department of Otorhinolaryngology, Medical University of Graz, Graz, Austria
| | - Veronika Schöpf
- Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Christine Moissl-Eichinger
- Diagnostic and Research Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Graz, Austria
- BioTechMed, Graz, Austria
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Kobayashi M, Miwa T, Mori E, Shiga H, Tsuzuki K, Okutani F, Hayama M, Akazawa H, Nakamura Y, Suzuki M, Matsuwaki Y, Ogino E, Shikina T, Ikeda K, Hyo Y, Kashiwagi T, Kondo K, Shibata M, Ueno T. Efficacy of tokishakuyakusan and mecobalamin on post-infectious olfactory dysfunction: A prospective multicenter study. Auris Nasus Larynx 2024; 51:99-105. [PMID: 37120318 DOI: 10.1016/j.anl.2023.04.010] [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: 11/09/2022] [Revised: 04/17/2023] [Accepted: 04/19/2023] [Indexed: 05/01/2023]
Abstract
OBJECTIVE To determine if tokishakuyakusan (TSS) is effective for treating post-infectious olfactory dysfunction (PIOD) compared with vitamin B12 (mecobalamin). METHODS We conducted a randomized, nonblinded clinical trial. Patients with PIOD enrolled in 17 hospitals and clinics from 2016 to 2020 were randomly divided into two groups, and we administered TSS or mecobalamin for 24 weeks. Their olfactory function was examined using interviews and T&T olfactometry. The improvement of olfactory dysfunction was assessed following the criteria of the Japanese Rhinologic Society. RESULTS Overall, 82 patients with PIOD were enrolled in this study. In the TSS and mecobalamin groups, 39 patients completed the medication regimen. In the TSS and mecobalamin groups, olfactory dysfunction was significantly improved based on self-reports and olfactory test results. The improvement rate of olfactory dysfunction was 56% in the TSS group and 59% in the mecobalamin group. Early intervention within 3 months produced a better prognosis than the treatment initiated after 4 months. Furthermore, age and sex differences were not observed. Both medications produced no severe adverse events. CONCLUSION The present study showed that TSS and mecobalamin might be useful for treating PIOD.
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Affiliation(s)
- Masayoshi Kobayashi
- Department of Otorhinolaryngology-Head and Neck Surgery, Mie University Graduate School of Medicine, Tsu, Japan
| | - Takaki Miwa
- Department of Otorhinolaryngology, Kanazawa Medical University, Kahoku, Japan.
| | - Eri Mori
- Dpartment of Otorhinolaryngology, The Jikei University School of Medicine, Tokyo, Japan
| | - Hideaki Shiga
- Department of Otorhinolaryngology, Kanazawa Medical University, Kahoku, Japan
| | - Kenzo Tsuzuki
- Department of Otorhinolaryngology-Head and Neck Surgery, Hyogo Medical University, Nishinomiya, Japan
| | - Fumino Okutani
- Department of Occupational Health and Otolaryngology, Kochi Medical School, Nankoku, Japan
| | - Masaki Hayama
- Department of Otorhinolaryngology-Head and Neck Surgery, Osaka University Graduate School of Medicine, Suita, Japan; Department of Otorhinolaryngology, Hyogo Prefectural Nishinomiya Hospital, Nishinomiya City, Japan
| | - Hitoshi Akazawa
- Department of Otorhinolaryngology-Head and Neck Surgery, Osaka University Graduate School of Medicine, Suita, Japan
| | - Yosuke Nakamura
- Department of Otolaryngology-Head and Neck Surgery, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Motohiko Suzuki
- Department of Otolaryngology, Head and Neck Surgery, Nagoya City University, Nagoya, Japan
| | | | | | | | - Katsuhisa Ikeda
- Department of Otorhinolaryngology, Faculty of Medicine, Juntendo University, Tokyo, Japan
| | - Yukiyoshi Hyo
- Department of Otorhinolaryngology-Head and Neck Surgery, Kawasaki Medical School, Kurashiki, Japan
| | - Takashi Kashiwagi
- Department of Otorhinolaryngology-Head and Neck Surgery, Dokkyo Medical University, Shimotsuga, Japan
| | - Kenji Kondo
- Department of Otorhinolaryngology-Head and Neck Surgery, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Minori Shibata
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Takayoshi Ueno
- Department of Otolaryngology-Head and Neck Surgery, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan
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Duan HG, Ji F, Yan MX. Treatment of Postinfectious Olfactory Dysfunction Using Corticosteroids. EAR, NOSE & THROAT JOURNAL 2024; 103:NP108-NP112. [PMID: 34464164 DOI: 10.1177/01455613211040368] [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] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVE This study aimed to analyze the efficacy of different doses and forms of corticosteroids in the treatment of postinfectious olfactory dysfunction and to specify the factors related to the curative effects. METHODS The medical records of patients diagnosed with postinfectious olfactory dysfunction from January 2018 to May 2019 were reviewed. All patients received different doses of oral corticosteroids for 12 days or inhaled corticosteroids for 1 month. RESULTS A review of the records of 43 patients showed that the mean follow-up time was 6.66 months, and the overall effective rate of treatment was 48.8%. Postinfectious olfactory dysfunction exhibited distinct seasonality, with the highest incidence in March. The curative effect was significantly related to the olfactory discrimination threshold at the first consultation (P = .022), but not significantly associated with age (P = .325), sex (P = .924), duration of disease (P = .526), follow-up time (P = .489), or treatment program (P = .330). CONCLUSIONS Different doses and forms of corticosteroids showed no significant difference in the therapeutic effect on postinfectious olfactory dysfunction. The olfactory discrimination threshold at the first consultation was the most important factor influencing the prognosis.
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Affiliation(s)
- Hong-Gang Duan
- Department of Otolaryngology, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Fang Ji
- Department of Neurology, First Affiliated Hospital of College of Medicine, Zhejiang University, Hangzhou, China
| | - Mao-Xiao Yan
- Department of Otolaryngology, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
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Mahadev A, Hentati F, Miller B, Bao J, Perrin A, Kallogjeri D, Piccirillo JF. Efficacy of Gabapentin For Post-COVID-19 Olfactory Dysfunction: The GRACE Randomized Clinical Trial. JAMA Otolaryngol Head Neck Surg 2023; 149:1111-1119. [PMID: 37733356 PMCID: PMC10514889 DOI: 10.1001/jamaoto.2023.2958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 08/02/2023] [Indexed: 09/22/2023]
Abstract
Importance The COVID-19 pandemic affected millions of people and has become a dominant etiology of olfactory dysfunction (OD). No interventions with definitive clinical utility exist. Gabapentin represents a potential therapy for COVID-19-induced OD. Objective To evaluate the efficacy of oral gabapentin on olfactory function and olfaction-related quality of life in patients with COVID-19-induced OD. Design, Setting, and Participants This pilot double-blinded, placebo-controlled randomized clinical trial (RCT) was conducted at Washington University School of Medicine in St Louis from January 7, 2022, to February 3, 2023. Adults with at least 3 months of OD after COVID-19 infection were eligible for inclusion. Participants with a history of other causes of OD or contraindications to gabapentin were excluded. Intervention Patients were randomized 1:1 to oral gabapentin or placebo. All patients underwent titration to a maximum tolerable dose, which was maintained during an 8-week fixed-dose (FD) phase then tapered off. Participants were monitored for 4 weeks following cessation of study medication. Main Outcomes and Measures Outcomes were assessed following the 8-week FD phase and 4 weeks after taper completion. The primary outcome measure was the response rate determined by subjective improvement in OD on the Clinical Global Impression of Improvement (CGI-I) after the FD phase. Other subjective and objective measures of olfactory function were also assessed as secondary outcome measures. Results Sixty-eight participants were enrolled (34 randomized to each arm), a total of 44 participants completed the FD period and 20 (45.4%) reported response to treatment with at least slight improvement in olfaction from baseline. Of those randomized, 51 (75%) were women and 56 were White (82%) with a mean (SD) age of 43 (13.5) years. Baseline demographic features including age, sex, and race and ethnicity were not significantly different between the groups. Of the 18 participants in the gabapentin group, 8 (44%) were responders and of the 26 participants in the placebo group, 12 (46%) reported response to treatment (percent difference, 1.7%; 95% CI, -31.6% to 28.2%). Mixed-model analysis of all secondary outcome measures demonstrated no clinically meaningful or statistically significant difference between the gabapentin and placebo groups throughout the trial. There were no serious adverse events. Conclusions and Relevance In this randomized clinical trial, gabapentin was not associated with statistically significant or clinically meaningful benefit over placebo and likely is not an efficacious therapy for COVID-19-induced OD. Trial Registration ClinicalTrials.gov Identifier: NCT05184192.
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Affiliation(s)
- Ashna Mahadev
- Clinical Outcomes Research Office, Department of Otolaryngology–Head and Neck Surgery, Washington University School of Medicine in St Louis, St Louis, Missouri
- University of Missouri-Kansas City School of Medicine, Kansas City, Missouri
- Family Care Health Centers, St Louis, Missouri
| | - Firas Hentati
- Clinical Outcomes Research Office, Department of Otolaryngology–Head and Neck Surgery, Washington University School of Medicine in St Louis, St Louis, Missouri
- Case Western Reserve University School of Medicine, Cleveland, Ohio
- Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Brevin Miller
- Clinical Outcomes Research Office, Department of Otolaryngology–Head and Neck Surgery, Washington University School of Medicine in St Louis, St Louis, Missouri
- University of Missouri-Kansas City School of Medicine, Kansas City, Missouri
- Family Care Health Centers, St Louis, Missouri
| | - James Bao
- Clinical Outcomes Research Office, Department of Otolaryngology–Head and Neck Surgery, Washington University School of Medicine in St Louis, St Louis, Missouri
- University of Miami Miller School of Medicine, Miami, Florida
| | - Amber Perrin
- Clinical Outcomes Research Office, Department of Otolaryngology–Head and Neck Surgery, Washington University School of Medicine in St Louis, St Louis, Missouri
| | - Dorina Kallogjeri
- Clinical Outcomes Research Office, Department of Otolaryngology–Head and Neck Surgery, Washington University School of Medicine in St Louis, St Louis, Missouri
| | - Jay F. Piccirillo
- Clinical Outcomes Research Office, Department of Otolaryngology–Head and Neck Surgery, Washington University School of Medicine in St Louis, St Louis, Missouri
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7
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Coppola DM, Reisert J. The Role of the Stimulus in Olfactory Plasticity. Brain Sci 2023; 13:1553. [PMID: 38002512 PMCID: PMC10669894 DOI: 10.3390/brainsci13111553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 11/02/2023] [Accepted: 11/02/2023] [Indexed: 11/26/2023] Open
Abstract
Plasticity, the term we use to describe the ability of a nervous system to change with experience, is the evolutionary adaptation that freed animal behavior from the confines of genetic determinism. This capacity, which increases with brain complexity, is nowhere more evident than in vertebrates, especially mammals. Though the scientific study of brain plasticity dates back at least to the mid-19th century, the last several decades have seen unprecedented advances in the field afforded by new technologies. Olfaction is one system that has garnered particular attention in this realm because it is the only sensory modality with a lifelong supply of new neurons, from two niches no less! Here, we review some of the classical and contemporary literature dealing with the role of the stimulus or lack thereof in olfactory plasticity. We have restricted our comments to studies in mammals that have used dual tools of the field: stimulus deprivation and stimulus enrichment. The former manipulation has been implemented most frequently by unilateral naris occlusion and, thus, we have limited our comments to research using this technique. The work reviewed on deprivation provides substantial evidence of activity-dependent processes in both developing and adult mammals at multiple levels of the system from olfactory sensory neurons through to olfactory cortical areas. However, more recent evidence on the effects of deprivation also establishes several compensatory processes with mechanisms at every level of the system, whose function seems to be the restoration of information flow in the face of an impoverished signal. The results of sensory enrichment are more tentative, not least because of the actual manipulation: What odor or odors? At what concentrations? On what schedule? All of these have frequently not been sufficiently rationalized or characterized. Perhaps it is not surprising, then, that discrepant results are common in sensory enrichment studies. Despite this problem, evidence has accumulated that even passively encountered odors can "teach" olfactory cortical areas to better detect, discriminate, and more efficiently encode them for future encounters. We discuss these and other less-established roles for the stimulus in olfactory plasticity, culminating in our recommended "aspirations" for the field going forward.
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Affiliation(s)
- David M. Coppola
- Biology Department, Randolph-Macon College, Ashland, VA 23005, USA
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Abdelazim MH, Mandour Z, Abdelazim AH, Ismaiel WF, Gamal M, Abourehab MA, Alghamdi S, Alghamdi MA, Alrugi RR, Alharthi RR. Intra Nasal Use of Ethylene Diamine Tetra Acetic Acid for Improving Olfactory Dysfunction Post COVID-19. Am J Rhinol Allergy 2023; 37:630-637. [PMID: 37786364 PMCID: PMC10293862 DOI: 10.1177/19458924231184055] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
BACKGROUND COVID-19 has been associated with olfactory dysfunction in many infected patients. The rise of calcium levels in the nasal secretions plays an essential role in the olfaction process with a desensitization effect on the olfactory receptor neurons and a negative impact on the olfaction transmission. Ethylene diamine tetra acetic acid (EDTA) is a chelating agent that can bind free calcium in the nasal secretions, thereby reducing the adverse effects of calcium on olfactory function. OBJECTIVES The objective of this work is to demonstrate the effect of intranasal EDTA on improving olfactory dysfunction following COVID-19. METHODS Fifty patients with a history of COVID-19 and olfactory dysfunction that persisted for more than 6 months were enrolled in the current prospective randomized clinical trial. Participants were randomized into 2 equal groups. Twenty-five patients were treated with olfactory training only, while the remaining 25 patients received treatment with olfactory training and a topical nasal spray of ethylene diamine tetra acetic acid. The olfactory function was assessed before treatment and 3 months later using the Sniffin' Sticks test. Additionally, the determination of calcium level in the nasal secretions was performed using an ion-selective electrode before treatment and 3 months later. RESULTS Eighty-eight percent of the patients treated with olfactory training in addition to EDTA exhibited clinical improvement, while 60% showed improvement in patients treated with olfactory training only. Furthermore, a significant decrease in the measured calcium level in the nasal secretions was demonstrated after the use of ethylene diamine tetra compared to patients treated with olfactory training only. CONCLUSION Ethylene diamine tetra acetic acid may be associated with an improvement of the olfactory function post-COVID-19.
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Affiliation(s)
- Mohamed H. Abdelazim
- Department of Otolaryngology, Faculty of Medicine, Al-Azhar University, Damietta, Egypt
| | - Zeyad Mandour
- Department of Otolaryngology, Alexandria University, Alexandria, Egypt
| | - Ahmed H. Abdelazim
- Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Al-Azhar University, Cairo, Egypt
| | - Wael F. Ismaiel
- Department of Otolaryngology, Faculty of Medicine, Al-Azhar University, Damietta, Egypt
| | - Mohammed Gamal
- Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Beni-Suef University, Beni-Suef, Egypt
| | - Mohammed A.S. Abourehab
- Department of Pharmaceutics, College of Pharmacy, Umm Al-Qura University, Makkah, Saudi Arabia
- Department of Pharmaceutics and Industrial Pharmacy, College of Pharmacy, Minia University, Minia, Egypt
| | - Saleh Alghamdi
- Department of Clinical Pharmacy, Faculty of Clinical Pharmacy, Al Baha University, Al Baha, Saudi Arabia
| | - Mohamed A. Alghamdi
- Department of Surgery, Division of Otolaryngology, Faculty of Medicine, Al Baha University, Al Baha City, Saudi Arabia
| | - Rehab R. Alrugi
- Pharm D student, College of Pharmacy, Shaqra University, Shaqra, Saudi Arabia
| | - Rawan R. Alharthi
- Department of Pharmacy, Dawadmi General Hospital, Dawadmi, Saudi Arabia
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9
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Rass V, Tymoszuk P, Sahanic S, Heim B, Ausserhofer D, Lindner A, Kofler M, Mahlknecht P, Boehm A, Hüfner K, Pizzini A, Sonnweber T, Kurz K, Pfeifer B, Kiechl S, Peball M, Kindl P, Putnina L, Fava E, Djamshidian A, Huber A, Wiedermann CJ, Sperner-Unterweger B, Wöll E, Beer R, Schiefecker AJ, Bellmann-Weiler R, Bachler H, Tancevski I, Pfausler B, Piccoliori G, Seppi K, Weiss G, Löffler-Ragg J, Helbok R. Distinct smell and taste disorder phenotype of post-acute COVID-19 sequelae. Eur Arch Otorhinolaryngol 2023; 280:5115-5128. [PMID: 37670171 PMCID: PMC10562286 DOI: 10.1007/s00405-023-08163-x] [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: 04/27/2023] [Accepted: 07/26/2023] [Indexed: 09/07/2023]
Abstract
PURPOSE Olfactory dysfunction (OD) commonly accompanies coronavirus disease 2019 (COVID-19). We investigated the kinetics of OD resolution following SARS-CoV-2 infection (wild-type and alpha variant) and its impact on quality of life, physical and mental health. METHODS OD prevalence was assessed in an ambulatory COVID-19 survey (n = 906, ≥ 90 days follow-up) and an observational cohort of ambulatory and hospitalized individuals (n = 108, 360 days follow-up). Co-occurrence of OD with other symptoms and effects on quality of life, physical and mental health were analyzed by multi-dimensional scaling, association rule mining and semi-supervised clustering. RESULTS Both in the ambulatory COVID-19 survey study (72%) and the observational ambulatory and hospitalized cohort (41%) self-reported OD was frequent during acute COVID-19. Recovery from self-reported OD was slow (survey: median 28 days, observational cohort: 90 days). By clustering of the survey data, we identified a predominantly young, female, comorbidity-free group of convalescents with persistent OD and taste disorders (median recovery: 90 days) but low frequency of post-acute fatigue, respiratory or neurocognitive symptoms. This smell and taste disorder cluster was characterized by a high rating of physical performance, mental health, and quality of life as compared with convalescents affected by prolonged fatigue or neurocognitive complaints. CONCLUSION Our results underline the heterogeneity of post-acute COVID-19 sequelae calling for tailored management strategies. The persistent smell and taste disorder phenotype is characterized by good clinical, physical, and mental recovery and may pose a minor challenge for public health. STUDY REGISTRATION ClinicalTrials.gov: NCT04661462 (survey study), NCT04416100 (observational cohort).
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Affiliation(s)
- Verena Rass
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | | | - Sabina Sahanic
- Department of Internal Medicine II, Medical University of Innsbruck, Innsbruck, Austria
| | - Beatrice Heim
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Dietmar Ausserhofer
- Institute of General Practice and Public Health, Claudiana College of Health Professions, Bolzano, Italy
| | - Anna Lindner
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Mario Kofler
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Philipp Mahlknecht
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Anna Boehm
- Department of Internal Medicine II, Medical University of Innsbruck, Innsbruck, Austria
| | - Katharina Hüfner
- Department of Psychiatry, Psychotherapy, Psychosomatics and Medical Psychology, University Hospital for Psychiatry II, Medical University of Innsbruck, Innsbruck, Austria
| | - Alex Pizzini
- Department of Internal Medicine II, Medical University of Innsbruck, Innsbruck, Austria
| | - Thomas Sonnweber
- Department of Internal Medicine II, Medical University of Innsbruck, Innsbruck, Austria
| | - Katharina Kurz
- Department of Internal Medicine II, Medical University of Innsbruck, Innsbruck, Austria
| | - Bernhard Pfeifer
- Tyrolean Federal Institute for Integrated Care, Innsbruck, Austria
- Division for Health Networking and Telehealth, Biomedical Informatics and Mechatronics, UMIT, Hall in Tyrol, Austria
| | - Stefan Kiechl
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Marina Peball
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Philipp Kindl
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Lauma Putnina
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Elena Fava
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Atbin Djamshidian
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Andreas Huber
- Tyrolean Federal Institute for Integrated Care, Innsbruck, Austria
| | - Christian J Wiedermann
- Institute of General Practice and Public Health, Claudiana College of Health Professions, Bolzano, Italy
| | - Barbara Sperner-Unterweger
- Department of Psychiatry, Psychotherapy, Psychosomatics and Medical Psychology, University Hospital for Psychiatry II, Medical University of Innsbruck, Innsbruck, Austria
| | - Ewald Wöll
- Department of Internal Medicine, St. Vinzenz Hospital, Zams, Austria
| | - Ronny Beer
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | | | - Rosa Bellmann-Weiler
- Department of Internal Medicine II, Medical University of Innsbruck, Innsbruck, Austria
| | - Herbert Bachler
- Institute of General Medicine, Medical University of Innsbruck, Innsbruck, Austria
| | - Ivan Tancevski
- Department of Internal Medicine II, Medical University of Innsbruck, Innsbruck, Austria
| | - Bettina Pfausler
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Giuliano Piccoliori
- Institute of General Practice and Public Health, Claudiana College of Health Professions, Bolzano, Italy
| | - Klaus Seppi
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Günter Weiss
- Department of Internal Medicine II, Medical University of Innsbruck, Innsbruck, Austria
| | - Judith Löffler-Ragg
- Department of Internal Medicine II, Medical University of Innsbruck, Innsbruck, Austria.
| | - Raimund Helbok
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria.
- Department of Neurology, Johannes Kepler University, Linz, Austria.
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10
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Han SA, Kim JK, Cho DY, Patel ZM, Rhee CS. The Olfactory System: Basic Anatomy and Physiology for General Otorhinolaryngologists. Clin Exp Otorhinolaryngol 2023; 16:308-316. [PMID: 37669740 PMCID: PMC10710919 DOI: 10.21053/ceo.2023.00185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 08/16/2023] [Accepted: 09/04/2023] [Indexed: 09/07/2023] Open
Abstract
Olfaction is one of the five basic human senses, and it is known to be one of the most primitive senses. The sense of olfaction may have been critical for human survival in prehistoric society, and although many believe its importance has diminished over time, it continues to have an impact on human interaction, bonding, and propagation of the species. Even if we are unaware of it, the sense of smell greatly affects our lives and is closely related to overall quality of life and health. Nonetheless, olfaction has been neglected from a scientific perspective compared to other senses. However, olfaction has recently received substantial attention since the loss of smell and taste has been noted as a key symptom of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Studies investigating olfaction loss in association with coronavirus disease 2019 (COVID-19) have revealed that olfactory dysfunction can be both conductive and sensorineural, possibly causing structural changes in the brain. Olfactory training is an effective treatment for olfactory dysfunction, suggesting the reorganization of neural associations. A reduced ability to smell may also alert suspicion for neurodegenerative or psychiatric disorders. Here, we summarize the basic knowledge that we, as otorhinolaryngologists, should have about the sense of smell and the peripheral and central olfactory pathways for managing and helping patients with olfactory dysfunction.
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Affiliation(s)
- Sun A Han
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Jin Kook Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, Konkuk University School of Medicine, Seoul, Korea
| | - Do-Yeon Cho
- Department of Otolaryngology-Head and Neck Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
- Division of Otolaryngology, Department of Surgery, Veterans Affairs, Birmingham, AL, USA
| | - Zara M. Patel
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Chae-Seo Rhee
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
- Sensory Organ Research Institute and Institute of Allergy and Clinical Immunology, Seoul National University Medical Research Center, Seoul, Korea
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11
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Kovacevich A, Weleff J, Claytor B, Barnett BS. Three Cases of Reported Improvement in Microsmia and Anosmia Following Naturalistic Use of Psilocybin and LSD. J Psychoactive Drugs 2023; 55:672-679. [PMID: 37650700 DOI: 10.1080/02791072.2023.2253538] [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: 04/17/2023] [Revised: 08/01/2023] [Accepted: 08/03/2023] [Indexed: 09/01/2023]
Abstract
Cultural awareness of anosmia and microsmia has recently increased due to their association with COVID-19, though treatment for these conditions is limited. A growing body of online media claims that individuals have noticed improvement in anosmia and microsmia following classic psychedelic use. We report what we believe to be the first three cases recorded in the academic literature of improvement in olfactory impairment after psychedelic use. In the first case, a man who developed microsmia after a respiratory infection experienced improvement in smell after the use of 6 g of psilocybin containing mushrooms. In the second case, a woman with anosmia since childhood reported olfactory improvement after ingestion of 100 µg of lysergic acid diethylamide (LSD). In the third case, a woman with COVID-19-related anosmia reported olfactory improvement after microdosing 0.1 g of psilocybin mushrooms three times. Following a discussion of these cases, we explore potential mechanisms for psychedelic-facilitated improvement in olfactory impairment, including serotonergic effects, increased neuroplasticity, and anti-inflammatory effects. Given the need for novel treatments for olfactory dysfunction, increasing reports describing improvement in these conditions following psychedelic use and potential biological plausibility, we believe that the possible therapeutic benefits of psychedelics for these conditions deserve further investigation.
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Affiliation(s)
| | - Jeremy Weleff
- Department of Psychiatry and Psychology, Cleveland Clinic, Cleveland, USA
- Department of Psychiatry, Yale University School of Medicine, Cleveland, USA
| | | | - Brian S Barnett
- Department of Psychiatry and Psychology, Cleveland Clinic, Cleveland, USA
- Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, USA
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12
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Pieniak M, Seidel K, Oleszkiewicz A, Gellrich J, Karpinski C, Fitze G, Schriever VA. Olfactory training effects in children after mild traumatic brain injury. Brain Inj 2023; 37:1272-1284. [PMID: 37486172 DOI: 10.1080/02699052.2023.2237889] [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: 11/09/2022] [Revised: 05/29/2023] [Accepted: 06/12/2023] [Indexed: 07/25/2023]
Abstract
OBJECTIVE Mild traumatic brain injury (mTBI) might impair the sense of smell and cognitive functioning. Repeated, systematic exposure to odors, i.e., olfactory training (OT) has been proposed for treatment of olfactory dysfunctions, including post-traumatic smell loss. Additionally, OT has been shown to mitigate cognitive deterioration in older population and enhance selected cognitive functions in adults. We aimed to investigate olfactory and cognitive effects of OT in the pediatric population after mTBI, likely to exhibit cognitive and olfactory deficits. METHODS Our study comprised 159 children after mTBI and healthy controls aged 6-16 years (M = 9.68 ± 2.78 years, 107 males), who performed 6-months-long OT with a set of 4 either high- or low-concentrated odors. Before and after OT we assessed olfactory functions, fluid intelligence, and executive functions. RESULTS OT with low-concentrated odors increased olfactory sensitivity in children after mTBI. Regardless of health status, children who underwent OT with low-concentrated odors had higher fluid intelligence scores at post-training measurement, whereas scores of children performing OT with high-concentrated odors did not change. CONCLUSION Our study suggests that OT with low-concentrated odors might accelerate rehabilitation of olfactory sensitivity in children after mTBI and support cognitive functions in the area of fluid intelligence regardless of head trauma.
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Affiliation(s)
- Michal Pieniak
- Smell & Taste Clinic, Department of Otorhinolaryngology, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
- Faculty of Historical and Pedagogical Sciences, Institute of Psychology, University of Wrocław, Wroclaw, Poland
| | - Katharina Seidel
- Abteilung Neuropädiatrie, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Anna Oleszkiewicz
- Smell & Taste Clinic, Department of Otorhinolaryngology, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
- Faculty of Historical and Pedagogical Sciences, Institute of Psychology, University of Wrocław, Wroclaw, Poland
| | - Janine Gellrich
- Abteilung Neuropädiatrie, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Christian Karpinski
- Klinik Und Poliklinik Für Kinderchirurgie, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Guido Fitze
- Klinik Und Poliklinik Für Kinderchirurgie, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Valentin A Schriever
- Abteilung Neuropädiatrie, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
- Center for Chronically Sick Children (Sozialpädiatrisches Zentrum, SPZ), Charité - Universitätsmedizin Berlin, Berlin, Germany
- Department of Pediatric Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany
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13
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Gunder N, Dörig P, Witt M, Welge-Lüssen A, Menzel S, Hummel T. Future therapeutic strategies for olfactory disorders: electrical stimulation, stem cell therapy, and transplantation of olfactory epithelium-an overview. HNO 2023; 71:35-43. [PMID: 36734997 PMCID: PMC9897160 DOI: 10.1007/s00106-022-01249-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/19/2022] [Indexed: 02/04/2023]
Abstract
Olfactory disorders may be temporary or permanent and can have various causes. Currently, many COVID-19 patients report a reduced or complete loss of olfactory function. A wide range of treatment options have been investigated in the past, such as olfactory training, acupuncture, medical therapy, transcranial magnetic stimulation, or surgical excision of olfactory epithelium, e.g., in severe qualitative smell disorders. The development of a bioelectric nose, e.g., in connection with direct electrical stimulation or transplantation of olfactory epithelium or stem cells, represent treatment options of the future. The basis of these developments and the state of knowledge is discussed in the following work.
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Affiliation(s)
- N Gunder
- Klinik und Poliklinik für Hals-, Nasen- und Ohrenheilkunde, Universitätsklinikum Carl Gustav Carus an der Technischen Universität Dresden, Fetscherstr. 74, 01307, Dresden, Germany.
| | - P Dörig
- Universitäts-HNO Klinik Basel, Basel, Switzerland
| | - M Witt
- Institut für Anatomie, Universitätsmedizin Rostock, Rostock, Germany
| | | | - S Menzel
- Klinik und Poliklinik für Hals-, Nasen- und Ohrenheilkunde, Universitätsklinikum Carl Gustav Carus an der Technischen Universität Dresden, Fetscherstr. 74, 01307, Dresden, Germany
| | - T Hummel
- Klinik und Poliklinik für Hals-, Nasen- und Ohrenheilkunde, Universitätsklinikum Carl Gustav Carus an der Technischen Universität Dresden, Fetscherstr. 74, 01307, Dresden, Germany
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14
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Kikuta S, Han B, Yamasoba T. Heterogeneous Damage to the Olfactory Epithelium in Patients with Post-Viral Olfactory Dysfunction. J Clin Med 2023; 12:5007. [PMID: 37568409 PMCID: PMC10419384 DOI: 10.3390/jcm12155007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 07/27/2023] [Accepted: 07/29/2023] [Indexed: 08/13/2023] Open
Abstract
OBJECTIVES Post-viral olfactory dysfunction (PVOD) is a neurogenic disorder caused by a common cold virus. Based on the homology of deduced amino acid sequences, olfactory sensory neurons (OSNs) in both mice and humans express either class I or class II odorant receptor genes encoding class I and class II OSNs. The purpose of this study was to determine whether OSN damage in PVOD occurs uniformly in both neuron types. MATERIALS AND METHODS The characteristics of PVOD patients were compared with those of patients with chronic rhinosinusitis (CRS) or post-traumatic olfactory dysfunction (PTOD). Briefly, subjects underwent orthonasal olfaction tests using five different odors (T&T odors) and a retronasal olfaction test using a single odor (IVO odor). The regions in the mouse olfactory bulb (OB) activated by the T&T and the IVO odors were also examined. RESULTS Multivariate analysis of 307 cases of olfactory dysfunction (PVOD, 118 cases; CRS, 161 cases; and PTOD, 28 cases) revealed that a combination of responses to the IVO odor, but not to the T&T odors, is characteristic of PVOD, with high specificity (p < 0.001). Imaging analysis of GCaMP3 mice showed that the IVO odor selectively activated the OB region in which the axons of class I OSNs converged, whereas the T&T odors broadly activated the OB region in which axons of class I and class II OSNs converged. CONCLUSIONS A response to T&T odors, but not IVO odor, in PVOD suggests that class I OSNs are injured preferentially, and that OSN damage in PVOD may occur heterogeneously in a neuron-type-dependent manner.
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Affiliation(s)
- Shu Kikuta
- Department of Otolaryngology-Head and Neck Surgery, Faculty of Medicine, Nihon University, 30-1, Oyaguchi Kami-cho, Itabashi-ku, Tokyo 173-8610, Japan
- Department of Otolaryngology-Head and Neck Surgery, Faculty of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan; (B.H.); (T.Y.)
| | - Bing Han
- Department of Otolaryngology-Head and Neck Surgery, Faculty of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan; (B.H.); (T.Y.)
| | - Tatsuya Yamasoba
- Department of Otolaryngology-Head and Neck Surgery, Faculty of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan; (B.H.); (T.Y.)
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15
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Woo CC, Miranda B, Sathishkumar M, Dehkordi-Vakil F, Yassa MA, Leon M. Overnight olfactory enrichment using an odorant diffuser improves memory and modifies the uncinate fasciculus in older adults. Front Neurosci 2023; 17:1200448. [PMID: 37554295 PMCID: PMC10405466 DOI: 10.3389/fnins.2023.1200448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 07/07/2023] [Indexed: 08/10/2023] Open
Abstract
OBJECTIVE Cognitive loss in older adults is a growing issue in our society, and there is a need to develop inexpensive, simple, effective in-home treatments. This study was conducted to explore the use of olfactory enrichment at night to improve cognitive ability in healthy older adults. METHODS Male and female older adults (N = 43), age 60-85, were enrolled in the study and randomly assigned to an Olfactory Enriched or Control group. Individuals in the enriched group were exposed to 7 different odorants a week, one per night, for 2 h, using an odorant diffuser. Individuals in the control group had the same experience with de minimis amounts of odorant. Neuropsychological assessments and fMRI scans were administered at the beginning of the study and after 6 months. RESULTS A statistically significant 226% improvement was observed in the enriched group compared to the control group on the Rey Auditory Verbal Learning Test and improved functioning was observed in the left uncinate fasciculus, as assessed by mean diffusivity. CONCLUSION Minimal olfactory enrichment administered at night produces improvements in both cognitive and neural functioning. Thus, olfactory enrichment may provide an effective and low-effort pathway to improved brain health.
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Affiliation(s)
- Cynthia C. Woo
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
| | - Blake Miranda
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA, United States
| | - Mithra Sathishkumar
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA, United States
| | | | - Michael A. Yassa
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA, United States
| | - Michael Leon
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA, United States
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA, United States
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16
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Liu ZY, Vaira LA, Boscolo-Rizzo P, Walker A, Hopkins C. Post-viral olfactory loss and parosmia. BMJ MEDICINE 2023; 2:e000382. [PMID: 37841969 PMCID: PMC10568123 DOI: 10.1136/bmjmed-2022-000382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 05/26/2023] [Indexed: 10/17/2023]
Abstract
The emergence of SARS-CoV-2 has brought olfactory dysfunction to the forefront of public awareness, because up to half of infected individuals could develop olfactory dysfunction. Loss of smell-which can be partial or total-in itself is debilitating, but the distortion of sense of smell (parosmia) that can occur as a consequence of a viral upper respiratory tract infection (either alongside a reduction in sense of smell or as a solo symptom) can be very distressing for patients. Incidence of olfactory loss after SARS-CoV-2 infection has been estimated by meta-analysis to be around 50%, with more than one in three who will subsequently report parosmia. While early loss of sense of smell is thought to be due to infection of the supporting cells of the olfactory epithelium, the underlying mechanisms of persistant loss and parosmia remain less clear. Depletion of olfactory sensory neurones, chronic inflammatory infiltrates, and downregulation of receptor expression are thought to contribute. There are few effective therapeutic options, so support and olfactory training are essential. Further research is required before strong recommendations can be made to support treatment with steroids, supplements, or interventions applied topically or injected into the olfactory epithelium in terms of improving recovery of quantitative olfactory function. It is not yet known whether these treatments will also achieve comparable improvements in parosmia. This article aims to contextualise parosmia in the setting of post-viral olfactory dysfunction, explore some of the putative molecular mechanisms, and review some of the treatment options available.
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Affiliation(s)
- Zhen Yu Liu
- Department of ENT Surgery, Royal Brisbane and Women's Hospital, Herston, QLD, Australia
| | - Luigi Angelo Vaira
- Department of Medicine, Surgery and Pharmacy, University of Sassari, Sassari, Sardegna, Italy
| | - Paolo Boscolo-Rizzo
- Department of Medical, Surgical, and Health Sciences, Section of Otolaryngology, University of Trieste, Trieste, Italy
| | - Abigail Walker
- Department of ENT, Royal Brisbane and Women's Hospital, Herston, QLD, Australia
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17
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Alarfaj AA, Aldrweesh AK, Aldoughan AF, Alarfaj SM, Alabdulqader FK, Alyahya KA. Olfactory Dysfunction following COVID-19 and the Potential Benefits of Olfactory Training. J Clin Med 2023; 12:4761. [PMID: 37510876 PMCID: PMC10381506 DOI: 10.3390/jcm12144761] [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: 04/22/2023] [Revised: 06/26/2023] [Accepted: 07/13/2023] [Indexed: 07/30/2023] Open
Abstract
COVID-19 is associated with a common symptom of olfactory dysfunction, which may persist even after the infection is resolved. Olfactory training (OT) has emerged as the most effective intervention for post-viral olfactory dysfunction. OT involves daily exposure of the olfactory system to various odors. The current study aims to explore olfactory dysfunction following COVID-19 and the potential benefits of olfactory training. METHODS This is a cross-sectional study conducted among adults aged 18-60 living in Alahssa, Saudi Arabia. An online questionnaire containing an informed consent form and a survey to collect demographic data, vaccination status, level of loss of smell and taste, and the level of awareness about olfactory training (OT) was distributed among all participants who agreed to participate in this study. RESULTS The study included 524 participants and presented their baseline characteristics, including age, gender, COVID-19 infection status, and complaints. Most patients were female (66.0%), and 46.2% had previously been infected with COVID-19. About 54.8% of participants reported chemosensory dysfunction, while 286 had olfactory dysfunction. Of those, 29.8% had anosmia, 16.8% had hyposmia, and 8.0% had parosmia. Results suggest that being fully or partially vaccinated may offer some protection against olfactory dysfunction compared to being unvaccinated. Adherence to olfactory training was associated with improvement in the sense of smell. CONCLUSIONS The study highlights the importance of awareness and adherence to olfactory training, which may improve the sense of smell in individuals with chemosensory dysfunction. The findings of this study can inform public health policies and interventions aimed at reducing the burden of olfactory dysfunction associated with COVID-19 vaccination.
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Affiliation(s)
- Abdullah A Alarfaj
- Otolaryngology Unit, Department of Surgery, King Faisal University, Al-Ahsa 31982, Saudi Arabia
| | | | | | | | | | - Khalid A Alyahya
- Otolaryngology Unit, Department of Surgery, King Faisal University, Al-Ahsa 31982, Saudi Arabia
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18
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Rabady S, Hoffmann K, Aigner M, Altenberger J, Brose M, Costa U, Denk-Linnert DM, Gruber S, Götzinger F, Helbok R, Hüfner K, Koczulla R, Kurz K, Lamprecht B, Leis S, Löffler J, Müller CA, Rittmannsberger H, Rommer PS, Sator P, Strenger V, Struhal W, Untersmayr E, Vonbank K, Wancata J, Weber T, Wendler M, Zwick RH. [S1 guidelines for the management of postviral conditions using the example of post-COVID-19]. Wien Klin Wochenschr 2023; 135:525-598. [PMID: 37555900 PMCID: PMC10504206 DOI: 10.1007/s00508-023-02242-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/14/2023] [Indexed: 08/10/2023]
Abstract
These S1 guidelines are an updated and expanded version of the S1 guidelines on long COVID differential diagnostic and management strategies. They summarize the state of knowledge on postviral conditions like long/post COVID at the time of writing. Due to the dynamic nature of knowledge development, they are intended to be "living guidelines". The focus is on practical applicability at the level of primary care, which is understood to be the appropriate place for initial access and for primary care and treatment. The guidelines provide recommendations on the course of treatment, differential diagnostics of the most common symptoms that can result from infections like with SARS-CoV-2, treatment options, patient management and care, reintegration and rehabilitation. The guidelines have been developed through an interdisciplinary and interprofessional process and provide recommendations on interfaces and possibilities for collaboration.
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Affiliation(s)
- Susanne Rabady
- Department Allgemeine Gesundheitsstudien, Kompetenzzentrum für Allgemein- und Familienmedizin, Karl Landsteiner Privatuniversität für Gesundheitswissenschaften, Dr. Karl-Dorrek-Str. 30, 3500, Krems, Österreich.
| | - Kathryn Hoffmann
- Leiterin der Abteilung Primary Care Medicine, Medizinische Universität Wien, Währinger Gürtel 18-20, 1090, Wien, Österreich
| | - Martin Aigner
- Abteilung für Psychiatrie und psychotherapeutische Medizin, Karl Landsteiner Privatuniversität für Gesundheitswissenschaften, Dr. Karl-Dorrek-Str. 30, 3500, Krems, Österreich
| | - Johann Altenberger
- Pensionsversicherungsanstalt, Rehabilitationszentrum Großgmain, Salzburger Str. 520, 5084, Großgmain, Österreich
| | - Markus Brose
- Department Allgemeine Gesundheitsstudien, Kompetenzzentrum für Allgemein- und Familienmedizin, Karl Landsteiner Privatuniversität für Gesundheitswissenschaften, Dr. Karl-Dorrek-Str. 30, 3500, Krems, Österreich
| | - Ursula Costa
- Ergotherapie und Handlungswissenschaft, fhg - Zentrum für Gesundheitsberufe Tirol GmbH/fh, Innrain 98, 6020, Innsbruck, Österreich
| | - Doris-Maria Denk-Linnert
- Klinische Abteilung für Allgemeine Hals‑, Nasen- und Ohrenkrankheiten, Klin. Abteilung Phoniatrie-Logopädie, Medizinische Universität Wien, Währinger Gürtel 18-20, 1090, Wien, Österreich
| | - Samuel Gruber
- Department Allgemeine Gesundheitsstudien, Kompetenzzentrum für Allgemein- und Familienmedizin, Karl Landsteiner Privatuniversität für Gesundheitswissenschaften, Dr. Karl-Dorrek-Str. 30, 3500, Krems, Österreich
| | - Florian Götzinger
- Abteilung für Kinderheilkunde, Klinik Ottakring, Montleartstr. 37, 1160, Wien, Österreich
| | - Raimund Helbok
- Universitätsklinik für Neurologie, Johannes Kepler Universität Linz, Standort Neuromed Campus & Med Campus Kepler Universitätsklinikum GmbH, 4020, Linz, Österreich
| | - Katharina Hüfner
- Dep. für Psychiatrie, Psychotherapie, Psychosomatik und Medizinische Psychologie, Universitätsklinik für Psychiatrie II, Medizinische Universität Innsbruck, Anichstr. 35, 6020, Innsbruck, Österreich
| | - Rembert Koczulla
- Fachbereich Medizin, Klinik für Pneumologie Marburg, Baldingerstr., 35035, Marburg, Deutschland
| | - Katharina Kurz
- Innere Medizin II, Medizinische Universität Innsbruck, Anichstr. 35, 6020, Innsbruck, Österreich
| | - Bernd Lamprecht
- Universitätsklinik für Innere Medizin mit Schwerpunkt Pneumologie, Kepler Universitätsklinikum, 4020, Linz, Österreich
| | - Stefan Leis
- Universitätsklinik für Neurologie der PMU, MME Universitätsklinikum Salzburg Christian-Doppler-Klinik, Ignaz-Harrer-Str. 79, 5020, Salzburg, Österreich
| | - Judith Löffler
- Innere Medizin II, Medizinische Universität Innsbruck, Anichstr. 35, 6020, Innsbruck, Österreich
| | - Christian A Müller
- Klinische Abteilung für Allgemeine Hals‑, Nasen- und Ohrenkrankheiten, Klin. Abteilung für Allgemeine HNO, Medizinische Universität Wien, Währinger Gürtel 18-20, 1090, Wien, Österreich
| | | | - Paulus S Rommer
- Universitätsklinik für Neurologie, Medizinische Universität Wien, Währinger Gürtel 18-20, 1090, Wien, Österreich
| | - Paul Sator
- Dermatologische Abteilung, Klinik Hietzing, Wolkersbergenstr. 1, 1130, Wien, Österreich
| | - Volker Strenger
- Klinische Abteilung für Allgemeinpädiatrie, Universitätsklinik für Kinder- und Jugendheilkunde, Medizinische Universität Graz, 8036, Graz, Österreich
| | - Walter Struhal
- Klinische Abteilung für Neurologie, Universitätsklinikum Tulln, Karl Landsteiner Privatuniversität für Gesundheitswissenschaften, Alter Ziegelweg 10, 3430, Tulln an der Donau, Österreich
| | - Eva Untersmayr
- Institut für Pathophysiologie und Allergieforschung Zentrum für Pathophysiologie, Infektiologie und Immunologie, Medizinische Universität Wien, Währinger Gürtel 18-20, 1090, Wien, Österreich
| | - Karin Vonbank
- Klinische Abteilung für Pulmologie, Medizinische Universität Wien, Währinger Gürtel 18-20, 1090, Wien, Österreich
| | - Johannes Wancata
- Klinische Abteilung für Sozialpsychiatrie, Medizinische Universität Wien, Währinger Gürtel 18-20, 1090, Wien, Österreich
| | - Thomas Weber
- Kardiologische Abteilung Klinikum Wels-Grieskirchen, Grieskirchnerstr. 42, 4600, Wels, Österreich
| | | | - Ralf-Harun Zwick
- Ludwig Boltzmann Institute for Rehabilitation Research, Kurbadstr. 14, 1100, Wien, Österreich
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Chung TWH, Zhang H, Wong FKC, Sridhar S, Lee TMC, Leung GKK, Chan KH, Lau KK, Tam AR, Ho DTY, Cheng VCC, Yuen KY, Hung IFN, Mak HKF. A Pilot Study of Short-Course Oral Vitamin A and Aerosolised Diffuser Olfactory Training for the Treatment of Smell Loss in Long COVID. Brain Sci 2023; 13:1014. [PMID: 37508945 PMCID: PMC10377650 DOI: 10.3390/brainsci13071014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 06/20/2023] [Accepted: 06/27/2023] [Indexed: 07/30/2023] Open
Abstract
Background: Olfactory dysfunction (OD) is a common neurosensory manifestation in long COVID. An effective and safe treatment against COVID-19-related OD is needed. Methods: This pilot trial recruited long COVID patients with persistent OD. Participants were randomly assigned to receive short-course (14 days) oral vitamin A (VitA; 25,000 IU per day) and aerosolised diffuser olfactory training (OT) thrice daily (combination), OT alone (standard care), or observation (control) for 4 weeks. The primary outcome was differences in olfactory function by butanol threshold tests (BTT) between baseline and end-of-treatment. Secondary outcomes included smell identification tests (SIT), structural MRI brain, and serial seed-based functional connectivity (FC) analyses in the olfactory cortical network by resting-state functional MRI (rs-fMRI). Results: A total of 24 participants were randomly assigned to receive either combination treatment (n = 10), standard care (n = 9), or control (n = 5). Median OD duration was 157 days (IQR 127-175). Mean baseline BTT score was 2.3 (SD 1.1). At end-of-treatment, mean BTT scores were significantly higher for the combination group than control (p < 0.001, MD = 4.4, 95% CI 1.7 to 7.2) and standard care (p = 0.009) groups. Interval SIT scores increased significantly (p = 0.009) in the combination group. rs-fMRI showed significantly higher FC in the combination group when compared to other groups. At end-of-treatment, positive correlations were found in the increased FC at left inferior frontal gyrus and clinically significant improvements in measured BTT (r = 0.858, p < 0.001) and SIT (r = 0.548, p = 0.042) scores for the combination group. Conclusions: Short-course oral VitA and aerosolised diffuser OT was effective as a combination treatment for persistent OD in long COVID.
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Affiliation(s)
- Tom Wai-Hin Chung
- Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Hui Zhang
- Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong, China
- Research Institute for Intelligent Wearable Systems, The Hong Kong Polytechnic University, Hong Kong, China
| | - Fergus Kai-Chuen Wong
- Department of Ear, Nose and Throat, Pamela Youde Nethersole Eastern Hospital, Hong Kong, China
| | - Siddharth Sridhar
- Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China
- Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China
| | - Tatia Mei-Chun Lee
- Department of Psychology, The University of Hong Kong, Hong Kong, China
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China
| | - Gilberto Ka-Kit Leung
- Department of Surgery, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Koon-Ho Chan
- Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Kui-Kai Lau
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China
- Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Anthony Raymond Tam
- Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Deborah Tip-Yin Ho
- Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Vincent Chi-Chung Cheng
- Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Kwok-Yung Yuen
- Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China
- Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China
- The Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The University of Hong Kong, Hong Kong, China
| | - Ivan Fan-Ngai Hung
- Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China
- Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
- The Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The University of Hong Kong, Hong Kong, China
| | - Henry Ka-Fung Mak
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China
- Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
- Alzheimer's Disease Research Network, The University of Hong Kong, Hong Kong, China
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20
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Donelli D, Antonelli M, Valussi M. Olfactory training with essential oils for patients with post-COVID-19 smell dysfunction: A case series. Eur J Integr Med 2023; 60:102253. [PMID: 37163157 PMCID: PMC10102705 DOI: 10.1016/j.eujim.2023.102253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 04/11/2023] [Accepted: 04/13/2023] [Indexed: 05/11/2023]
Abstract
Introduction It is estimated that up to one third of COVID-19 patients can develop long-lasting smell dysfunction. Viral infections, especially COVID-19, can cause anosmia through different pathomechanisms, and different strategies have been proposed for effectively managing post-COVID-19 olfactory dysfunction in clinical practice, with olfactory training being recommended as a first-line treatment option. Methods This report describes a non-consecutive series of clinical cases. After COVID-19, eight cases (5 females, 3 males) of adult patients with long-lasting (3+ months) post-viral smell dysfunction followed a 30-day olfactory training protocol with a set of plant-derived essential oils. At baseline and at the end of the treatment, the patients were administered the Assessment of Self-reported Olfactory Functioning (ASOF) questionnaire, an inventory used to measure olfactory dysfunction and health-related quality of life. Results For any of the outcomes assessed with the ASOF scale, a significant improvement from baseline was reported, even though mean value ameliorations were more pronounced for olfactory function per se (Subjective Olfactory Capability: from 3.6 to 5.6 out of 10; Self-Reported capability of Perceiving specific odors: from 1.8 to 3.0 out of 5), rather than for health-related quality of life (Olfactory-Related Quality of life: from 2.9 to 3.9 out of 6). Conclusions It was observed that patients with long-lasting COVID-19-related smell dysfunction improved after a 30-day olfactory training protocol. Further controlled clinical studies would be useful to better investigate the role of olfactory training in patients with postviral smell dysfunction.
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Affiliation(s)
- Davide Donelli
- Servizio di Consulenza in Medicina Integrativa e Complementare, Croce Arancione, 42123 Reggio Emilia, Italy
| | - Michele Antonelli
- Servizio di Consulenza in Medicina Integrativa e Complementare, Croce Arancione, 42123 Reggio Emilia, Italy
| | - Marco Valussi
- European Herbal and Traditional Medicine Practitioners Association (EHTPA), Norwich, UK
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21
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Hummel T, Power Guerra N, Gunder N, Hähner A, Menzel S. Olfactory Function and Olfactory Disorders. Laryngorhinootologie 2023; 102:S67-S92. [PMID: 37130532 PMCID: PMC10184680 DOI: 10.1055/a-1957-3267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The sense of smell is important. This became especially clear to patients with infection-related olfactory loss during the SARS-CoV-2 pandemic. We react, for example, to the body odors of other humans. The sense of smell warns us of danger, and it allows us to perceive flavors when eating and drinking. In essence, this means quality of life. Therefore, anosmia must be taken seriously. Although olfactory receptor neurons are characterized by regenerative capacity, anosmia is relatively common with about 5 % of anosmic people in the general population. Olfactory disorders are classified according to their causes (e. g., infections of the upper respiratory tract, traumatic brain injury, chronic rhinosinusitis, age) with the resulting different therapeutic options and prognoses. Thorough history taking is therefore important. A wide variety of tools are available for diagnosis, ranging from short screening tests and detailed multidimensional test procedures to electrophysiological and imaging methods. Thus, quantitative olfactory disorders are easily assessable and traceable. For qualitative olfactory disorders such as parosmia, however, no objectifying diagnostic procedures are currently available. Therapeutic options for olfactory disorders are limited. Nevertheless, there are effective options consisting of olfactory training as well as various additive drug therapies. The consultation and the competent discussion with the patients are of major importance.
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Affiliation(s)
- T Hummel
- Interdisziplinäres Zentrum Riechen und Schmecken, HNO Klinik, TU Dresden
| | - N Power Guerra
- Rudolf-Zenker-Institut für Experimentelle Chirurgie, Medizinische Universität Rostock, Rostock
| | - N Gunder
- Universitäts-HNO Klinik Dresden, Dresden
| | - A Hähner
- Interdisziplinäres Zentrum Riechen und Schmecken, HNO Klinik, TU Dresden
| | - S Menzel
- Interdisziplinäres Zentrum Riechen und Schmecken, HNO Klinik, TU Dresden
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22
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Shawky MA, Hadeya AM. Platelet-rich Plasma in Management of Anosmia (Single Versus Double Injections). Indian J Otolaryngol Head Neck Surg 2023; 75:1004-1008. [PMID: 37206725 PMCID: PMC10188686 DOI: 10.1007/s12070-023-03553-3] [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: 10/01/2021] [Accepted: 01/26/2023] [Indexed: 02/19/2023] Open
Abstract
Background Anosmia is a common problem with a significant impact on quality of life and increased mortality. People with anosmia may not be able to fully taste foods and may lose interest in eating. This can lead to weight loss or malnutrition. Anosmia can also lead to depression because it may impair one's ability to smell or taste pleasurable foods. Platelet-rich plasma (PRP) is an autologous biologic product with anti-inflammatory and neuroprotective effects. This prospective study evaluated the role of PRP on olfactory neuroregeneration in patients with anosmia and compare the results of single and double injections. Methods 54 patients were included in the study who had olfactory loss greater than 6 months in duration, no evidence of sinonasal inflammatory disease, and no improvement with olfactory training and topical steroids. 27 patients received a single intranasal injection of PRP into the mucosa of the olfactory cleft and 27 patients received a double injections with 3 weeks interval between them. The Q-Sticks Test was administered at the beginning of the study and at 1 and 3 months. Results All patients reported a subjective improvement of their smell shortly after injection but then stabilized. At 3-month post-treatment, 16 patients improved significantly after single injection and 19 patients improved significantly after double injections. There were no adverse outcomes from intranasal PRP injections. Conclusion PRP appears safe for use in the treatment of olfactory loss, and preliminary data suggest possible efficacy, especially for those with persistent loss. Further studies will help determine optimal frequency and duration of use.
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23
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Hummel T, T. Liu D, A. Müller C, A. Stuck B, Welge-Lüssen A, Hähner A. Olfactory Dysfunction: Etiology, Diagnosis, and Treatment. DEUTSCHES ARZTEBLATT INTERNATIONAL 2023; 120:146-154. [PMID: 36647581 PMCID: PMC10198165 DOI: 10.3238/arztebl.m2022.0411] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 06/03/2022] [Accepted: 12/21/2022] [Indexed: 01/18/2023]
Abstract
BACKGROUND Disorders of the sense of smell have received greater attention because of the frequency with which they occur as a symptom of SARS-CoV-2 infection. Olfactory dysfunction can lead to profound reduction in quality of life and may arise from many different causes. METHODS A selective literature review was conducted with consideration of the current version of the guideline issued by the Association of the Scientific Medical Societies in Germany. RESULTS The cornerstones of diagnosis are the relevant medical history and psychophysical testing of olfactory function using standardized validated tests. Modern treatment strategies are oriented on the cause of the dysfunction. While treatment of the underlying inflammation takes precedence in patients with sinunasal dysosmia, olfactory training is the primary treatment option for other forms of the disorder. The prognosis is determined not only by the cause of the olfactory dysfunction and the patient's age, but also by the olfactory performance as measured at the time of diagnosis. CONCLUSION Options for the treatment of olfactory dysfunction are available but limited, depending on the cause. It is therefore important to carry out a detailed diagnostic work-up and keep the patient informed of the expected course and prognosis.
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Affiliation(s)
- Thomas Hummel
- Interdisciplinary Center for Smell and Taste, Department of Otorhinolaryngology, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden
| | - David T. Liu
- Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna General Hospital, Austria
| | - Christian A. Müller
- Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna General Hospital, Austria
| | - Boris A. Stuck
- Department of Otorhinolaryngology, Head and Neck Surgery, Giessen and Marburg University Hospital Ltd., Marburg
| | - Antje Welge-Lüssen
- Interdisciplinary Center for Smell and Taste, Department of Otorhinolaryngology, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden
| | - Antje Hähner
- Department of Otorhinolaryngology, Basel University Hospital, Switzerland
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24
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Ishikawa Y, Suzuki M. Changes in olfactory identification function in total laryngectomy patients - A retrospective study focusing on nasal airflow-inducing maneuver usage, Open Essence misreactions, and odor cluster. Am J Otolaryngol 2023; 44:103778. [PMID: 36586314 DOI: 10.1016/j.amjoto.2022.103778] [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: 12/15/2022] [Accepted: 12/19/2022] [Indexed: 12/27/2022]
Abstract
PURPOSE We aimed to examine how the olfactory identification function of laryngectomy patients is altered by nasal airflow-inducing maneuver (NAIM), a method of olfactory rehabilitation, by analyzing incorrect and correct responses to olfactory identification tests to achieve odor classification. METHODS Olfactory identification test (Open Essence [OE]) was administered to 46 patients who had undergone a total laryngectomy [Start group (NAIM was initiated from this study) = 17; (already) Using group = 19; and Nonuse group = 10]. The tests were immediately performed after the NAIM and after a mean duration of 8 months. RESULTS In the Start group, changes in OE correct and incorrect responses showed a significant increase and decrease in the number of correct (p < 0.01) and "detectable but not recognizable" responses (p < 0.05), respectively. In the Using group, errors related to "same cluster" and "detectable but not recognizable" increased and decreased significantly (p < 0.05), respectively. The Nonuse group showed a trend of demonstrating a relatively lower number of correct responses (p < 0.1). Results of odor classification showed that only "putrefaction and sulfur" did not have any significant positive responses in the Start group. DISCUSSION Evidently, the possibility of capturing changes in olfactory identification function by performing a false response analysis was observed, even if recovery appears to have stalled after long-term use of NAIM. Furthermore, including the "putrefaction and sulfur" cluster in the olfactory rehabilitation of laryngectomy patients and teaching them to consciously sniff "putrefaction and sulfur" in their daily lives is necessary.
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Affiliation(s)
- Yukinobu Ishikawa
- Department of Speech and Hearing Sciences at Ookawa, International University of Health and Welfare, Enokizu, Ookawa, Fukuoka, Japan.
| | - Michi Suzuki
- Department of Rehabilitation, International University of Health and Welfare Narita Hospital, Hatakeda, Narita, Chiba, Japan
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25
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Steen I, Münchow M, Jensen S, Kjaer TW, Waehrens SS, Bredie WLP. Evaluation of a sensory and cognitive online training tool for odor recognition in professional coffee tasters. J SENS STUD 2023. [DOI: 10.1111/joss.12819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Affiliation(s)
- Ida Steen
- Section for Food Design and Consumer Behaviour, Department of Food Science University of Copenhagen Copenhagen Denmark
- CoffeeMind Academy, CoffeeMind Aps Copenhagen Denmark
| | - Morten Münchow
- Section for Food Design and Consumer Behaviour, Department of Food Science University of Copenhagen Copenhagen Denmark
- CoffeeMind Academy, CoffeeMind Aps Copenhagen Denmark
| | | | - Troels W. Kjaer
- Department of Clinical Medicine University of Copenhagen Copenhagen Denmark
| | - Sandra S. Waehrens
- Section for Food Design and Consumer Behaviour, Department of Food Science University of Copenhagen Copenhagen Denmark
| | - Wender L. P. Bredie
- Section for Food Design and Consumer Behaviour, Department of Food Science University of Copenhagen Copenhagen Denmark
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26
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Gossrau G, Zaranek L, Klimova A, Sabatowski R, Koch T, Richter M, Haehner A. Olfactory training reduces pain sensitivity in children and adolescents with primary headaches. FRONTIERS IN PAIN RESEARCH 2023; 4:1091984. [PMID: 36860330 PMCID: PMC9968932 DOI: 10.3389/fpain.2023.1091984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 01/13/2023] [Indexed: 02/15/2023] Open
Abstract
Objective Headache prevalence among children and adolescents has increased over the last few years. Evidence-based treatment options for pediatric headaches remain limited. Research suggests a positive influence of odors on pain and mood. We investigated the effect of repeated exposure to odors on pain perception, headache-related disability, and olfactory function in children and adolescents with primary headaches. Methods Eighty patients with migraine or tension-type headache (mean 13.1 ± 3.29 years) participated, of whom 40 underwent daily olfactory training with individually selected pleasant odors for 3 months and 40 received state-of-the-art outpatient therapy as a control group. At baseline and after a 3-month follow-up, olfactory function [odor threshold; odor discrimination; odor identification; comprehensive Threshold, Discrimination, Identification (TDI) score], mechanical detection and pain threshold (quantitative sensory testing), electrical pain threshold, patient-reported outcomes on headache-related disability [Pediatric Migraine Disability Assessment (PedMIDAS)], pain disability [Pediatric Pain Disability Index (P-PDI)], and headache frequency were assessed. Results Training with odors significantly increased the electrical pain threshold compared to the control group (U = 470.000; z = -3.177; p = 0.001). Additionally, olfactory training significantly increased the olfactory function (TDI score [t(39) = -2.851; p = 0.007], in particular, olfactory threshold, compared to controls (U = 530.500; z = -2.647; p = 0.008). Headache frequency, PedMIDAS, and P-PDI decreased significantly in both groups without a group difference. Conclusions Exposure to odors has a positive effect on olfactory function and pain threshold in children and adolescents with primary headaches. Increased electrical pain thresholds might reduce sensitization for pain in patients with frequent headaches. The additional favorable effect on headache disability without relevant side effects underlines the potential of olfactory training as valuable nonpharmacological therapy in pediatric headaches.
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Affiliation(s)
- Gudrun Gossrau
- Comprehensive Pain Center, University Hospital and Faculty of Medicine Carl Gustav Carus, TU Dresden, Dresden, Germany,Correspondence: Gudrun Gossrau
| | - Laura Zaranek
- Comprehensive Pain Center, University Hospital and Faculty of Medicine Carl Gustav Carus, TU Dresden, Dresden, Germany,Department of Pediatrics, University Hospital and Faculty of Medicine Carl Gustav Carus, TU Dresden, Dresden, Germany
| | - Anna Klimova
- NCT Partner Site Dresden, Institute for Medical Informatics and Biometrics, Faculty of Medicine Carl Gustav Carus, TU Dresden, Dresden, Germany
| | - Rainer Sabatowski
- Comprehensive Pain Center, University Hospital and Faculty of Medicine Carl Gustav Carus, TU Dresden, Dresden, Germany,Departement of Anesthesiology and Intensive Care Medicine, University Hospital and Faculty of Medicine Carl Gustav Carus, TU Dresden, Dresden, Germany
| | - Thea Koch
- Departement of Anesthesiology and Intensive Care Medicine, University Hospital and Faculty of Medicine Carl Gustav Carus, TU Dresden, Dresden, Germany
| | - Matthias Richter
- Department of Pediatrics, University Hospital and Faculty of Medicine Carl Gustav Carus, TU Dresden, Dresden, Germany
| | - Antje Haehner
- Smell & Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
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27
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Winkelmann S, Korth A, Voss B, Nasr MA, Behrend N, Pudszuhn A, Hofmann VM, Schendzielorz P, Maetzler C, Hermes A, Borzikowsky C, Bahmer T, Lieb W, Schreiber S, Stork S, Montellano FA, Witzenrath M, Keil T, Krawczak M, Laudien M, On Behalf Of The Napkon Study Group NSG. Persisting chemosensory dysfunction in COVID-19 - a cross-sectional population-based survey. Rhinology 2023; 61:12-23. [PMID: 36323438 DOI: 10.4193/rhin22.176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND Chemosensory dysfunction (CD) has been reported as a common symptom of SARS-CoV-2 infection, but it is not well understood whether and for how long changes of smell, taste and chemesthesis persist in infected individuals. METHODOLOGY Unselected adult residents of the German federal state of Schleswig-Holstein with Polymerase Chain Reaction (PCR)-test-confirmed SARS-CoV-2 infection were invited to participate in this large cross-sectional study. Data on the medical history and subjective chemosensory function of participants were obtained through questionnaires and visual analogue scales (VAS). Olfactory function (OF) was objectified with the Sniffin Sticks test (SST), including threshold (T), discrimination (D) and identification (I) test as well as summarized TDI score, and compared to that in healthy controls. Gustatory function (GF) was evaluated with the suprathreshold taste strips (TS) test, and trigeminal function was tested with an ampoule containing ammonia. RESULTS Between November 2020 and June 2021, 667 infected individuals (mean age: 48.2 years) were examined 9.1 months, on average, after positive PCR testing. Of these, 45.6% had persisting subjective olfactory dysfunction (OD), 36.2% had subjective gustatory dysfunction (GD). Tested OD, tested GD and impaired trigeminal function were observed in 34.6%, 7.3% and 1.8% of participants, respectively. The mean TDI score of participants was significantly lower compared to healthy subjects. Significant associations were observed between subjective OD and GD, and between tested OD and GD. CONCLUSION Nine months after SARS-CoV-2 infection, OD prevalence is significantly increased among infected members of the general population. Therefore, OD should be included in the list of symptoms collectively defining Long-COVID.
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Affiliation(s)
- S Winkelmann
- Department of Otorhinolaryngology, Head and Neck Surgery, Kiel University, University Medical Centre Schleswig-Holstein, Kiel, Germany
| | - A Korth
- Department of Otorhinolaryngology, Head and Neck Surgery, Kiel University, University Medical Centre Schleswig-Holstein, Kiel, Germany
| | - B Voss
- Department of Otorhinolaryngology, Head and Neck Surgery, Kiel University, University Medical Centre Schleswig-Holstein, Kiel, Germany
| | - M A Nasr
- Department of Otorhinolaryngology, Head and Neck Surgery, Kiel University, University Medical Centre Schleswig-Holstein, Kiel, Germany
| | - N Behrend
- Department of Otorhinolaryngology, Head and Neck Surgery, Kiel University, University Medical Centre Schleswig-Holstein, Kiel, Germany
| | - A Pudszuhn
- Department of Otorhinolaryngology, Head and Neck Surgery, Charity-Universitatsmedizin Berlin, Corporate Member of Freie Universitat Berlin, Humboldt-Universitat zu Berlin and Berlin Institute of Health, Campus Benjamin Franklin, Berlin, Germany
| | - V M Hofmann
- Department of Otorhinolaryngology, Head and Neck Surgery, Charity-Universitatsmedizin Berlin, Corporate Member of Freie Universitat Berlin, Humboldt-Universitat zu Berlin and Berlin Institute of Health, Campus Benjamin Franklin, Berlin, Germany
| | - P Schendzielorz
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Wurzburg, Wurzburg, Germany
| | - C Maetzler
- Neurology Department, University Medical Center Schleswig-Holstein Campus Kiel, Kiel, Germany
| | - A Hermes
- Institute of Epidemiology, Kiel University, University Medical Center Schleswig-Holstein, Kiel, Germany
| | - C Borzikowsky
- Institute of Medical Informatics and Statistics, Kiel University, University Medical Centre Schleswig-Holstein, Kiel, Germany
| | - T Bahmer
- Division of Pneumology, Department of Medicine 1, Kiel University, University Medical Centre Schleswig-Holstein, Kiel, Germany
| | - W Lieb
- Institute of Epidemiology, Kiel University, University Medical Center Schleswig-Holstein, Kiel, Germany
| | - S Schreiber
- Internal Medicine Department I, University Medical Center Schleswig-Holstein Campus Kiel, Kiel, Germany
| | - S Stork
- Comprehensive Heart Failure Center and Dept. Internal Medicine I, University Hospital Wurzburg, Wurzburg, Germany
| | - F A Montellano
- Comprehensive Heart Failure Center and Dept. Internal Medicine I, University Hospital Wurzburg, Wurzburg, Germany; Institute of Clinical Epidemiology and Biometry, University of Wurzburg, Wurzburg, Germany; Department of Neurology, University Hospital Wurzburg, Wurzburg, Germany
| | - M Witzenrath
- Department of Infectious Diseases and Respiratory Medicine, Charity - Universitatsmedizin Berlin, Corporate Member of Freie Universitat Berlin and Humboldt-Universitat zu Berlin, Berlin, Germany
| | - T Keil
- Institute of Clinical Epidemiology and Biometry, University of Wurzburg, Wurzburg, Germany; Institute of Social Medicine, Epidemiology and Health Economics, Charity-Universitatsmedizin Berlin, Berlin, Germany
| | - M Krawczak
- Institute of Medical Informatics and Statistics, Kiel University, University Medical Centre Schleswig-Holstein, Kiel, Germany
| | - M Laudien
- Department of Otorhinolaryngology, Head and Neck Surgery, Kiel University, University Medical Centre Schleswig-Holstein, Kiel, Germany
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28
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Khan AM, Piccirillo J, Kallogjeri D, Piccirillo JF. Efficacy of Combined Visual-Olfactory Training With Patient-Preferred Scents as Treatment for Patients With COVID-19 Resultant Olfactory Loss: A Randomized Clinical Trial. JAMA Otolaryngol Head Neck Surg 2023; 149:141-149. [PMID: 36580304 PMCID: PMC9857399 DOI: 10.1001/jamaoto.2022.4112] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 10/21/2022] [Indexed: 12/30/2022]
Abstract
Importance The number of olfactory dysfunction cases has increased dramatically because of the COVID-19 pandemic. Identifying therapies that aid and accelerate recovery is essential. Objective To determine the efficacy of bimodal visual-olfactory training and patient-preferred scents vs unimodal olfactory training and physician-assigned scents in COVID-19 olfactory loss. Design, Setting, and Participants This was a randomized, single-blinded trial with a 2-by-2 factorial design (bimodal, patient preferred; unimodal, physician assigned; bimodal, physician assigned; unimodal, patient preferred) and an independent control group. Enrollment occurred from February 1 to May 27, 2021. Participants were adults 18 to 71 years old with current olfactory loss defined as University of Pennsylvania Smell Identification Test (UPSIT) score less than 34 for men and less than 35 for women and duration of 3 months or longer. Olfactory loss was initially diagnosed within 2 weeks of COVID-19 infection. Interventions Participants sniffed 4 essential oils for 15 seconds with a 30-second rest in between odors for 3 months. Participants in the physician-assigned odor arms trained with rose, lemon, eucalyptus, and clove. Participants randomized to the patient-preferred arms chose 4 of 24 available scents. If assigned to the bimodal arm, participants were shown digital images of the essential oil they were smelling. Main Outcomes and Measures The primary end point was postintervention change in UPSIT score from baseline; measures used were the UPSIT (validated, objective psychometric test of olfaction), Clinical Global Impressions Impression-Improvement (CGI-I; self-report improvement scale), and Olfactory Dysfunction Outcomes Rating (ODOR; olfaction-related quality-of-life questionnaire). Results Among the 275 enrolled participants, the mean (SD) age was 41 (12) years, and 236 (86%) were female. The change in UPSIT scores preintervention to postintervention was similar between the study arms. The marginal mean difference for change in UPSIT scores preintervention to postintervention between participants randomized to patient-preferred vs physician-assigned olfactory training was 0.73 (95% CI, -1.10 to 2.56), and between participants randomized to bimodal vs unimodal olfactory training was 1.10 (95% CI, -2.92 to 0.74). Five (24%) participants in the control arm had clinically important improvement on UPSIT compared with 18 (53%) in the bimodal, patient-preferred arm for a difference of 29% (95% CI, 4%-54%). Four (19%) participants in the control group self-reported improvement on CGI-I compared with 12 (35%) in the bimodal, patient-preferred arm for a difference of 16% (95% CI, -7% to 39%). The mean change in ODOR score preintervention to postintervention was 11.6 points (95% CI, 9.2-13.9), which was not deemed clinically important nor significantly different between arms. Conclusions and Relevance Based on the change in UPSIT scores, this randomized clinical trial did not show any difference between intervention arms, but when exploring within-patient change in UPSIT as well as self-reported impression of improvement, active interventions were associated with larger improvement than controls with a potential advantage of bimodal intervention. While not definitive, these results suggest that patients with COVID-19 olfactory loss may benefit from bimodal visual-olfactory training with patient-preferred scents. Trial Registration ClinicalTrials.gov Identifier: NCT04710394.
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Affiliation(s)
- Amish M. Khan
- Clinical Outcomes Research Office, Department of Otolaryngology–Head and Neck Surgery, Washington University School of Medicine in St Louis, St Louis, Missouri
| | - Jeffrey Piccirillo
- Clinical Outcomes Research Office, Department of Otolaryngology–Head and Neck Surgery, Washington University School of Medicine in St Louis, St Louis, Missouri
| | - Dorina Kallogjeri
- Clinical Outcomes Research Office, Department of Otolaryngology–Head and Neck Surgery, Washington University School of Medicine in St Louis, St Louis, Missouri
- Statistics Editor, JAMA Otolaryngology–Head & Neck Surgery
| | - Jay F. Piccirillo
- Clinical Outcomes Research Office, Department of Otolaryngology–Head and Neck Surgery, Washington University School of Medicine in St Louis, St Louis, Missouri
- Editor in Chief, JAMA Otolaryngology–Head & Neck Surgery
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The Effect of Traditional Chinese Medicine on Postviral Olfactory Dysfunction: A Systematic Review and Meta-Analysis. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2023; 2023:7448034. [PMID: 36714533 PMCID: PMC9876686 DOI: 10.1155/2023/7448034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 11/06/2022] [Accepted: 12/29/2022] [Indexed: 01/20/2023]
Abstract
Objective The aim of this study is to evaluate the efficacy and safety of traditional Chinese medicine (TCM) for postviral olfactory dysfunction (PVOD). Methods PubMed, EMBASE, Cochrane Central Register of Controlled Trials, China Network Knowledge Infrastructure (CNKI), Chinese Scientific Journal Database (VIP), Chinese Biomedical and Medical (CBM) Database, and Wanfang Database were electronically searched from their inception to July 25, 2022. Two authors independently performed study selection, data extraction, and quality assessment to ensure systematic quality evaluation. Randomized controlled trials (RCTs) comparing TCM with olfactory training and/or drug therapy (OTDT) were included. The outcomes were the effective rate, QOD-P, TDI score, UPSIT score, and adverse effects. Cochrane RoB was the guideline used to evaluate the methodological quality of the included trials. RevMan 5.3 software was used for statistical analysis. Results A total of 6 RCTs involving 467 patients with PVOD were selected. Compared with OTDT, TCM plus OTDT decreased QOD-P (MD = -1.73, 95% CI (-2.40, -1.06), P < 0.0001) but did not increase the effective rate (T&T) (RR = 1.28, 95% CI (0.86, 1.90), P=0.22, I 2 = 61%). Compared with no treatment, TCM seemed to increase the treatment success rate (UPSIT) (RR = 3.17, 95% CI (1.78, 5.65), P < 0.0001, I 2 = 0%), but there was no statistically significant difference in improving the UPSIT score (MD = 3.44, 95% CI (-1.36, 8.24), P=0.16). Compared with drug therapy, TCM plus drug therapy appeared to increase the effective rate (ΔVAS) (RR = 2.36, 95% CI (1.41, 3.94), I 2 = 0%), but there was no statistically significant difference in improving the TDI score (MD = 2.10, 95% CI (-1.99, 6.19), P=0.31). No significant differences in adverse reactions were reported between TCM and OTDT. Conclusion TCM may be an effective treatment for PVOD. With a lack of high-quality RCTs, further large-scale and high-quality RCTs are still warranted.
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Swain S, Panda S, Sahu A, Pani S. Role of topical intranasal corticosteroid for treatment of post-COVID olfactory dysfunction – Our experiences. MATRIX SCIENCE MEDICA 2023. [DOI: 10.4103/mtsm.mtsm_5_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
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Yan CH, Jang SS, Lin HC, Ma Y, Khanwalkar AR, Thai A, Patel ZM. Use of platelet-rich plasma for COVID-19-related olfactory loss: a randomized controlled trial. Int Forum Allergy Rhinol 2022; 13:989-997. [PMID: 36507615 PMCID: PMC9877663 DOI: 10.1002/alr.23116] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Revised: 11/23/2022] [Accepted: 11/28/2022] [Indexed: 12/14/2022]
Abstract
INTRODUCTION The current study evaluated the use of platelet-rich plasma (PRP), an autologous blood product with supraphysiologic concentrations of growth factors, in the treatment of prolonged coronavirus disease 2019 (COVID-19)-related smell loss. METHODS This multi-institutional, randomized controlled trial recruited patients with COVID-19 who had objectively measured smell loss (University of Pennsylvania Smell Identification Test [UPSIT] ≤ 33) between 6 and 12 months. Patients were randomized to three intranasal injections of either PRP or sterile saline into their olfactory clefts. The primary outcome measure was change in Sniffin' Sticks score (threshold, discrimination, and identification [TDI]) from baseline. The secondary end point measures included responder rate (achievement of a clinically significant improvement, ≥5.5 points TDI), change in individual TDI olfaction scores, and change in subjective olfaction via a visual analog scale. RESULTS A total of 35 patients were recruited and 26 completed the study. PRP treatment resulted in a 3.67-point (95% CI: 0.05-7.29, p = 0.047) greater improvement in olfaction compared with the placebo group at 3 months and a higher response rate (57.1% vs 8.3%, odds ratio 12.5 [95% exact bootstrap confidence interval, 2.2-116.7]). There was a greater improvement in smell discrimination following PRP treatment compared with placebo but no difference in smell identification or threshold. There was no difference in subjective scores between PRP and placebo. No adverse effects were reported. CONCLUSION Olfactory function following COVID-19 can improve spontaneously after 6 months and can improve to a greater extent with PRP injection. These data build on the promise of PRP to be a safe potential treatment option for patients with COVID-19-related smell loss, and larger-powered studies will help further assess its efficacy.
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Affiliation(s)
- Carol H. Yan
- Department of OtolaryngologyHead and Neck SurgeryUniversity of CaliforniaSan Diego School of MedicineLa JollaCaliforniaUSA
| | - Sophie S. Jang
- Department of OtolaryngologyHead and Neck SurgeryUniversity of CaliforniaSan Diego School of MedicineLa JollaCaliforniaUSA
| | - Hung‐Fu C. Lin
- Department of OtolaryngologyHead and Neck SurgeryStanford University School of MedicineStanfordCaliforniaUSA
| | - Yifei Ma
- Department of OtolaryngologyHead and Neck SurgeryStanford University School of MedicineStanfordCaliforniaUSA
| | - Ashoke R. Khanwalkar
- Department of OtolaryngologyHead and Neck SurgeryStanford University School of MedicineStanfordCaliforniaUSA
| | - Anthony Thai
- Department of OtolaryngologyHead and Neck SurgeryStanford University School of MedicineStanfordCaliforniaUSA
| | - Zara M. Patel
- Department of OtolaryngologyHead and Neck SurgeryStanford University School of MedicineStanfordCaliforniaUSA
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Koyama S, Mori E, Ueha R. Insight into the mechanisms of olfactory dysfunction by COVID-19. Auris Nasus Larynx 2022:S0385-8146(22)00230-9. [PMID: 36529610 PMCID: PMC9731926 DOI: 10.1016/j.anl.2022.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 11/29/2022] [Accepted: 12/06/2022] [Indexed: 12/13/2022]
Abstract
One of the unique symptoms of COVID-19 is chemosensory dysfunction. Almost three years since the beginning of the pandemic of COVID-19, there have been many studies on the symptoms, progress, and possible causes, and also studies on methods that may facilitate recovery of the senses. Studies have shown that some people recover their senses even within a couple of weeks whereas there are other patients that fail to recover chemosensory functions fully for several months and some never fully recover. Here we summarize the symptoms and the progress, and then review the papers on the causation as well as the treatments that may help facilitate the recovery of the symptoms. Depending on the differences in the levels of severity and the locations where the main pathological venues are, what is most effective in facilitating recovery can vary largely across patients and thus may require individualized strategies for each patient. The goal of this paper is to provide some thoughts on these choices depending on the differences in the causes and severity.
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Affiliation(s)
- Sachiko Koyama
- Indiana University, School of Medicine, Department of Medicine, United States,Correspondence author at: Indiana University, Richard L. Roudebush VA Medical Center, 1481 W Tenth St., Indianapolis, IN, 46202, United States
| | - Eri Mori
- Department of Otorhinolaryngology, Jikei University, School of Medicine, Japan
| | - Rumi Ueha
- Swallowing Center, The University of Tokyo Hospital, Japan,Department of Otolaryngology, Head and Neck Surgery, Faculty of Medicine, the University of Tokyo, Japan
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Peng H, Yang C, Jian F, Wu S. Study on a Flexible Odor-Releasing Device for Olfactory Training. SENSORS (BASEL, SWITZERLAND) 2022; 22:9519. [PMID: 36502219 PMCID: PMC9741058 DOI: 10.3390/s22239519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 11/22/2022] [Accepted: 12/03/2022] [Indexed: 06/17/2023]
Abstract
Olfactory training has been shown to be effective in treating olfactory dysfunction. However, there are hardly any devices that can regularly and quantificationally release odors for olfactory training. A new odor-releasing device, which is low-cost, customizable, semi-automatic, and flexible, was developed in this study. The operation of the device can be easily achieved by the examiner, or even by the participant, simply by pressing a few buttons. A controller system with 15 individual relays was employed to master the working logic for the whole process. The device allows the examiner to isolate from the participants using the Bluetooth module in the control board. The odorants and their concentrations stored in the scent bottles can be customized by the specific requirements of different participants. The odors for training are provided by ultrasonic atomizers, which have simple structures, but powerful features. The flow rates of the odors can also be controlled by altering the rotation speed of the fans. Final experiments on practical odor generation further proved the potential of the developed device for olfactory training. More attention should be paid to the improvements of odor generation devices for olfactory training.
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Affiliation(s)
- Huisheng Peng
- School of Aeronautics and Astronautics, Sun Yat-sen University, Guangzhou 510275, China
| | - Cheng Yang
- School of Aeronautics and Astronautics, Sun Yat-sen University, Guangzhou 510275, China
| | - Feitong Jian
- Department of Otorhinolaryngology Head and Neck Surgery, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou 510630, China
| | - Shuo Wu
- Department of Otorhinolaryngology Head and Neck Surgery, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou 510630, China
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Kapoor D, Verma N, Gupta N, Goyal A. Post Viral Olfactory Dysfunction After SARS-CoV-2 Infection: Anticipated Post-pandemic Clinical Challenge. Indian J Otolaryngol Head Neck Surg 2022; 74:4571-4578. [PMID: 34249668 PMCID: PMC8260324 DOI: 10.1007/s12070-021-02730-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Accepted: 06/27/2021] [Indexed: 02/07/2023] Open
Abstract
Persistent olfactory dysfunction (OD) is the second most common symptom of post coronavirus disease-19 (COVID-19) now being termed long-COVID. Its prevalence after recovery from COVID-19 is estimated to be 12% after nearly 6 months of follow-up. It thus becomes imperative for the treating clinicians to update themselves with the pathophysiology of this post COVID disability as well as the tools for diagnosis and the available treatment options. A systematic literature search was performed as per PRISMA guidelines in MEDLINE, Cochrane Library, LILACS, Google Scholar, ClinicalTrials.gov, and medRxiv databases. The keywords used were covid-19, Olfactory Disorders, Smell, Anosmia, PVOD, Post Viral Olfactory Disorders, post-covid and post haul. All articles were studied for definition, mechanism, diagnostic tests and treatment options for post COVID OD. 33 published articles and 8 ongoing trials were found relevant and included after full-text review. SARS-CoV-2 can cause conductive, neural and central OD. Olfactory evaluation can be done both subjectively (visual analogue scale) and objectively (Sniffin' sticks, Sinonasal Outcome Test, University of Pennsylvania Smell Identification Test and modified Davidson's alcohol sniff test). They can be used to detect and follow-up patients. Despite several on-going clinical trials, the most reliable and advisable treatment option available till date is olfactory training.
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Affiliation(s)
- Dhruv Kapoor
- Department of Otorhinolaryngology, University College of Medical Sciences, Delhi, India
| | - Neha Verma
- Department of Otorhinolaryngology, University College of Medical Sciences, Delhi, India ,Present Address: Department of Otorhinolaryngology, Guru Teg Bahadur Hospital, Ward 25, Delhi, 110 095 India
| | - Neelima Gupta
- Department of Otorhinolaryngology, University College of Medical Sciences, Delhi, India
| | - Arun Goyal
- Department of Otorhinolaryngology, University College of Medical Sciences, Delhi, India
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Liu DT, Prem B, Sharma G, Kaiser J, Besser G, Mueller CA. Eating behavior in patients with smell loss. Front Nutr 2022; 9:993639. [DOI: 10.3389/fnut.2022.993639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 10/20/2022] [Indexed: 11/10/2022] Open
Abstract
BackgroundThe objective of this study was to determine how clinical characteristics and validated quality of life (QoL)-measures are associated with eating behavior in patients with olfactory dysfunction (OD).MethodsFor this cross-sectional study, 150 OD patients of different causes were retrospectively recruited. Olfactory function was measured using the Sniffin’ Sticks (TDI), while olfactory-related QoL was evaluated with the Questionnaire of OD negative and positive statements (QOD-NS and QOD-PS). The importance of olfaction was measured using the Importance of Olfaction Questionnaire (IOQ). The Dutch Eating Behavior Questionnaire (DEBQ) assessed eating behavior based on emotional, external, and restrained eating. Associations were sought between eating behavior metrics (as dependent variables) with clinical characteristics and olfactory-related outcome measures.ResultsEmotional, external, and restrained eating behavior deviating from normative standards were reported in 54%, 71.3%, and 68% of patients, respectively. Multivariate regression modeling revealed that emotional eating was associated with age (ß = –0.227, p = 0.032), the body mass index (BMI, ß = 0.253, p = 0.005), the TDI (ß = 0.190, p = 0.046), and the QOD-NS (ß = 0.203, p = 0.049). External eating was associated with OD duration (ß = 0.291, p = 0.005), the TDI (ß = 0.225, p = 0.018), the QOD-PS (ß = –0.282, p = 0.008), and the IOQ (ß = 0.277, p = 0.004). Restrained eating was associated with age (ß = 0.216, p = 0.033), the BMI (ß = 0.257, p = 0.003), male gender (ß = –0.263, p = 0.002), and the IOQ (ß = 0.332, p < 0.001).ConclusionClinical characteristics and olfactory outcome measures differentially impact eating styles in OD patients. Our study’s results highlight the importance of considering unfavorable changes in eating behavior during clinical counseling.
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Vaswani PA, Morley JF, Jennings D, Siderowf A, Marek K, Marek K, Seibyl J, Siderowf A, Stern M, Russell D, Sethi K, Frank S, Simuni T, Hauser R, Ravina B, Richards I, Liang G, Adler C, Saunders-Pullman R, Evatt ML, Lai E, Subramanian I, Hogarth P, Chung K. Serial olfactory testing for the diagnosis of prodromal Parkinson's disease in the PARS study. Parkinsonism Relat Disord 2022; 104:15-20. [PMID: 36194902 DOI: 10.1016/j.parkreldis.2022.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 08/28/2022] [Accepted: 09/11/2022] [Indexed: 01/09/2023]
Abstract
BACKGROUND The Parkinson Associated Risk Syndrome (PARS) study was designed to evaluate whether screening with olfactory testing and dopamine transporter (DAT) imaging could identify participants at risk for developing Parkinson's disease (PD). OBJECTIVE Hyposmia on a single test has been associated with increased risk of PD, but, taken alone, lacks specificity. We evaluated whether repeating olfactory testing improves the diagnostic characteristics of this screening approach. METHODS Participants completed up to 10 years of clinical and imaging evaluations in the PARS cohort. Olfaction was assessed with the University of Pennsylvania Smell Identification Test at baseline and on average 1.4 years later. Multiple logistic regression and Cox proportional hazards regression were used to estimate the hazard of development of clinical PD or abnormal DAT imaging. RESULTS Of 186 participants who were initially hyposmic, 28% reverted to normosmia on repeat testing (reverters). No initially normosmic subjects and only 2% of reverters developed DAT imaging progression or clinical PD, compared to 29% of subjects with persistent hyposmia who developed abnormal DAT and 20% who developed clinical PD. The relative risk of clinical conversion to PD was 8.3 (95% CI:0.92-75.2, p = 0.06) and of abnormal DAT scan was 12.5 (2.4-156.2, p = 0.005) for persistent hyposmia, compared to reversion. CONCLUSIONS Persistent hyposmia on serial olfactory testing significantly increases the risk of developing clinical PD and abnormal DAT imaging, compared to hyposmia on a single test. Repeat olfactory testing may be an efficient and cost-effective strategy to improve identification of at-risk patients for early diagnosis and disease modification studies.
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Affiliation(s)
- Pavan A Vaswani
- Parkinson's Disease Research, Education and Clinical Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA, USA; Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| | - James F Morley
- Parkinson's Disease Research, Education and Clinical Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA, USA; Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Danna Jennings
- Institute for Neurodegenerative Disorders, New Haven, CT, USA
| | - Andrew Siderowf
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Kenneth Marek
- Institute for Neurodegenerative Disorders, New Haven, CT, USA
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Muacevic A, Adler JR, Alrajhi A, Khan MF, Babkour A. Prevalence, Patterns, Prognosis, and Psychosocial Impact of Olfactory and Gustative Dysfunctions Among Saudi COVID-19 Patients. Cureus 2022; 14:e31743. [PMID: 36569668 PMCID: PMC9770517 DOI: 10.7759/cureus.31743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/18/2022] [Indexed: 11/22/2022] Open
Abstract
Objective The objective of this study is to estimate the prevalence of olfactory and gustative dysfunctions (OGD) and analyze their pattern and psychosocial impact among COVID-19 patients. Method A cross-sectional study was conducted among 194 confirmed COVID-19 cases at Al-Noor Specialist Hospital between 1 September 2020 and 30 September 2021. A questionnaire was translated and modified from another study to collect the baseline demographic data and medical history; characterization of smell and taste loss separately, including timing, level, practices or treatment used to restore, recovery, and symptom duration; and the psychological impact of OGD using six items to explore the multidimensional impact, such as daily activity, job performance, and social life. A four-point Likert-type agreement scale was used, and an impact score was calculated. Result As high as 97.4% and 94.8% of the participants declared having experienced a certain level of olfactory and gustative dysfunction, respectively. In the majority of these cases, the dysfunction occurred after the acute phase of the disease and persisted less than one month after onset. Social life (78.4%), job performance (64.4%), and daily life activities (42.8%) were the most frequently impacted dimensions, and 32% of the participants were deemed to have experienced a high psychosocial impact. Younger participants, females, and certain job categories were significantly more impacted than their counterparts. Conclusion OGDs are highly frequent in COVID-19 patients. They are described to be relatively severe and have frequent psychosocial impacts, notably in females and the younger age category. Further research is warranted to determine efficacious preventive and management strategies in order to prevent their long-term impact on wellbeing.
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Two-Year Follow-Up on Chemosensory Dysfunction and Adaptive Immune Response after Infection with SARS-CoV-2 in a Cohort of 44 Healthcare Workers. LIFE (BASEL, SWITZERLAND) 2022; 12:life12101556. [PMID: 36294991 PMCID: PMC9605261 DOI: 10.3390/life12101556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 09/17/2022] [Accepted: 09/29/2022] [Indexed: 11/05/2022]
Abstract
Persistent chemosensory dysfunction (PCD) is a common symptom of long-COVID. Chemosensory dysfunction (CD) as well as SARS-CoV-2-specific antibody levels and CD8+ T-cell immunity were investigated in a cohort of 44 healthcare workers up to a median of 721 days after a positive PCR test. CD was assessed using questionnaires and psychophysical screening tests. After 721 days, 11 of 44 (25%) participants reported PCD, with five describing an impaired quality of life. One participant reported hyperosmia (increased sense of smell). The risk of PCD at 721 days was higher for participants reporting qualitative changes (parosmia (altered smell), dysgeusia (altered taste), or phantosmia (hallucination of smell)) during initial infection than in those with isolated quantitative losses during the first COVID-19 infection (62.5% vs. 7.1%). The main recovery rate occurred within the first 100 days and did not continue until follow-up at 2 years. No correlation was found between antibody levels and CD, but we observed a trend of a higher percentage of T-cell responders in participants with CD. In conclusion, a significant proportion of patients suffer from PCD and impaired quality of life 2 years after initial infection. Qualitative changes in smell or taste during COVID-19 pose a higher risk for PCD.
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Pieniak M, Oleszkiewicz A, Avaro V, Calegari F, Hummel T. Olfactory training - Thirteen years of research reviewed. Neurosci Biobehav Rev 2022; 141:104853. [PMID: 36064146 DOI: 10.1016/j.neubiorev.2022.104853] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 08/26/2022] [Accepted: 08/30/2022] [Indexed: 10/14/2022]
Abstract
The sense of smell is interrelated with psychosocial functioning. Olfactory disorders often decrease quality of life but treatment options for people with olfactory loss are limited. Additionally, olfactory loss accompanies and precedes psychiatric and neurodegenerative diseases. Regular, systematic exposure to a set of odors, i.e., olfactory training (OT) has been offered for rehabilitation of the sense of smell in clinical practice. As signals from the olfactory bulb are directly projected to the limbic system it has been also debated whether OT might benefit psychological functioning, i.e., mitigate cognitive deterioration or improve emotional processing. In this review we synthesize key findings on OT utility in the clinical practice and highlight the molecular, cellular, and neuroanatomical changes accompanying olfactory recovery in people with smell loss as well as in experimental animal models. We discuss how OT and its modifications have been used in interventions aiming to support cognitive functions and improve well-being. We delineate main methodological challenges in research on OT and suggest areas requiring further scientific attention.
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Affiliation(s)
- Michal Pieniak
- Smell and Taste Clinic, Technische Universitat Dresden, Dresden, Germany; University of Wrocław, Faculty of Historical and Pedagogical Sciences, Institute of Psychology, Wroclaw, Poland.
| | - Anna Oleszkiewicz
- Smell and Taste Clinic, Technische Universitat Dresden, Dresden, Germany; University of Wrocław, Faculty of Historical and Pedagogical Sciences, Institute of Psychology, Wroclaw, Poland
| | - Vittoria Avaro
- CRTD-Center for Regenerative Therapies Dresden, Technische Universität Dresden, Dresden, Germany
| | - Federico Calegari
- CRTD-Center for Regenerative Therapies Dresden, Technische Universität Dresden, Dresden, Germany
| | - Thomas Hummel
- Smell and Taste Clinic, Technische Universitat Dresden, Dresden, Germany
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Leon M, Woo CC. Olfactory loss is a predisposing factor for depression, while olfactory enrichment is an effective treatment for depression. Front Neurosci 2022; 16:1013363. [PMID: 36248633 PMCID: PMC9558899 DOI: 10.3389/fnins.2022.1013363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Accepted: 09/08/2022] [Indexed: 11/13/2022] Open
Abstract
The loss of olfactory stimulation correlates well with at least 68 widely differing neurological disorders, including depression, and we raise the possibility that this relationship may be causal. That is, it seems possible that olfactory loss makes the brain vulnerable to expressing the symptoms of these neurological disorders, while daily olfactory enrichment may decrease the risk of expressing these symptoms. This situation resembles the cognitive reserve that is thought to protect people with Alzheimer’s neuropathology from expressing the functional deficit in memory through the cumulative effect of intellectual stimulation. These relationships also resemble the functional response of animal models of human neurological disorders to environmental enrichment, wherein the animals continue to have the induced neuropathology, but do not express the symptoms as they do in a standard environment with restricted sensorimotor stimulation.
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Affiliation(s)
- Michael Leon
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
- Center for the Neurobiology of Learning and Memory, Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA, United States
- *Correspondence: Michael Leon,
| | - Cynthia C. Woo
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
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Lechien JR, Vaira LA, Saussez S. Effectiveness of olfactory training in COVID-19 patients with olfactory dysfunction: a prospective study. Eur Arch Otorhinolaryngol 2022; 280:1255-1263. [PMID: 36153785 PMCID: PMC9510568 DOI: 10.1007/s00405-022-07665-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 09/16/2022] [Indexed: 02/07/2023]
Abstract
OBJECTIVES To investigate effectiveness of olfactory training (OT) in COVID-19 patients with persistent olfactory dysfunction (OD). METHODS From March 2020 to March 2022, COVID-19 patients with OD were prospectively followed in three European medical centers for a period of 18 months. A standardized OT protocol were recommended to patients. Patient-reported outcome questionnaires and psychophysical evaluations were used to evaluate olfaction at baseline, 6, 12, and 18 months after the start of OT. The evolution of olfactory outcome was compared according to the adherence to the OT protocol. RESULTS Fifty-seven patients completed the evaluations. Thirty-two patients fully adhered to the OT, while 25 did not adhere. The psychophysical scores significantly improved from baseline to 6-month post-infection in both groups. In the OT group, the psychophysical scores continued to significantly improve from 6 to 12 months after the start of OT (p = 0.032). The mean duration of OT was 15.4 weeks. The mean delay of patient recovery perception was comparable between groups (27.4 weeks). The occurrence of cacosmia (35.1%) and parosmia (43.9%) throughout the follow-up period was comparable between groups. There proportion of phantosmia was higher in training (34.4%) compared with no-OT (16.0%; p = 0.007) group. The baseline Sniffin'Sticks tests was positively associated with the 6-month Sniffin'Sticks tests (rs = 0.685; p < 0.001) and negatively associated with the time of recovery (rs = - 0.369; p = 0.034). CONCLUSIONS The adherence to an OT protocol was associated with better mid-term improvement of psychophysical scores. Future large-cohort randomized-controlled studies are needed to confirm the effectiveness of OT in COVID-19 patients.
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Affiliation(s)
- Jerome R. Lechien
- Department of Otolaryngology, Polyclinic of Poitiers, Elsan, Poitiers, France ,grid.8364.90000 0001 2184 581XDepartment of Human Anatomy and Experimental Oncology, Faculty of Medicine, UMONS Research Institute for Health Sciences and Technology, University of Mons (UMons), Mons, Belgium ,grid.12832.3a0000 0001 2323 0229Department of Otorhinolaryngology and Head and Neck Surgery, Foch Hospital, School of Medicine, UFR Simone Veil, Université Versailles Saint-Quentin-en-Yvelines (Paris Saclay University), Paris, France ,grid.490660.dDepartment of Otorhinolaryngology and Head and Neck Surgery, EpiCURA Hospital, Baudour, Belgium
| | - Luigi A. Vaira
- grid.11450.310000 0001 2097 9138Maxillofacial Surgery Operative Unit, Department of Medical, Surgical and Experimental Sciences, University of Sassari, Sassari, Italy ,grid.11450.310000 0001 2097 9138Biomedical Science Department, PhD School of Biomedical Science, University of Sassari, Sassari, Italy
| | - Sven Saussez
- grid.8364.90000 0001 2184 581XDepartment of Human Anatomy and Experimental Oncology, Faculty of Medicine, UMONS Research Institute for Health Sciences and Technology, University of Mons (UMons), Mons, Belgium ,grid.490660.dDepartment of Otorhinolaryngology and Head and Neck Surgery, EpiCURA Hospital, Baudour, Belgium
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Mendes Paranhos AC, Nazareth Dias ÁR, Machado da Silva LC, Vieira Hennemann Koury G, de Jesus Sousa E, Cerasi AJ, Souza GS, Simões Quaresma JA, Magno Falcão LF. Sociodemographic Characteristics and Comorbidities of Patients With Long COVID and Persistent Olfactory Dysfunction. JAMA Netw Open 2022; 5:e2230637. [PMID: 36074464 PMCID: PMC9459661 DOI: 10.1001/jamanetworkopen.2022.30637] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
IMPORTANCE Determining the characteristics, type, and severity of olfactory dysfunction in patients with long COVID is important for the prognosis and potential treatment of the affected population. OBJECTIVE To describe the sociodemographic and clinical features of patients with long COVID who develop persistent olfactory dysfunction. DESIGN, SETTING, AND PARTICIPANTS This cross-sectional study, conducted at a rehabilitation center at a public university in the Amazon region of Brazil between September 9, 2020, and October 20, 2021, comprised 219 patients with long COVID and self-reported neurologic symptoms. Of these 219 patients, 139 received a diagnosis of chronic olfactory dysfunction, as confirmed by the Connecticut Chemosensory Clinical Research Center (CCCRC) test. EXPOSURE Clinical diagnosis of long COVID. MAIN OUTCOMES AND MEASURES Electronic case report forms were prepared for the collection of sociodemographic and clinical data. Patients' sense of smell was evaluated via a CCCRC test, and the association of olfactory dysfunction with aspects of daily life was recorded using a questionnaire. RESULTS Of the 219 patients included in the study, 164 (74.9%) were women, 194 (88.6%) were between 18 and 59 years of age (mean [SD] age, 43.2 [12.9] years), 206 (94.1%) had more than 9 years of education, and 115 (52.5%) had a monthly income of up to US $192.00. In the study group, 139 patients (63.5%) had some degree of olfactory dysfunction, whereas 80 patients (36.5%) had normosmia. Patients with olfactory dysfunction had a significantly longer duration of long COVID symptoms than those in the normosmia group (mean [SD], 242.7 [101.9] vs 221.0 [97.5] days; P = .01). Among patients with anosmia, there was a significant association between olfactory dysfunction and daily activities, especially in terms of impairment in hazard detection (21 of 31 patients [67.7%]), personal hygiene (21 of 31 patients [67.7%]), and food intake (21 of 31 patients [67.7%]). Univariable logistic regression analyses found that ageusia symptoms were associated with the occurrence of olfactory dysfunction (odds ratio [OR], 11.14 [95% CI, 4.76-26.07]; P < .001), whereas headache (OR, 0.41 [95% CI, 0.22-0.76]; P < .001) and sleep disorders (OR, 0.48 [95% CI, 0.26-0.92]; P = .02) showed an inverse association with the occurrence of olfactory dysfunction. CONCLUSIONS AND RELEVANCE Olfactory dysfunction is one of the most important long-term neurologic symptoms of COVID-19, with the highest prevalence seen among women, adults, and outpatients. Patients with olfactory dysfunction may experience persistent severe hyposmia or anosmia more than 1 year from the onset of symptoms, suggesting the possibility of the condition becoming a permanent sequela.
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Affiliation(s)
- Alna Carolina Mendes Paranhos
- Tropical Medicine Center, Federal University of Pará, Belém, Brazil
- Biological and Health Center, Pará State University, Belém, Brazil
| | | | | | | | | | - Antônio José Cerasi
- Biological Science Center, Federal University of Pará, Belém, Brazil
- Cosmopolita College, Belém, Brazil
| | - Givago Silva Souza
- Tropical Medicine Center, Federal University of Pará, Belém, Brazil
- Biological Science Center, Federal University of Pará, Belém, Brazil
| | - Juarez Antônio Simões Quaresma
- Tropical Medicine Center, Federal University of Pará, Belém, Brazil
- Biological and Health Center, Pará State University, Belém, Brazil
| | - Luiz Fábio Magno Falcão
- Biological and Health Center, Pará State University, Belém, Brazil
- University of São Paulo, São Paulo, Brazil
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Di Stadio A, D’Ascanio L, Vaira LA, Cantone E, De Luca P, Cingolani C, Motta G, De Riu G, Vitelli F, Spriano G, De Vincentiis M, Camaioni A, La Mantia I, Ferreli F, Brenner MJ. Ultramicronized Palmitoylethanolamide and Luteolin Supplement Combined with Olfactory Training to Treat Post-COVID-19 Olfactory Impairment: A Multi-Center Double-Blinded Randomized Placebo- Controlled Clinical Trial. Curr Neuropharmacol 2022; 20:2001-2012. [PMID: 35450527 PMCID: PMC9886808 DOI: 10.2174/1570159x20666220420113513] [Citation(s) in RCA: 46] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 03/23/2022] [Accepted: 04/09/2022] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Olfactory training is the only evidence-based treatment for post-viral olfactory dysfunction. Smell disorders after SARS-CoV-2 infection have been attributed to neuroinflammatory events within the olfactory bulb and the central nervous system. Therefore, targeting neuroinflammation is one potential strategy for promoting recovery from post-COVID-19 chronic olfactory dysfunction. Palmitoylethanolamide and luteolin (PEA-LUT) are candidate antiinflammatory/ neuroprotective agents. OBJECTIVE To investigate recovery of olfactory function in patients treated with PEA-LUT oral supplements plus olfactory training versus olfactory training plus placebo. METHODS Multicenter double-blinded randomized placebo-controlled clinical trial was held. Eligible subjects had prior COVID-19 and persistent olfactory impairment >6 months after follow-up SARS-CoV-2 negative testing, without prior history of olfactory dysfunction or other sinonasal disorders. Participants were randomized to daily oral supplementation with ultramicronized PEA-LUT 770 mg plus olfactory training (intervention group) or olfactory training with placebo (control). Sniffin' Sticks assessments were used to test the patients at baseline and 90 days. RESULTS A total of 185 patients, including intervention (130) and control (55) were enrolled. The intervention group showed significantly greater improvement in olfactory threshold, discrimination, and identification scores compared to controls (p=0.0001). Overall, 92% of patients in the intervention group improved versus 42% of controls. Magnitude of recovery was significantly greater in the intervention group versus control (12.8 + 8.2 versus mean 3.2 + 3), with >10-fold higher prevalence of anosmia in control versus intervention groups at the 90-day endpoint. CONCLUSION Among individuals with olfactory dysfunction post-COVID-19, combining PEA-LUT with olfactory training resulted in greater recovery of smell than olfactory training alone.
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Affiliation(s)
- Arianna Di Stadio
- Address correspondence to this author at the University of Catania, Otolaryngology Department, Catania, Italy; E-mail:
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Improving taste sensitivity in healthy adults using taste recall training: a randomized controlled trial. Sci Rep 2022; 12:13849. [PMID: 35974039 PMCID: PMC9379898 DOI: 10.1038/s41598-022-18255-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 08/08/2022] [Indexed: 11/16/2022] Open
Abstract
Although many patients suffer from taste disorder, methods to improve taste sensitivity are limited. To develop a taste recall training method to improve the perception of taste, 42 healthy individuals were randomly assigned to either the training or the control group. Using the filter paper disc method, participants in the training group were asked to match the four tastes (sweetness, saltiness, sourness, and bitterness) between those of taste recognition thresholds and those of a one-step higher concentration until they get them right. Then, they were asked to match the four tastes between those of one-step lower and one-step higher in concentration from their taste recognition thresholds until they get them right. Finally, they were asked to match the four tastes between those of one-step lower concentration and those of their taste recognition thresholds until they get them right. This training was repeated until perfectly matched. The taste recall training program led to a lowered taste recognition threshold in healthy adults for each taste quality, suggesting the improvement of taste sensitivity. This lowered threshold for each taste was observed with each additional training session. We conclude that this taste recall training method might be a therapeutic approach for treating taste disorder.
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Nag AK, Saltagi AK, Saltagi MZ, Wu AW, Higgins TS, Knisely A, Ting JY, Illing EA. Management of Post-Infectious Anosmia and Hyposmia: A Systematic Review. Ann Otol Rhinol Laryngol 2022:34894221118186. [PMID: 35959948 DOI: 10.1177/00034894221118186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Anosmia and hyposmia significantly affect patients' quality of life and have many etiologies, including trauma, inflammatory conditions including chronic rhinosinusitis, neoplasm, and viral infections, such as rhinovirus and SARS-CoV-2. OBJECTIVE Our purpose was to establish whether a consensus exists regarding optimal management of olfactory dysfunction and to provide insight into the treatment of anosmia in the current climate of increased prevalence secondary to COVID-19. Thus, we aimed to systematically review the literature on the management of non-Chronic-rhinosinusitis- related anosmia/hyposmia. METHODS PubMed, EMBASE, and Cochrane databases were searched for articles published since January 1990 using terms combined with Medical Subject Headings (MeSH). We included articles evaluating management of anosmia and hyposmia written in the English language, with original data, a minimum of 3 months of follow-up except for COVID-related studies, at least 2 patients, and well-defined and measurable outcomes. RESULTS A total of 3013 unique titles were returned upon the initial search. Of these, 297 abstracts were examined, yielding 19 full texts meeting inclusion criteria (8 with level 1 evidence, 3 with level 2, 1 with level 3, and 7 with level 4). The studies included a total of 1522 subjects, with follow up ranging from 3 to 72 months, with an exception for COVID related studies. Endpoints were based on clinically significant improvements of olfactory functions as measured through validated smell tests. Treatments with the most robust data were intranasal corticosteroids and olfactory training. CONCLUSION The literature on the treatment of anosmia and hyposmia includes randomized trials showing the efficacy of a few modalities. While further research is needed to expand therapeutic options for this debilitating condition, the current literature supports the use of olfactory training and topical corticosteroids.
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Affiliation(s)
- Amit K Nag
- Department of Otolaryngology-Head and Neck Surgery, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Abdul K Saltagi
- Indiana University School of Medicine, Indianapolis, IN, USA
| | - Mohamad Z Saltagi
- Indiana University School of Medicine, Indianapolis, IN, USA.,Department of Otolaryngology-Head and Neck Surgery, Indiana University Health, Indianapolis, IN, USA
| | - Arthur W Wu
- Cedars-Sinai Division of Otolaryngology, Los Angeles, CA, USA
| | - Thomas S Higgins
- Department of Otolaryngology-Head and Neck Surgery, University of Louisville, Louisville, KY, USA.,Kentuckiana Ear, Nose & Throat, Louisville, KY, USA
| | - Anna Knisely
- Department of Otolaryngology, Head and Neck Surgery, Swedish Medical Center, Seattle, WA, USA
| | - Jonathan Y Ting
- Indiana University School of Medicine, Indianapolis, IN, USA.,Department of Otolaryngology-Head and Neck Surgery, Indiana University Health, Indianapolis, IN, USA
| | - Elisa A Illing
- Indiana University School of Medicine, Indianapolis, IN, USA.,Department of Otolaryngology-Head and Neck Surgery, Indiana University Health, Indianapolis, IN, USA
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Ogawa T, Matsumoto K, Tojima I, Kikuoka H, Hira D, Shimizu T. Therapeutic Potential of Valproic Acid for Postviral Olfactory Dysfunction: A Single-Arm Pilot Study. Ann Otol Rhinol Laryngol 2022; 132:709-714. [PMID: 35833237 DOI: 10.1177/00034894221111245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVES Although some patients with postviral olfactory dysfunction (PVOD) recover spontaneously, many others are left with the degree of smell loss and there are no established drugs for the treatment of patients with PVOD. Valproic acid (VPA) has been widely used for the treatment of epilepsy. Its potential neuroregenerative effects have been shown via animal studies. This is the first study to treat PVOD patients with VPA. This open-label, single-arm, phase II study was conducted to investigate the effects of VPA in patients with PVOD. METHODS The patients received oral tablets of VPA 200 mg twice a day for 24 weeks. In total, 11 patients with PVOD were recruited. Oder scores of recognition and detection threshold (measured with a T&T olfactometer), and visual analog scale were examined during the treatment. RESULTS All odor scores significantly improved over time. Although the mean duration of olfactory dysfunction in this study was 11.5 months, both odor recognition threshold and odor detection threshold scores significantly improved 4 weeks after treatment initiation compared to the pre-treatment threshold scores. The olfactory recovery rates in patients treated with VPA were clearly better than those we previously reported in PVOD patients who received Toki-shakuyaku-san, the traditional treatment in Japan. The olfactory recovery rates of patients with PVOD at 12 weeks and 24 weeks of VPA treatment were both 77.8%, and the olfactory cure rates at 12 weeks and 24 weeks of VPA treatment were 33.3% and 44.4%, respectively. No serious adverse events were observed. CONCLUSIONS VPA seems to be a safe treatment option in patients with PVOD. The effects of VPA treatment for PVOD patients should be studied with a controlled study design in the future.
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Affiliation(s)
- Takao Ogawa
- Department of Otorhinolaryngology, Shiga University of Medical Science, Shiga, Japan
| | - Koji Matsumoto
- Department of Otorhinolaryngology, Shiga University of Medical Science, Shiga, Japan
| | - Ichiro Tojima
- Department of Otorhinolaryngology, Shiga University of Medical Science, Shiga, Japan
| | - Hirotaka Kikuoka
- Department of Otorhinolaryngology, Shiga University of Medical Science, Shiga, Japan
| | - Daiki Hira
- Department of Pharmacy, Kyoto University Hospital, Kyoto, Japan
| | - Takeshi Shimizu
- Department of Otorhinolaryngology, Shiga University of Medical Science, Shiga, Japan
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Sousa FAD, Machado AS, da Costa JC, Silva AC, Pinto AN, Coutinho MB, Meireles L, Sousa CAE. Tailored Approach for Persistent Olfactory Dysfunction After SARS-CoV-2 Infection: A Pilot Study. Ann Otol Rhinol Laryngol 2022; 132:657-666. [PMID: 35822286 DOI: 10.1177/00034894221111093] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVE So far, no original studies explored non-randomized, standardized protocols for COVID-19 associated olfactory dysfunction. The main objective was to determine the efficacy of a new protocol for post-COVID olfactopathy while assessing the benefit of adding adjuvant therapies to olfactory training. METHODS Patients suffering from long-lasting post-COVID-19 olfactory dysfunction were evaluated. A non-randomized protocol based on individual nasal endoscopy findings and patient's preferences was applied. Patients were assigned for olfactory training alone or olfactory training + adjuvant therapy. Participants performed olfactory objective and subjective evaluations at first consultation and 3 months after treatment, and results were compared. RESULTS A total of 47 patients were enrolled. All groups showed significant improvement in olfactory thresholds at 3-month follow-up suggesting protocol effectiveness (olfactory training group alone showed a mean threshold difference of 2.9, P < .001; Olfactory training + Topical Corticosteroid showed a mean threshold difference of 4, P = .006; Olfactory training + Topical Corticosteroid + Vitamin B complex showed a mean threshold difference of 4.4, P = .006; Olfactory training + Intranasal Vitamin A and E showed a mean threshold difference of 4.4, P < .001). Olfactory training alone showed lower mean olfactory threshold improvement, when compared to patients undergoing olfactory training + adjuvant therapy (olfactory training alone mean improvement 2.9 ± 2.3 vs olfactory training + adjuvants mean improvement 4.3 ± 2.458, P = .03). CONCLUSIONS This is one of the first studies to demonstrate results in the treatment of post-COVID-19 persistent olfactory impairment. A customized approach based on endoscopy findings and patient's preferences may be a valid option for the management of persistent post-COVID-19 olfactory disorder. Adjuvant therapy could be considered in addition to olfactory training, but further studies are needed in order to confirm their effectiveness in this setting. LEVEL OF EVIDENCE 2c (outcomes research).
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Affiliation(s)
- Francisco Alves de Sousa
- Serviço de Otorrinolaringologia e Cirurgia da Cabeça e Pescoço (Otorhinolaryngology and Head & Neck Surgery), Centro Hospitalar Universitário do Porto, Porto, Portugal
| | - André Sousa Machado
- Serviço de Otorrinolaringologia e Cirurgia da Cabeça e Pescoço (Otorhinolaryngology and Head & Neck Surgery), Centro Hospitalar Universitário do Porto, Porto, Portugal
| | - Joana Carvalho da Costa
- Serviço de Otorrinolaringologia e Cirurgia da Cabeça e Pescoço (Otorhinolaryngology and Head & Neck Surgery), Centro Hospitalar Universitário do Porto, Porto, Portugal
| | - Ana Costa Silva
- Serviço de Otorrinolaringologia e Cirurgia da Cabeça e Pescoço (Otorhinolaryngology and Head & Neck Surgery), Centro Hospitalar Universitário do Porto, Porto, Portugal
| | - Ana Nóbrega Pinto
- Serviço de Otorrinolaringologia e Cirurgia da Cabeça e Pescoço (Otorhinolaryngology and Head & Neck Surgery), Centro Hospitalar Universitário do Porto, Porto, Portugal
| | - Miguel Bebiano Coutinho
- Serviço de Otorrinolaringologia e Cirurgia da Cabeça e Pescoço (Otorhinolaryngology and Head & Neck Surgery), Centro Hospitalar Universitário do Porto, Porto, Portugal
| | - Luís Meireles
- Serviço de Otorrinolaringologia e Cirurgia da Cabeça e Pescoço (Otorhinolaryngology and Head & Neck Surgery), Centro Hospitalar Universitário do Porto, Porto, Portugal
| | - Cecília Almeida E Sousa
- Serviço de Otorrinolaringologia e Cirurgia da Cabeça e Pescoço (Otorhinolaryngology and Head & Neck Surgery), Centro Hospitalar Universitário do Porto, Porto, Portugal
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Dal Bò E, Gentili C, Castellani A, Tripodi C, Fischmeister FPS, Cecchetto C. Olfactory meta-cognition in individuals with depressive and anxiety symptoms: The differential role of common and social odors. J Affect Disord 2022; 308:259-267. [PMID: 35429542 DOI: 10.1016/j.jad.2022.04.071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 02/21/2022] [Accepted: 04/10/2022] [Indexed: 10/18/2022]
Abstract
BACKGROUND Diminished olfactory functioning has been reported in depression, whereas evidence in anxiety disorders is still controversial. Olfactory meta-cognitive abilities (i.e., olfactory awareness, imagery and reactivity, and the importance of odors) are essential in shaping olfaction. Few studies examined these meta-cognitive abilities in relation to depressive, anxiety, and social anxiety symptoms, and none of them considered the awareness of social odors (i.e., body odors). METHODS This pre-registered study examined the relationship between olfactory meta-cognitive abilities and symptoms of depression, general anxiety, and social anxiety in 429 individuals. Self-report measures of symptoms of depression, general anxiety, and social anxiety, along with self-report olfactory meta-cognitive scales, were collected using an online survey. RESULTS Linear regression analyses revealed that olfactory awareness and importance of common odors were significantly directly predicted by symptoms of general anxiety, while affective importance to odors was negatively predicted by symptoms of depression. Regarding social odors, higher symptoms of depression and lower symptoms of social anxiety predicted increased awareness. LIMITATIONS Higher prevalence of women and narrow age range of the participants. Depressive and anxiety symptoms were assessed only with self-report questionnaires. CONCLUSIONS Symptoms of anxiety seem to be associated with higher levels of common odor awareness, corroborating the importance of olfactory functions in anxiety. In addition, results on social odors seem to reflect dysfunctional social behaviour that characterized symptoms of depression and social anxiety. Hence, the assessment of meta-cognitive abilities may represent a useful tool in the prevention and assessment of depressive, anxiety, and social anxiety symptoms.
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Affiliation(s)
- Elisa Dal Bò
- Padova Neuroscience Center (PNC), University of Padua, Via Orus 2/B, 35131 Padua, Italy; Department of General Psychology, University of Padua, Via Venezia 8, 35131 Padua, Italy
| | - Claudio Gentili
- Padova Neuroscience Center (PNC), University of Padua, Via Orus 2/B, 35131 Padua, Italy; Department of General Psychology, University of Padua, Via Venezia 8, 35131 Padua, Italy
| | - Andrea Castellani
- Department of General Psychology, University of Padua, Via Venezia 8, 35131 Padua, Italy
| | - Carmen Tripodi
- Department of General Psychology, University of Padua, Via Venezia 8, 35131 Padua, Italy
| | - Florian Ph S Fischmeister
- Institute of Psychology, University of Graz, Graz, Austria; BioTechMed, Graz, Austria; Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Cinzia Cecchetto
- Department of General Psychology, University of Padua, Via Venezia 8, 35131 Padua, Italy.
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Koyama S, Heinbockel T. Chemical Constituents of Essential Oils Used in Olfactory Training: Focus on COVID-19 Induced Olfactory Dysfunction. Front Pharmacol 2022; 13:835886. [PMID: 35721200 PMCID: PMC9201274 DOI: 10.3389/fphar.2022.835886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 04/12/2022] [Indexed: 11/13/2022] Open
Abstract
The recent increase in the number of patients with post-viral olfactory dysfunction (PVOD) following the outbreak of COVID-19 has raised the general interest in and concern about olfactory dysfunction. At present, no clear method of treatment for PVOD has been established. Currently the most well-known method to improve the symptoms of olfactory dysfunction is "olfactory training" using essential oils. The essential oils used in olfactory training typically include rose, lemon, clove, and eucalyptus, which were selected based on the odor prism hypothesis proposed by Hans Henning in 1916. He classified odors based on six primary categories or dimensions and suggested that any olfactory stimulus fits into his smell prism, a three-dimensional space. The term "olfactory training" has been used based on the concept of training olfactory sensory neurons to relearn and distinguish olfactory stimuli. However, other mechanisms might contribute to how olfactory training can improve the recovery of the olfactory sense. Possibly, the essential oils contain chemical constituents with bioactive properties that facilitate the recovery of the olfactory sense by suppressing inflammation and enhancing regeneration. In this review, we summarize the chemical constituents of the essential oils of rose, lemon, clove, and eucalyptus and raise the possibility that the chemical constituents with bioactive properties are involved in improving the symptoms of olfactory dysfunction. We also propose that other essential oils that contain chemical constituents with anti-inflammatory effects and have binding affinity with SARS-CoV-2 can be new candidates to test their efficiencies in facilitating the recovery.
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Affiliation(s)
- Sachiko Koyama
- Department of Chemistry, College of Arts and Sciences, Indiana University, Bloomington, IN, United States
| | - Thomas Heinbockel
- Department of Anatomy, College of Medicine, Howard University, Washington, DC, United States
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Olfactory and gustatory disorders in COVID-19. ALLERGO JOURNAL INTERNATIONAL 2022; 31:243-250. [PMID: 35755859 PMCID: PMC9208356 DOI: 10.1007/s40629-022-00216-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 04/28/2022] [Indexed: 12/05/2022]
Abstract
Loss of olfaction is one of the symptoms most commonly reported by patients with coronavirus disease 2019 (COVID-19). Although the spontaneous recovery rate is high, recent studies have shown that up to 7% of patients remain anosmic for more than 12 months after the onset of infection, leaving millions of people worldwide suffering from severe olfactory impairment. Olfactory training remains the first recommended treatment. With the continued lack of approved drug treatments, new therapeutic options are being explored. This article reviews the current state of science on COVID-19-related olfactory disorders, focusing on epidemiology, pathophysiology, cure rates, currently available treatment options, and research on new treatments.
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