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Vance DE, Del Bene VA, Kamath V, Frank JS, Billings R, Cho DY, Byun JY, Jacob A, Anderson JN, Visscher K, Triebel K, Martin KM, Li W, Puga F, Fazeli PL. Does Olfactory Training Improve Brain Function and Cognition? A Systematic Review. Neuropsychol Rev 2024; 34:155-191. [PMID: 36725781 PMCID: PMC9891899 DOI: 10.1007/s11065-022-09573-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Accepted: 12/01/2022] [Indexed: 02/03/2023]
Abstract
Olfactory training (OT), or smell training,consists of repeated exposure to odorants over time with the intended neuroplastic effect of improving or remediating olfactory functioning. Declines in olfaction parallel declines in cognition in various pathological conditions and aging. Research suggests a dynamic neural connection exists between olfaction and cognition. Thus, if OT can improve olfaction, could OT also improve cognition and support brain function? To answer this question, we conducted a systematic review of the literature to determine whether there is evidence that OT translates to improved cognition or altered brain morphology and connectivity that supports cognition. Across three databases (MEDLINE, Scopus, & Embase), 18 articles were identified in this systematic review. Overall, the reviewed studies provided emerging evidence that OT is associated with improved global cognition, and in particular, verbal fluency and verbal learning/memory. OT is also associated with increases in the volume/size of olfactory-related brain regions, including the olfactory bulb and hippocampus, and altered functional connectivity. Interestingly, these positive effects were not limited to patients with smell loss (i.e., hyposmia & anosmia) but normosmic (i.e., normal ability to smell) participants benefitted as well. Implications for practice and research are provided.
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Affiliation(s)
- David E Vance
- School of Nursing, University of Alabama at Birmingham, 1701 University Boulevard, Birmingham, AL, USA.
| | - Victor A Del Bene
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Vidyulata Kamath
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Jennifer Sandson Frank
- School of Nursing, University of Alabama at Birmingham, 1701 University Boulevard, Birmingham, AL, USA
| | - Rebecca Billings
- UAB Libraries, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Do-Yeon Cho
- Department of Surgery, Veterans Affairs, University of Alabama at Birmingham, & Division of Otolaryngology, Birmingham, AL, USA
| | - Jun Y Byun
- School of Nursing, University of Alabama at Birmingham, 1701 University Boulevard, Birmingham, AL, USA
| | - Alexandra Jacob
- Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Joseph N Anderson
- School of Medicine, Department of Neurology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Kristina Visscher
- Department of Neurobiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Kristen Triebel
- School of Medicine, Department of Neurology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Karli M Martin
- School of Medicine, Department of Neurology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Wei Li
- Department of Clinical and Diagnostic Sciences, School of Health Professions, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Frank Puga
- School of Nursing, University of Alabama at Birmingham, 1701 University Boulevard, Birmingham, AL, USA
| | - Pariya L Fazeli
- School of Nursing, University of Alabama at Birmingham, 1701 University Boulevard, Birmingham, AL, USA
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Heian IT, Thorstensen WM, Myklebust TA, Hummel T, Nordgard S, Bratt M, Helvik AS, Helvik AS. Olfactory training in normosmic individuals: a randomised controlled trial. Rhinology 2024; 62:46-54. [PMID: 37847818 DOI: 10.4193/rhin23.229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2023]
Abstract
BACKGROUND Even if olfactory training (OT) is a well-established treatment for individuals with olfactory dysfunction, the effect on individuals with normosmia remains uncertain. In this randomised controlled trial, we explore how OT with different exposure lengths affect olfactory function in individuals with normosmia. METHODOLOGY Two hundred normosmic individuals were randomly assigned to one of two intervention groups performing OT with different exposure lengths or to a control group. The OT groups did OT twice daily for three months, g four different odours (eucalyptus, lavender, mint, and lemon) for 10 seconds per bottle during either a total of 40 seconds (standard OT) or 4 minutes (extended OT), while the control group did not perform any OT. Olfactory function was assessed using a 48-item Sniffin Sticks test at baseline, after the intervention, and after one year. RESULTS We found no significant effect of OT in either of the intervention groups on any aspect of olfaction after intervention or at follow-up. There was no association between sex, age, allergic rhinitis, education or olfactory scores at baseline, and changes in olfactory function after OT. The extended OT group performed significantly fewer training sessions compared to those in the standard OT group. CONCLUSIONS OT had a limited effect on olfactory function in individuals with normosmia. Further, the superiority of a more extended OT is not supported by this study, and shorter training sessions seem to improve compliance with OT.
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Affiliation(s)
- I T Heian
- Institute of Neuromedicine and Movement Science (INB), Norwegian University of Science and Technology (NTNU), Trondheim, Norway; Department of Otolaryngology, Head and Neck Surgery, Molde Sjukehus, Helse More Romsdal, Molde, Norway; Department of Research and Innovation, Helse More and Romsdal, Norway
| | - W M Thorstensen
- Institute of Neuromedicine and Movement Science (INB), Norwegian University of Science and Technology (NTNU), Trondheim, Norway; Department of Otolaryngology, Head and Neck Surgery, St. Olavs University Hospital, Trondheim, Norway
| | - T A Myklebust
- Department of Research and Innovation, Helse More and Romsdal, Norway
| | - T Hummel
- Smell and Taste Clinic, Department of Otolaryngology, Universitatsklinikum, Technische Universitat Dresden, Germany
| | - S Nordgard
- Institute of Neuromedicine and Movement Science (INB), Norwegian University of Science and Technology (NTNU), Trondheim, Norway; Department of Otolaryngology, Head and Neck Surgery, St. Olavs University Hospital, Trondheim, Norway
| | - M Bratt
- Institute of Neuromedicine and Movement Science (INB), Norwegian University of Science and Technology (NTNU), Trondheim, Norway; Department of Otolaryngology, Head and Neck Surgery, St. Olavs University Hospital, Trondheim, Norway
| | - A S Helvik
- Department of Public Health and Nursing, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology (NTNU), Trondheim, Norway 7 Norwegian National Advisory Unit on Ageing and Health, Vestfold Health Trust, Tonsberg, Norway
| | - A S Helvik
- Department of Public Health and Nursing, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; Norwegian National Advisory Unit on Ageing and Health, Vestfold Health Trust, Tonsberg, Norway
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Haas M, Raninger J, Kaiser J, Mueller CA, Liu DT. Treatment adherence to olfactory training: a real-world observational study. Rhinology 2024; 62:35-45. [PMID: 37838940 DOI: 10.4193/rhin23.207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2023]
Abstract
BACKGROUND Olfactory training (OT) is considered an effective intervention for most causes of smell loss and is recommended as a long-term treatment. However, the treatment adherence of OT remains unclear. This study aims to identify the frequency and causalities for lack of adherence to OT. METHODS In this prospective study, 53 patients previously diagnosed with olfactory dysfunction (OD), who were recommended to perform OT, were enrolled. Patients underwent olfactory testing using Sniffin' Sticks for threshold, discrimination, and identification (TDI) and a subjective numeric rating scale (NRS) at a baseline and follow-up visit. In addition, patients answered a six-item treatment adherence questionnaire. The primary outcome measures were clinically relevant improvements according to the TDI (>=5.5) and NRS (>=5.5) scores. RESULTS Out of 53 patients, 45 performed OT. Among patients who performed OT, 31% discontinued the use of OT on their own due to a self-perceived improvement, while 51% discontinued use due to lack of improvements in olfaction. In these patients, the average duration of OT use was five months. After controlling for baseline duration of OD, baseline TDI score and smell loss aetiologies, discontinuing OT due to a lack of self-perceived improvement remained significantly associated with worse TDI and NRS outcomes at follow-up. CONCLUSIONS Our data show that therapeutical adherence to OT is low, regardless of patients' perception of olfactory function. Olfactory improvement leads to decreased training due to satisfaction, while lack of improvement leads to non-adherence based on disappointing subjective outcome. Patients should be advised to perform OT consistently.
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Affiliation(s)
- M Haas
- Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna, Austria
| | - J Raninger
- Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna, Austria
| | - J Kaiser
- Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna, Austria
| | - C A Mueller
- Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna, Austria
| | - D T Liu
- Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna, Austria
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Pieniak M, Hummel T. Do people stop conducting olfactory training when their olfaction recovers? Rhinology 2024; 62:127-128. [PMID: 37516987 DOI: 10.4193/rhin23.140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/01/2023]
Affiliation(s)
- M Pieniak
- Smell and Taste Clinic, Department of Otorhinolaryngology, Faculty of Medicine Carl Gustav Carus, Technische Universitat Dresden, Dresden, Germany and Institute of Psychology, University of Wroclaw, Wroclaw, Poland
| | - T Hummel
- Smell and Taste Clinic, Department of Otorhinolaryngology, Faculty of Medicine Carl Gustav Carus, Technische Universitat Dresden, Dresden, Germany
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Genetzaki S, Nikolaidis V, Markou K, Konstantinidis I. Olfactory training with four and eight odors: comparison with clinical testing and olfactory bulb volumetrics. Eur Arch Otorhinolaryngol 2024; 281:497-502. [PMID: 37924364 PMCID: PMC10764551 DOI: 10.1007/s00405-023-08283-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 10/09/2023] [Indexed: 11/06/2023]
Abstract
PURPOSE Post-infectious olfactory dysfunction (PIOD) is one of the most common causes of olfactory impairment but has limited treatment options. Recently, olfactory training (OT) has been considered an effective treatment method; however, several questions have arisen regarding its optimal scheme. The aim of this study was to assess whether an OT scheme with 8 odors is more effective than the classic OT scheme with 4 odors by comparing psychophysical test results and olfactory bulb (OB) volumetrics. METHODS In this prospective cohort study, 72 patients with PIOD were included. The patients followed either the classic 4-odor OT scheme (COT; n = 34 patients) or an extended 8-odor scheme (EOT; n = 38 patients) for 16 weeks. All patients underwent olfactory testing with a Sniffin'Sticks battery test at 0, 8, and 16 weeks. Of the patients, 38 underwent brain magnetic resonance imaging for OB volumetric assessment before and after treatment. RESULTS The comparison of the olfactory test results did not show any significant difference between the two study groups, in agreement with the OB volumetrics. The convex OB showed better test results than the non-convex OB, with significantly better improvement after treatment regardless of OT type. The EOT group presented significantly better adherence than the COT group. CONCLUSION The number of odors did not appear to play a significant role in the effect of the OT. However, the training scheme with more than four odors showed better adherence among the patients in a long-term treatment plan. The shape of the OB may have prognostic value in clinical assessment and warrants further investigation.
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Affiliation(s)
- Sotiria Genetzaki
- 2nd ORL Academic Department, Aristotle University, Thessaloniki, Greece
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Chan KH, Thomas BJ, Gilbert DD, Tong S, Teynor NJ, Friedman NR, Herrmann BW, Gitomer SA. Olfactory dysfunction and training in children with COVID-19 infection: A prospective study Post-COVID pediatric olfactory training. Int J Pediatr Otorhinolaryngol 2024; 176:111799. [PMID: 38081110 DOI: 10.1016/j.ijporl.2023.111799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 11/06/2023] [Accepted: 11/19/2023] [Indexed: 01/08/2024]
Abstract
OBJECTIVE Postviral olfactory dysfunction (OD) including corona 2019 viral disease (COVID-19) OD occurs in both adults and children. Despite limited reports of efficacy in treating adult postviral including COVID-19 OD with olfactory training (OT), its effects on children in general, and post-COVID-19 in specific, is unknown. The study aimed at evaluating the effects of OT in a COVID-19 OD pediatric cohort. METHODS A single-arm prospective study of pediatric COVID-19 OD subjects confirmed by the University of Pennsylvania Smell Identification Test (UPSIT), was conducted. All subjects underwent OT by sniffing 4 odorants (lavender, orange, peppermint, and eucalyptus) for 1 min twice a day for 3 months. Subjects underwent an odorant identification test (OIT) of the 4 odorants each visit. A repeat UPSIT was administered at the 4th visit. RESULTS The study enrolled a total of 37 subjects [11 males/26 females with mean age/standard deviation (std) of 15.6(2.1) years]. The time interval between COVID-19 and entry was 5.3(2.4) months. The mean pre/post study UPSIT score improvement was 2.3(4.7), p = .09. OIT scores between entry and 3 subsequent visits showed a mean improvement of 1.8(1.5), 1.8(1.9) and 2.3(1.9) odorants, respectively, with P < .001 for all 3 comparisons. CONCLUSIONS OT subjects were predominantly female teens with substantial OD lasting greater than 5 months. OT did not affect OD as measured by UPSIT but OIT scores improved during OT. We postulate that OT likely has a role in pediatric post-COVID OD recovery, but UPSIT likely is too rigid to detect disparate odorant improvement.
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Affiliation(s)
- Kenny H Chan
- Department of Otolaryngology, University of Colorado School of Medicine, Children's Hospital Colorado, Aurora, CO, USA; Department of Otolaryngology, Children's Hospital Colorado, Aurora, CO, USA.
| | - Bethany J Thomas
- Department of Otolaryngology, University of Colorado School of Medicine, Children's Hospital Colorado, Aurora, CO, USA; Department of Otolaryngology, Children's Hospital Colorado, Aurora, CO, USA
| | - Deborah D Gilbert
- Department of Otolaryngology, University of Colorado School of Medicine, Children's Hospital Colorado, Aurora, CO, USA; Department of Otolaryngology, Children's Hospital Colorado, Aurora, CO, USA
| | - Suhong Tong
- Department of Pediatrics, School of Medicine and Department of Biostatistics and Informatics, School of Public Health, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Nathan J Teynor
- Department of Otolaryngology, Children's Hospital Colorado, Aurora, CO, USA
| | - Norman R Friedman
- Department of Otolaryngology, University of Colorado School of Medicine, Children's Hospital Colorado, Aurora, CO, USA; Department of Otolaryngology, Children's Hospital Colorado, Aurora, CO, USA
| | - Brian W Herrmann
- Department of Otolaryngology, University of Colorado School of Medicine, Children's Hospital Colorado, Aurora, CO, USA; Department of Otolaryngology, Children's Hospital Colorado, Aurora, CO, USA
| | - Sarah A Gitomer
- Department of Otolaryngology, University of Colorado School of Medicine, Children's Hospital Colorado, Aurora, CO, USA; Department of Otolaryngology, Children's Hospital Colorado, Aurora, CO, USA
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Figueiredo LP, Paim PVDSL, Cerqueira-Silva T, Barreto CC, Lessa MM. Alpha-lipoic acid does not improve olfactory training results in olfactory loss due to COVID-19: a double-blind randomized trial. Braz J Otorhinolaryngol 2024; 90:101356. [PMID: 37944311 PMCID: PMC10665681 DOI: 10.1016/j.bjorl.2023.101356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 10/05/2023] [Accepted: 10/16/2023] [Indexed: 11/12/2023] Open
Abstract
OBJECTIVES Olfactory loss is a recognized long-term dysfunction after Coronavirus Disease 2019 (COVID-19) infection. This investigation aimed to assess the effect of alpha-lipoic acid as an adjuvant treatment of olfactory training on the improvement of smell loss in post-COVID-19 patients. METHODS This randomized controlled trial included 128 adult outpatients who had persistent smell loss for more than 3-months after COVID-19 infection. The participants were randomly allocated into two groups: the intervention treatment group, which received alpha-lipoic acid associated to olfactory training, and comparison treatment group, which received placebo pills associated to olfactory training. The participants were followed-up for 12-weeks. Olfactory dysfunction was assessed in terms of Visual Analog Scale (VAS), and the Connecticut Chemosensory Clinical Research Center (CCCRC) test for the Brazilian population. RESULTS A total of 100 participants completed the follow-up period and were analyzed in this study. Both groups have improved CCCRC score (p = 0.000), olfactory threshold (p = 0.000), identification score (p = 0.000) and VAS score (p = 0.000) after 12-weeks follow-up. No significant differences were determined between the intervention and comparison treatment groups in CCCRC score (p = 0.63), olfactory threshold (p = 0.50), identification score (p = 0.96) and VAS score (p = 0.97). In all these criteria, comparison treatment group went slightly worse. At the endpoint of the study, the frequency of anosmia reduced to 2% in the intervention treatment group and to 7.8% in the comparison treatment group. Also, 16.8% of the intervention group' subjects, and 15.7% of comparison treatment group's patients reached normosmia. CONCLUSIONS Overall, there was a strongly significant difference in olfactory function between baseline and endpoint for both groups. However, based on the lack of significant difference between the intervention treatment and the comparison treatment groups in terms of olfactory changes, our study appoints that the alpha-lipoic acid is not better than olfactory training alone to treat olfactory loss after COVID-19. LEVEL OF EVIDENCE Level 2.
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Affiliation(s)
- Lorena Pinheiro Figueiredo
- Universidade Federal da Bahia (UFBA), Programa de Pós-Graduação em Ciências da Saúde, Salvador, BA, Brazil.
| | | | | | - Carolina Cincurá Barreto
- Universidade Federal da Bahia (UFBA), Hospital Universitário Professor Edgard Santos (HUPES), Serviço de Otorrinolaringologia, Salvador, BA, Brazil
| | - Marcus Miranda Lessa
- Universidade Federal da Bahia (UFBA), Hospital Universitário Professor Edgard Santos (HUPES), Serviço de Otorrinolaringologia, Salvador, BA, Brazil
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Di Stadio A, Gallina S, Cocuzza S, De Luca P, Ingrassia A, Oliva S, Sireci F, Camaioni A, Ferreli F, Mercante G, Gaino F, Pace GM, La Mantia I, Brenner MJ. Treatment of COVID-19 olfactory dysfunction with olfactory training, palmitoylethanolamide with luteolin, or combined therapy: a blinded controlled multicenter randomized trial. Eur Arch Otorhinolaryngol 2023; 280:4949-4961. [PMID: 37380908 PMCID: PMC10562315 DOI: 10.1007/s00405-023-08085-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Accepted: 06/17/2023] [Indexed: 06/30/2023]
Abstract
PURPOSE Few evidence-based therapies are available for chronic olfactory dysfunction after COVID-19. This study investigated the relative efficacy of olfactory training alone, co-ultramicronized palmitoylethanolamide with luteolin (um-PEA-LUT, an anti-neuroinflammatory supplement) alone, or combined therapy for treating chronic olfactory dysfunction from COVID-19. METHODS This double-blinded controlled, placebo-controlled multicenter randomized clinical trial was conducted in 202 patients with persistent COVID-19 olfactory dysfunction of > 6 month duration. After a screening nasal endoscopy, patients were randomized to: (1) olfactory training and placebo; (2) once daily um-PEA-LUT alone; (3) twice daily um-PEA-LUT alone; or (4) combination of once daily um-PEA-LUT with olfactory training. Olfactory testing (Sniffin' Sticks odor identification test) was performed at baseline and at 1, 2, and 3 months. The primary outcome was recovery of over three points on olfactory testing, with outcomes compared at T0, T1, T2 and T3 across groups. Statistical analyses included one-way ANOVA for numeric data and chi-square for nominal data. RESULTS All patients completed the study, and there were no adverse events. At 90 days, odor identification scores improved by > 3 points in 89.2% of patients receiving combined therapy vs. 36.8% receiving olfactory training with placebo, 40% receiving twice daily um-PEA-LUT alone, and 41.6% receiving once daily um-PEA-LUT alone (p < 0.00001). Patients receiving treatment with um-PEA-LUT alone demonstrated subclinical improvement (< 3 point odor identification improvement) more often than patients receiving olfactory training with placebo (p < 0.0001.) CONCLUSIONS: Olfactory training plus once daily um-PEA-LUT resulted in greater olfactory recovery than either therapy alone in patients with long-term olfactory function due to COVID-19. TRIAL REGISTRATION 20112020PGFN on clinicaltrials.gov. LEVEL OF EVIDENCE 1b (Individual Randomized Clinical Trial).
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Affiliation(s)
- Arianna Di Stadio
- Otolaryngology Unit, GF Ingrassia Department, University of Catania, Catania, Italy.
| | | | - Salvatore Cocuzza
- Otolaryngology Unit, GF Ingrassia Department, University of Catania, Catania, Italy
| | - Pietro De Luca
- Otolaryngology Department, San Giovanni-Addolorata Hospital, Rome, Italy
| | - Angelo Ingrassia
- Otolaryngology Department, University of Palermo, Palermo, Italy
| | - Simone Oliva
- Otolaryngology Department, University of Palermo, Palermo, Italy
| | - Federico Sireci
- Otolaryngology Department, University of Palermo, Palermo, Italy
| | - Angelo Camaioni
- Otolaryngology Department, San Giovanni-Addolorata Hospital, Rome, Italy
| | - Fabio Ferreli
- Otolaryngology Department, Humanitas University Hospital, Milan, Italy
| | - Giuseppe Mercante
- Otolaryngology Department, Humanitas University Hospital, Milan, Italy
| | - Francesca Gaino
- Otolaryngology Department, Humanitas University Hospital, Milan, Italy
| | - Gian Marco Pace
- Otolaryngology Department, Humanitas University Hospital, Milan, Italy
| | - Ignazio La Mantia
- Otolaryngology Unit, GF Ingrassia Department, University of Catania, Catania, Italy
| | - Michael J Brenner
- Department of Otolaryngology-Head and Neck Surgery, University of Michigan Medical School, Ann Arbor, MI, USA
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Bogdanov V, Posala M, Herzog M. Olfactory rehabilitation via retronasal olfaction using a tracheoesophageal voice prosthesis after total laryngectomy. HNO 2023; 71:19-25. [PMID: 36480048 DOI: 10.1007/s00106-022-01229-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/30/2022] [Indexed: 12/13/2022]
Affiliation(s)
- V Bogdanov
- Department of Otorhinolaryngology, Head and Neck Surgery, Carl-Thiem-Klinikum Cottbus gGmbH, Thiemstr. 111, 03048, Cottbus, Germany.
- Smell & Taste Clinic, Department of Otorhinolaryngology, "Technische Universität Dresden", Dresden, Germany.
| | - M Posala
- Department of Otorhinolaryngology, Head and Neck Surgery, Carl-Thiem-Klinikum Cottbus gGmbH, Thiemstr. 111, 03048, Cottbus, Germany
| | - M Herzog
- Department of Otorhinolaryngology, Head and Neck Surgery, Carl-Thiem-Klinikum Cottbus gGmbH, Thiemstr. 111, 03048, Cottbus, Germany
- Department of Otorhinolaryngology, Head and Neck Surgery, Martin-Luther-University, Halle - Wittenberg, Halle (Saale), Germany
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Faria V, Dulheuer J, Joshi A, Wahl H, Klimova A, Haehner A, Gossrau G. Impact of a 12-week olfactory training programme in women with migraine with aura: protocol for a double-blind, randomised, placebo-controlled trial. BMJ Open 2023; 13:e071443. [PMID: 37419649 PMCID: PMC10335595 DOI: 10.1136/bmjopen-2022-071443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 06/04/2023] [Indexed: 07/09/2023] Open
Abstract
INTRODUCTION Migraine is a leading cause of disability and suffering worldwide. However, conventional pharmacological migraine preventive therapies are often challenging and accompanied by adverse effects. Recently, structured odour exposure has shown to successfully increase pain thresholds in patients with chronic back pain. Despite the importance of the olfactory system in migraine, there are no studies investigating the impact of structured odour exposure in patients with migraine. METHODS AND ANALYSIS This double-blind randomised placebo-controlled trial will be conducted at the Headache Clinic of the University Pain Center at TU Dresden, Germany and aims at investigating the impact of a 12-week structured exposure to odours in women with migraine. Fifty-four women between 18 and 55 years with migraine with aura will be recruited and randomised to training with odours and odourless training. The primary outcomes are mechanical and electrical pain thresholds. Secondary outcomes comprise olfactory threshold and the number of headache days. Other exploratory measurements are headache associated pain intensity, acute analgesic intake, symptoms of anxiety and depression, and quality of life. Additionally, this protocol assesses neuroanatomical and neurofunctional changes associated with the 12-week olfactory training. Data analysis will be executed on the basis of the general linear model considering repeated measurements. ETHICS AND DISSEMINATION Ethical approvals were obtained from the Ethics Board of the TU Dresden (Protocol No. BO-EK-353082020). Participation will only be possible after written informed consent is provided. Findings will be disseminated through peer-reviewed journals and scientific conferences. TRIAL REGISTRATION NUMBER DRKS00027399.
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Affiliation(s)
- Vanda Faria
- Department of Otorhinolaryngology, TU Dresden Faculty of Medicine Carl Gustav Carus, Dresden, Germany
- Department of Psychology, Uppsala University, Uppsala, Sweden
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Jana Dulheuer
- Department of Otorhinolaryngology, TU Dresden Faculty of Medicine Carl Gustav Carus, Dresden, Germany
| | - Akshita Joshi
- Department of Otorhinolaryngology, TU Dresden Faculty of Medicine Carl Gustav Carus, Dresden, Germany
| | - Hannes Wahl
- Intitute of Neuroradiology, TU Dresden Faculty of Medicine Carl Gustav Carus, Dresden, Germany
| | - Anna Klimova
- NCT Partner Site Dresden, Institute for Medical Informatics and Biometrics, TU Dresden Faculty of Medicine Carl Gustav Carus, Dresden, Germany
| | - Antje Haehner
- Department of Otorhinolaryngology, TU Dresden Faculty of Medicine Carl Gustav Carus, Dresden, Germany
| | - Gudrun Gossrau
- Interdisciplinary Pain Center, University Hospital, and Faculty of Medicine Carl Gustav Carus, TU Dresden, Dresden, Germany
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Khan AM, Kallogjeri D, Piccirillo JF. Visual- Olfactory Training and Patient Preference in Treatment of COVID-19 Olfactory Loss-How Salient Stimuli Might Support Recovery of Smell-Reply. JAMA Otolaryngol Head Neck Surg 2023; 149:651. [PMID: 37261823 DOI: 10.1001/jamaoto.2023.1135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
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
| | - 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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Di Stadio A, D'Ascanio L, Brenner MJ. Visual- Olfactory Training and Patient Preference in Treatment of COVID-19 Olfactory Loss-How Salient Stimuli Might Support Recovery of Smell. JAMA Otolaryngol Head Neck Surg 2023; 149:650. [PMID: 37261815 DOI: 10.1001/jamaoto.2023.1134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Affiliation(s)
- Arianna Di Stadio
- Department GF Ingrassia, University of Catania, Catania, Italy
- Santa Lucia Hospital (IRCSS), Rome, Italy
| | - Luca D'Ascanio
- Department Otorhinolaryngology, Azienda Ospeliera Riunita Marche Nord (AORMN), Fano, Pesaro-Urbino, Italy
| | - Michael J Brenner
- Department of Otolaryngology-Head and Neck Surgery, University of Michigan, Ann Arbor
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14
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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15
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Li Z, Anne A, Hummel T. Olfactory training: effects of multisensory integration, attention towards odors and physical activity. Chem Senses 2023; 48:bjad037. [PMID: 37715960 DOI: 10.1093/chemse/bjad037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Indexed: 09/18/2023] Open
Abstract
Olfactory training (OT) has been shown to be of value in the treatment of olfactory dysfunction. The present study aimed to investigate whether the efficacy of OT could be modulated with multisensory integration, attention towards odors, odor complexity, or physical activity assessed with a questionnaire. One hundred healthy participants were recruited and divided into 4 groups. Except for controls (n = 26, mean age ± SD = 36 ± 15 years) all participants performed OT 4 times a day. In the "video" group (n = 26, age 39 ± 19 years) OT was performed while watching specific and congruent video sequences. In the "counter" group (n = 24, 38 ± 17 years) participants additionally counted the number of odors 1 day per week, and in the "training only" group no additional measures were taken in addition to OT (n = 24, 38 ± 20 years). "Single-molecule" odorants or "complex mixtures" were distributed randomly for training stimulation. Sniffin' sticks tests (odor identification, odor discrimination, and odor threshold), cognitive tests, and a series of scales were measured at both baseline and after 3 months of OT. The degree of physical activity was recorded with a questionnaire. Olfactory function improved in the video and counter groups after OT, especially for odor threshold and discrimination. Yet, odor complexity and the degree of physical activity had limited effects on olfactory improvement after OT. Both multisensory interaction and attention towards odors plus OT appeared to facilitate improvement of olfactory function in healthy individuals compared with OT alone and controls, which could provide new promising treatments for clinical applications.
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Affiliation(s)
- Zetian Li
- Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Fetscherstarsse 74, 01307 Dresden, Germany
| | - Abriat Anne
- The Smell and Taste Lab, Rue Cramer 6, 1202 Genève, Switzerland
| | - Thomas Hummel
- Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Fetscherstarsse 74, 01307 Dresden, Germany
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Peng H, Yang C, Jian F, Wu S. Study on a Flexible Odor-Releasing Device for Olfactory Training. Sensors (Basel) 2022; 22:9519. [PMID: 36502219 PMCID: PMC9741058 DOI: 10.3390/s22239519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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17
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Lechner M, Liu J, Counsell N, Gillespie D, Chandrasekharan D, Ta NH, Jumani K, Gupta R, Rao-Merugumala S, Rocke J, Williams C, Tetteh A, Amnolsingh R, Khwaja S, Batterham RL, Yan CH, Treibel TA, Moon JC, Woods J, Brunton R, Boardman J, Paun S, Eynon-Lewis N, Kumar BN, Jayaraj S, Hopkins C, Philpott C, Lund VJ. The COVANOS trial - insight into post-COVID olfactory dysfunction and the role of smell training. Rhinology 2022; 60:188-199. [PMID: 35901492 DOI: 10.4193/rhin21.470] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Olfactory dysfunction is a cardinal symptom of COVID-19 infection, however, studies assessing long-term olfactory dysfunction are limited and no randomised-controlled trials (RCTs) of early olfactory training have been conducted. METHODOLOGY We conducted a prospective, multi-centre study consisting of baseline psychophysical measurements of smell and taste function. Eligible participants were further recruited into a 12-week RCT of olfactory training versus control (safety information). Patient-reported outcomes were measured using an electronic survey and BSIT at baseline and 12 weeks. An additional 1-year follow-up was open to all participants. RESULTS 218 individuals with a sudden loss of sense of smell of at least 4-weeks were recruited. Psychophysical smell loss was observed in only 32.1%; 63 participants were recruited into the RCT. The absolute difference in BSIT improvement after 12 weeks was 0.45 higher in the intervention arm. 76 participants completed 1-year follow-up; 10/19 (52.6%) of participants with an abnormal baseline BSIT test scored below the normal threshold at 1-year, and 24/29 (82.8%) had persistent parosmia. CONCLUSIONS Early olfactory training may be helpful, although our findings are inconclusive. Notably, a number of individuals who completed the 1-year assessment had persistent smell loss and parosmia at 1-year. As such, both should be considered important entities of long-Covid and further studies to improve management are highly warranted.
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Affiliation(s)
- M Lechner
- ENT Department, Barts Health NHS Trust, London, UK; UCL Cancer Institute, University College London, London, UK; Division of Surgery and Interventional Science, University College London, London, UK
| | - J Liu
- UCL Cancer Institute, University College London, London, UK
| | - N Counsell
- CRUK and UCL Cancer Trials Centre, University College London, London, UK
| | - D Gillespie
- UCL Cancer Institute, University College London, London, UK
| | | | - N H Ta
- Norwich Medical School, University of East Anglia, Norwich, UK
| | - K Jumani
- ENT Department, Barts Health NHS Trust, London, UK
| | - R Gupta
- ENT Department, Barts Health NHS Trust, London, UK
| | | | - J Rocke
- ENT Department, Wrightington, Wigan and Leigh NHS Foundation Trust, Wigan, UK
| | - C Williams
- ENT Department, Wrightington, Wigan and Leigh NHS Foundation Trust, Wigan, UK
| | - A Tetteh
- ENT Department, Guy's Hospital, Guy's and St. Thomas' NHS Foundation Trust, London, UK
| | - R Amnolsingh
- Department of Otolaryngology, Manchester University NHS Foundation Trust, Manchester, UK
| | - S Khwaja
- Department of Otolaryngology, Manchester University NHS Foundation Trust, Manchester, UK
| | - R L Batterham
- Centre for Obesity Research, University College London, London, UK; Bariatric Centre for Weight Management and Metabolic Surgery, University College London Hospitals NHS Foundation Trust, London, UK; National Institute for Health Research, UCLH Biomedical Research Centre, London, UK
| | - C H Yan
- Department of Otolaryngology-Head and Neck Surgery, University of San Diego School of Medicine, San Diego, USA
| | - T A Treibel
- National Institute for Health Research, UCLH Biomedical Research Centre, London, UK; Barts Heart Centre, St. Bartholomew's Hospital, London, UK; Institute of Cardiovascular Sciences, University College London, UK
| | - J C Moon
- National Institute for Health Research, UCLH Biomedical Research Centre, London, UK; Barts Heart Centre, St. Bartholomew's Hospital, London, UK; Institute of Cardiovascular Sciences, University College London, UK
| | - J Woods
- The Norfolk Smell and Taste Clinic, Norfolk
| | - R Brunton
- ENT Department, Guy's Hospital, Guy's and St. Thomas' NHS Foundation Trust, London, UK
| | | | - S Paun
- ENT Department, Barts Health NHS Trust, London, UK
| | | | - B N Kumar
- ENT Department, Wrightington, Wigan and Leigh NHS Foundation Trust, Wigan, UK
| | - S Jayaraj
- ENT Department, Barts Health NHS Trust, London, UK
| | - C Hopkins
- ENT Department, Guy's Hospital, Guy's and St. Thomas' NHS Foundation Trust, London, UK
| | - C Philpott
- Norwich Medical School, University of East Anglia, Norwich, UK; The Norfolk Smell and Taste Clinic, Norfolk and Waveney ENT Service, UK
| | - V J Lund
- Royal National ENT Hospital, University College London Hospital NHS Foundation Trust, London, UK
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