Clinical Research in Olfactory and Gustatory Disorders: State of the Art

A special issue of Journal of Clinical Medicine (ISSN 2077-0383). This special issue belongs to the section "Clinical Neurology".

Deadline for manuscript submissions: 29 February 2024 | Viewed by 4102

Special Issue Editor

Institut für Klinische Pharmakologie, Technische Universität Dresden, 01307 Dresden, Germany
Interests: anosmia; hyposmia; parosmia

Special Issue Information

Dear Colleagues,

The loss of olfaction or gustation impacts a variety of daily tasks (e.g., the enjoyment of food and the ability to notice potential risks, such as toxins, gas or the smell of burning). The sources of impaired function are complex and include conductive (sinusitis), post-traumatic and post-infectious (viral, e.g., sensorineural) reasons, or they can be related to concomitant medications. There are also several neurodegenerative disorders, such as Parkinson’s disease and multiple sclerosis, which are accompanied by reduced olfactory function. In the last two to three decades, a variety of psychophysical tests, electrophysiological measures such as electroencephalography (EEG) or electro-olfactogram (EOG), as well as imaging techniques (functional magnetic resonance imaging—fMRI; magnetoencephalography—MEG) have been established to gain more insight into the diverse etiologies of impaired senses.

Based on the well-established Sniffin’ Sticks test battery, some new psychophysical test procedures (such as the SSParoT or the SSomix) have shown that not only quantitative (hyposmia and anosmia) but also qualitative (parosmia, anhedonia) olfactory dysfunction can be recorded and quantified in relation to normosmics. There are also new strategies for retronasal olfactory testing, which enable them to be sent by post during the COVID-19 pandemic. Clinical studies in health and disease using these validated test systems, as well as new procedures, are the scope of this Issue.

For this Special Issue, we invite authors to submit original works and state-of-the-art reviews on key aspects of clinical research in olfactory and gustatory disorders, with a focus on new and well-established (validated) psychophysical, electrophysiological and imaging techniques.

I look forward to and welcome your participation in this Special Issue.

Dr. Bertold Renner
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Journal of Clinical Medicine is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Olfaction
  • Gustation
  • Clinical trial
  • Anosmia
  • Hyposmia
  • Parosmia
  • fMRI
  • MEG
  • EEG
  • EOG

Published Papers (3 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Jump to: Other

12 pages, 288 KiB  
Article
Olfactory Dysfunction following COVID-19 and the Potential Benefits of Olfactory Training
J. Clin. Med. 2023, 12(14), 4761; https://doi.org/10.3390/jcm12144761 - 18 Jul 2023
Cited by 1 | Viewed by 1129
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 [...] Read more.
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. Full article
14 pages, 625 KiB  
Article
Olfactory and Gustatory Outcomes Including Health-Related Quality of Life 3–6 and 12 Months after Severe-to-Critical COVID-19: A SECURe Prospective Cohort Study
J. Clin. Med. 2022, 11(20), 6025; https://doi.org/10.3390/jcm11206025 - 12 Oct 2022
Cited by 2 | Viewed by 1243
Abstract
Background: Long-term follow-up studies of COVID-19 olfactory and gustatory disorders (OGDs) are scarce. OGD, parosmia, and dysgeusia affect health-related quality of life (HRQoL) and the ability to detect potential hazards. Methods: In this study, 29 patients reporting OGD 1 month after severe-to-critical COVID-19 [...] Read more.
Background: Long-term follow-up studies of COVID-19 olfactory and gustatory disorders (OGDs) are scarce. OGD, parosmia, and dysgeusia affect health-related quality of life (HRQoL) and the ability to detect potential hazards. Methods: In this study, 29 patients reporting OGD 1 month after severe-to-critical COVID-19 were tested at 3–6 months and retested at 12 months in case of hyposmia/anosmia. We used Sniffin Sticks Threshold, Discrimination, and Identification (TDI) test, Sniffin Sticks Identification Test (SIT16), Brief Smell Identification Test (BSIT), taste strips, and HRQoL. The patients were part of the prospective SECURe cohort. Results: Overall, 28% OD (TDI), 12% GD, 24% parosmia, and 24% dysgeusia (questionnaire) at 3–6 months (n = 29) and 28% OD (TDI), 38% parosmia, and 25% dysgeusia (questionnaire) at 12 months (n = 8) were observed. OGD decreased HRQoL: For 13%, it had a negative effect on daily life and, for 17%, it affected nutrition, 17% reported decreased mood, and 87–90% felt unable to navigate everyday life using their sense of smell and taste. A comparison of SIT16 and BSIT to TDI found sensitivity/specificity values of 75%/100% and 88%/86%. Conclusions: This is the first study to examine TDI, SIT16, BSIT, taste strips, and HRQoL up to 1 year after severe-to-critical COVID-19. The patients suffering from prolonged OGD, parosmia, and dysgeusia experienced severely decreasing HRQoL. We recommend including ear–nose–throat specialists in multidisciplinary post-COVID clinics. Full article
Show Figures

Figure 1

Other

Jump to: Research

9 pages, 995 KiB  
Brief Report
Olfaction and Anxiety Are Differently Associated in Men and Women in Cognitive Physiological and Pathological Aging
J. Clin. Med. 2023, 12(6), 2338; https://doi.org/10.3390/jcm12062338 - 17 Mar 2023
Viewed by 1132
Abstract
Background: Olfaction impairment in aging is associated with increased anxiety. We explored this association in cognitively healthy controls (HCs), Mild Cognitive Impairment (MCI) and Parkinson’s disease (PD) patients. Both olfaction and anxiety have sex differences, therefore we also investigated these variances. Objectives: Investigate [...] Read more.
Background: Olfaction impairment in aging is associated with increased anxiety. We explored this association in cognitively healthy controls (HCs), Mild Cognitive Impairment (MCI) and Parkinson’s disease (PD) patients. Both olfaction and anxiety have sex differences, therefore we also investigated these variances. Objectives: Investigate the association of olfaction with anxiety in three distinct clinical categories of aging, exploring the potential role of sex. Methods: 117 subjects (29 HCs, 43 MCI, and 45 PD patients) were assessed for olfaction and anxiety. We used regression models to determine whether B-SIT predicted anxiety and whether sex impacted that relationship. Results: Lower olfaction was related to greater anxiety traits in all groups (HCs: p = 0.015; MCI: p = 0.001 and PD: p = 0.038), significantly differed by sex. In fact, in HCs, for every unit increase in B-SIT, anxiety traits decreased by 7.63 in men (p = 0.009) and 1.5 in women (p = 0.225). In MCI patients for every unit increase in B-SIT, anxiety traits decreased by 1.19 in men (p = 0.048) and 3.03 in women (p = 0.0036). Finally, in PD patients for every unit increase in B-SIT, anxiety traits decreased by 1.73 in men (p = 0.004) and 0.41 in women (p = 0.3632). Discussion: Olfaction and anxiety are correlated in all three distinct diagnostic categories, but differently in men and women. Full article
Show Figures

Figure 1

Back to TopTop