Test-retest reliability and validity of the Importance of Olfaction Questionnaire in Denmark

While measures to detect psychophysical olfactory ability are a crucial part of clinicians' assessment of potential olfactory loss, it gives no indication of how olfaction is experienced by the patient and these different aspects often deviate substantially. To ensure quality and reproducibility of subjectively reported olfactory experience and significance, the Importance of Olfaction Questionnaire (IO-Q) was introduced around a decade ago, and while initial validations have produced promising results, important aspects remain nearly unexamined. For example, the test-retest reliability has rarely been examined and the difference of online versus pen-and-paper administration remains unexplored. Here, we translated IO-Q to Danish and examined its validity, test-retest reliability and mode of administration. A cohort of 179 younger, Danish participants with a high level of English proficiency took the test twice with varying time in-between. The first test was taken digitally and in English, while the second was taken using pen-and-paper and in Danish. The distribution of scores and the relationship between the IO-Q and subscale scores were nearly identical between tests, indicating little to no influence of language/test modality in the sampled population. The internal consistency was comparable to previously published results. Likewise, an acceptable test-retest reliability was observed for the full IO-Q and slightly lower for subscales. No significant effect of time was found across several weeks. In conclusion, the IO-Q performed satisfactorily in all examinations and could therefore serve as a valuable clinical measure of subjective olfactory experience, and its Danish translation shows highly similar characteristics to the original, English version.

Position paper on olfactory dysfunction: 2023

BACKGROUND

Since publication of the original Position Paper on Olfactory Dysfunction in 2017 (PPOD-17), the personal and societal burden of olfactory disorders has come sharply into focus through the lens of the COVID-19 pandemic. Clinicians, scientists and the public are now more aware of the importance of olfaction, and the impact of its dysfunction on quality of life, nutrition, social relationships and mental health. Accordingly, new basic, translational and clinical research has resulted in significant progress since the PPOD-17. In this updated document, we present and discuss currently available evidence for the diagnosis and management of olfactory dysfunction. Major updates to the current version include, amongst others: new recommendations on olfactory related terminology; new imaging recommendations; new sections on qualitative OD and COVID-19 OD; updated management section. Recommendations were agreed by all co-authors using a modified Delphi process.

CONCLUSIONS

We have provided an overview of current evidence and expert-agreed recommendations for the definition, investigation, and management of OD. As for our original Position Paper, we hope that this updated document will encourage clinicians and researchers to adopt a common language, and in so doing, increase the methodological quality, consistency, and generalisability of work in this field.

Developing a core outcome set for clinical trials in olfactory disorders: a COMET initiative

STATEMENT OF PROBLEM

Evaluating the effectiveness of the management of Olfactory Dysfunction (OD) has been limited by a paucity of high-quality randomised and/or controlled trials. A major barrier is heterogeneity of outcomes in such studies. Core outcome sets (COS) -standardized sets of outcomes that should be measured/reported as determined by consensus-would help overcome this problem and facilitate future meta-analyses and/or systematic reviews (SRs). We set out to develop a COS for interventions for patients with OD.

METHODS

A long-list of potential outcomes was identified by a steering group utilising a literature review, thematic analysis of a wide range of stakeholders' views and systematic analysis of currently available Patient Reported Outcome Measures (PROMs). A subsequent e-Delphi process allowed patients and healthcare practitioners to individually rate the outcomes in terms of importance on a 9-point Likert scale.

RESULTS

After 2 rounds of the iterative eDelphi process, the initial outcomes were distilled down to a final COS including subjective questions (visual analogue scores, quantitative and qualitative), quality of life measures, psychophysical testing of smell, baseline psychophysical testing of taste, and presence of side effects along with the investigational medicine/device and patient's symptom log.

CONCLUSIONS

Inclusion of these core outcomes in future trials will increase the value of research on clinical interventions for OD. We include recommendations regarding the outcomes that should be measured, although future work will be required to further develop and revalidate existing outcome measures.

Olfactory Nomenclature: An Orchestrated Effort to Clarify Terms and Definitions of Dysosmia, Anosmia, Hyposmia, Normosmia, Hyperosmia, Olfactory Intolerance, Parosmia, and Phantosmia/Olfactory Hallucination

BACKGROUND

Definitions are essential for effective communication and discourse, particularly in science. They allow the shared understanding of a thought or idea, generalization of knowledge, and comparison across scientific investigation. The current terms describing olfactory dysfunction are vague and overlapping.

SUMMARY

As a group of clinical olfactory researchers, we propose the standardization of the terms "dysosmia," "anosmia," "hyposmia," "normosmia," "hyperosmia," "olfactory intolerance," "parosmia," and "phantosmia" (or "olfactory hallucination") in olfaction-related communication, with specific definitions in this text.

KEY MESSAGES

The words included in this paper were determined as those which are most frequently used in the context of olfactory function and dysfunction, in both clinical and research settings. Despite widespread use in publications, however, there still exists some disagreement in the literature regarding the definitions of terms related to olfaction. Multiple overlapping and imprecise terms that are currently in use are confusing and hinder clarity and universal understanding of these concepts. There is a pressing need to have a unified agreement on the definitions of these olfactory terms by researchers working in the field of chemosensory sciences. With the increased interest in olfaction, precise use of these terms will improve the ability to integrate and advance knowledge in this field.

Long-Term COVID-19 Smell and Taste Disorders Differ Significantly from Other Post-Infectious Cases

INTRODUCTION

COVID-19 is causing a wide range of clinical manifestations. Severe complications and long-lasting sequelae have been identified. Thus, olfactory disorders are reported in up to 86% of cases in mild and moderate COVID-19 infections. We present the first study comparing simple and complex post-COVID-19 cases with matched non-COVID-19 post-infectious smell and taste disorders.

METHODS

A total of 328 patients were recruited from the University Clinic for Flavour, Balance and Sleep, Ear-nose-throat Department, Goedstrup Hospital, Denmark. A non-COVID -19 post-infectious population of 148 individuals was identified from the Redcap database, and was matched by duration of smell and taste disorders. Post-COVID-19 patients were divided into 99 patients with simple smell and taste disorders (only suffering from smell and taste disorders after COVID-19); and (81 patients with complex smell and taste disorder plus several other post-COVID-19 complaints). Besides patient-reported outcome measures (PROM) questionnaires and quality of life score (QoL), ear-nose-throat examination, Mini-Mental State Examination (MMSE), orthonasal smell test (Sniffing's sticks), retronasal quick test, and taste screening were performed.

RESULTS

Cases with post-COVID-19-related smell and taste disorders deviated from non-COVID-19 post-infectious cases; the patients were younger, had a lower occurrence of anosmia/ageusia, and had higher overall smell test scores. In contrast, patients with post-COVID-19-related smell and taste disorders more frequently complained of distorted senses. Parosmia and phantosmia were more prevalent among patients with simple post-COVID-19 complaints than among complex cases and their QoL were more negatively affected.

CONCLUSION

Smell and taste function differ significantly between post-COVID-19 and other non-COVID-19 post-viral cases.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:169-174, 2023.

Development and Psychometric Validation of the Taste And Smell Tool for Evaluation (TASTE) Questionnaire

Importance

The human senses of taste and smell are essential in everyday life. However, as clinical testing of the senses and patient-reported sensory problems are often diverging, additional validated questionnaires are essential for the evaluation of chemosensory impairments.

Objective

To develop an instrument with all relevant domains concerning chemosensory dysfunction and quality of life using modern psychometrics.

Design, Setting, and Participants

The study was designed as a questionnaire study for developing a new instrument. The study started in 2019 and was completed in 2022. Patients with chemosensory dysfunction were recruited from a specialized smell and taste clinic at an ear, nose, and throat department in Denmark. Healthy participants with no history of chemosensory dysfunction were recruited through social media.

Main Outcomes and Measures

Eight domains were included (distorted chemosensation, emotional, food and meals, social, hygiene, danger, work, and relationship), and 35 items were generated based on review of the existing literature and interviews with patients and experts. Participants were tested with the Major Depression Inventory, 36-Item Short Form Health Survey, Taste Sprays, and Sniffin' Sticks for chemosensory function. Descriptive statistics were calculated for all items. Reliability, internal consistency, and validity were investigated, and a Rasch model was fitted. Healthy controls (n = 39) filled out the questionnaire for comparison of known-groups validity. Confirmatory factor analysis was performed. Finally, item reduction was performed, resulting in a final version with 21 items in 8 domains.

Results

The study included responses from 316 patients, 183 women (58%) and 133 men (42%), with a mean (SD) age of 57 (15.1) years. Rasch model fit was acceptable with P > .05 for all items. An 8-dimensional confirmatory factor analysis model showed a better fit than a bifactor confirmatory factor analysis model. Cronbach α ranged from 0.65 to 0.86. Criterion validity with the Sniffin' Sticks, Taste Sprays, Major Depression Inventory, and the 36-Item Short Form Health Survey was satisfactory. The test-retest reliability was good in all domains, ranging from 0.55 to 0.86. All domains were discriminative, except the social and work domains.

Conclusions and Relevance

In this survey study, the instrument was validated with 8 domains related to chemosensory dysfunction and quality of life. All items had good internal consistency, test-retest reliability, interitem correlations, item-total correlations, and Rasch model fit. The questionnaire appears suitable for use in clinical and research settings.

Chemosensory function and food preferences among haemodialysis patients

INTRODUCTION

Malnutrition and disturbed sense of smell and taste frequently occur in patients treated with chronic haemodialysis. The common denominator between chemosensation and nutrition may be food preferences. Our aim was to investigate smell and taste function as well as food preferences among haemodialysis patients and compare the results with those of age-matched controls.

METHODS

An observational case-control study was conducted on 29 patients on chronic haemodialysis and 39 age-matched healthy controls. Chemosensory function was evaluated using validated gustatory and olfactory tests. Food preferences were recorded using a questionnaire of 63 items including a five-point Likert scale of familiarity, liking and frequency.

RESULTS

Chemosensory function was significantly poorer among patients than among controls. Patients had significantly lower familiarity and frequency of consumptions of all food categories than controls and they also had significantly lower liking of vegetables, fruits and starches.

CONCLUSIONS

Implementation of the provided knowledge about haemodialysis patients' smell and taste function including their food preferences are suggested, such as enhancement of odorant intensity, use of taste amplification, cooking habits and exposure to more varied food items. Assessments of food preferences and chemosensory function prior to determination of individual dietary schedules are therefore recommended.

FUNDING

The authors did not receive any financial support for the research or drafting of this article. The authors declare that they have no financial interests to report.

TRIAL REGISTRATION

Danish Ethical Committee project number: M-2018-188-18.

Recovery from 3 Years of Daily Olfactory Distortions after Short-Term Treatment with GABA-Analogue

This case report describes a healthy 47-year-old man with a 3 years history of daily unpleasant olfactory distortions with severe negative effects on the quality of life. The distorted smoke-like smell occurred every day and was most prominent in the evenings resulting in severe discomfort as the patient felt suffocated by the smoke when falling asleep. The distorted smell had no odour triggers and was classified as phantosmia. Patient history, nasal endoscopy, neurological and otolaryngological examination, depression screening, cognitive testing, and CT scan revealed no obvious aetiology, resulting in the diagnosis of idiopathic phantosmia. Quantitate olfactory function was normal. Based on anecdotal evidence in the literature, the patient was treated with a GABA-analogue (pregabalin 50 mg × 3) for 4 weeks. During this treatment, the olfactory distortions completely disappeared for the first time in 3 years and had not reoccurred after 7 months of follow-up. GABA-analogues may be a potential treatment for some of the patients suffering from olfactory distortions. While this constitutes a single case report without controls and phantosmia can disappear spontaneously, there is no proof of causality. However, given the long duration of symptoms, temporal relationship with treatment on the sudden disappearance of phantosmia, and long follow-up without recurrence, this highlights the need for further studies on GABA-analogues as a potential treatment of idiopathic phantosmia. Consequently, larger studies and systematic evaluation of potential effects in different patient groups are warranted before routine treatment with GABA-analogues is advised.

Recovery rates and parosmia in olfactory loss during the COVID-19 era

INTRODUCTION

Olfactory dysfunction (OD) is a common symptom of COVID-19. In some patients, OD persists for many months, fluctuates during recovery or parosmia may occur. Knowledge about the prognosis of these patients is insufficient.

METHODS

Data on chemosensory function and possible prognostic factors were collected through a baseline questionnaire and six follow-up questionnaires answered at 2-3-month intervals.

RESULTS

One year after onset of OD, 42.0% of the respondents reported sustained complete recovery, 41.7% reported partial recovery and 2.4% reported no improvement of olfaction. Follow-up was unavailable for 13.9%. Parosmia, high severity of OD and female sex were associated with lower rates of recovery. Subjects who reported that OD had a high impact on their quality of life were less likely to recover within one month. Smoking, alcohol habits, BMI and physical activity were not associated with persistence of OD.

CONCLUSIONS

High recovery rates were reported within the first months. Recovery of sensory function after more than six months with no prior improvement was reported. After one year, 97.1% of participants with at least one year of follow-up had reported at least some recovery. Recurring OD after initial complete recovery was reported by 24.5% of participants. Parosmia and severity of OD were associated with prolonged recovery rates.

FUNDING

AF received research funding from Velux Fonden. The sponsors had no say nor any responsibilities in relation to the study.

TRIAL REGISTRATION

not relevant.

The Effects of Olfactory Loss and Parosmia on Food and Cooking Habits, Sensory Awareness, and Quality of Life-A Possible Avenue for Regaining Enjoyment of Food

Olfactory dysfunction often has severe consequences on patients’ quality of life. The most common complaint in these patients is their reduced enjoyment of food in both patients with olfactory loss and parosmia. How the different types of olfactory dysfunction differ in relation to food and cooking habits, sensory awareness, and food-related quality of life has not yet received much attention. By applying questionnaires on cooking, food, olfactory function, weight changes, sensory awareness, and food-related quality of life, we investigated how various aspects of eating differ between participants with olfactory loss (n = 271), parosmia (n = 251), and normosmic controls (n = 166). Cooking habits in olfactory dysfunction revealed pronounced differences as compared with normosmic controls. Cooking with olfactory dysfunction was associated with, e.g., a lack of comfort and inspiration for cooking and an inability to make new foods successfully. Significant differences in cooking were also found between olfactory loss and parosmia. Food items were less familiar in participants with olfactory loss and parosmia, while the ratings of liking food items differed between olfactory loss and parosmia, indicating the importance of adapting ingredients in meals separately for olfactory loss and parosmia. Parosmia was associated with a higher incidence of weight loss, but we found no difference in food-related quality of life between participants with olfactory loss and parosmia. While olfactory loss and parosmia have wide-ranging consequences on patients’ cooking and food habits, adapting meals to include ‘safer food items’ and integrating multisensory stimulation may be a possible avenue for improving the enjoyment of food.

Danish Validation of a Retronasal Olfactory Powder Test and Development of a Novel Quick Retronasal Olfactory Test

Introduction  Quality of life is closely linked to retronasal olfactory function. Familiarity with odors vary, so tests need validation. Testing can be time-consuming, so a quick test and a thorough test are needed for clinical and research settings.

Objectives  The objectives of this study were to validate the original retronasal powder olfactory test in a Danish population and to develop a novel quick retronasal test for easy application.

Methods  Ninety-seven participants were included in the study, 59 healthy controls and 38 patients with olfactory impairment. The retronasal test was modified by substituting unfamiliar odors and descriptors and validated with a criterion of correct identification rate of 50% in the original test and 90% in the quick test. Items with over 90% correct identification rate in the modified original test were included in the quick test, resulting in a 10-item test.

Results  The modified retronasal olfactory test achieved good test characteristics, with a 10th percentile cut-off value of 13: sensitivity was 88.9%, specificity 83.0%, positive predictive value 78%, negative predictive value 91.7%, and the receiver operating characteristics area under the curve (ROC-AUC) was 0.86. The quick test achieved acceptable test characteristics, with a 10th percentile cut-off value of 8.2: sensitivity was 72.2%, specificity 90.6%, positive predictive value 83.9%, negative predictive value was 82.8%, and ROC-AUC 0.81.

Conclusion  Validation of both tests demonstrated satisfactory accuracy. We recommend the quick test for screening purposes, and the modified original version for a thorough evaluation. The tests are easily implemented as they are easy to understand and very affordable.

Cortical Atrophy, White Matter Lesions, and Bulb Configuration in Patients with Idiopathic Olfactory Loss and Other Causes of Olfactory Loss

INTRODUCTION

While magnetic resonance imaging (MRI) is not included in the current guidelines for diagnosing olfactory disorders in the most recent position paper on olfactory dysfunction, both 1.5T and 3T MRI are commonly used in the diagnostic workup of many patients with olfactory loss. Often, MRI is used to rule out intracranial tumours, but other useful information may be obtained from MRI scans in these patients. The potential of MRI in olfactory loss depends on sufficient knowledge of structural changes in different aetiologies of olfactory loss. We present common clinical MRI findings in olfactory loss and evaluate the usefulness of structural integrity scores in differentiating between aetiologies.

METHODS

In this study, we investigated if white matter hyperintensities (WMHs, measured by Fazekas score), global cortical atrophy (GCA), and medial temporal lobe atrophy (MTA) are more common in patients with idiopathic olfactory loss than in patients with acquired olfactory loss due to other aetiologies. Furthermore, we compared olfactory bulb (OB) configurations in different olfactory loss aetiologies.

RESULTS

In 88 patients with olfactory loss, WMHs, GCA, and MTA were not more significant findings on MRI in idiopathic olfactory loss (n = 51) compared with other causes of acquired olfactory loss (Fazekas score p = 0.2977; GCA score p = 0.6748; MTA score p = 0.7851). Bulb configurations differed in patients suffering from post-traumatic olfactory loss and may aid in identifying the underlying aetiology in patients where trauma is among the suspected causes of olfactory loss.

CONCLUSION

We recommend that structural MRI with an OB sequence is included in the diagnostic evaluation of olfactory loss with suspected congenital and post-traumatic aetiology and should be considered in idiopathic olfactory loss with suspected central aetiology (e.g., tumour).

Differences in Correlation between Subjective and Measured Olfactory and Gustatory Dysfunctions after Initial Ear, Nose and Throat Evaluation

Introduction  Subjective chemosensory function can differ from measured function. Previous studies on olfactory assessment have found a positive correlation between subjective and measured scores. However, information on gustatory correlation between measured and subjective functions is sparse in patients who have undergone an initial ear, nose and throat (ENT) evaluation.

Objectives  To evaluate the correlation between subjective and measured olfactory and gustatory dysfunctions in a population complaining of taste and/or smell dysfunction after an initial ENT evaluation without chemosensory testing. Furthermore, we aimed to assess the need for chemosensory testing depending on the type of subjective chemosensory dysfunction.

Methods  A case series in which subjective chemosensory function was assessed through a questionnaire and measured chemosensory function was assessed by validated clinical tests.

Results  In total, 602 patients with complaints of olfactory and/or gustatory dysfunction were included. We found that 50% of the patients with normal gustatory function and an olfactory impairment classified their olfactory impairment as a subjective taste disorder. Furthermore, 98% of the patients who rated their olfactory function as absent did have a measurable olfactory impairment, but only 64% were anosmic.

Conclusion  Subjective gustatory dysfunction was poorly correlated with measured gustatory dysfunction, and was often found to reflect olfactory dysfunction. Contrarily, subjective olfactory dysfunction was positively correlated with measurable olfactory dysfunction. Although subjective anosmia was a strong indicator of measured anosmia or hyposmia, the existence of remaining olfactory function was frequently found in these patients. Validated chemosensory testing should be performed in patients with perceived olfactory or gustatory deficits, as this could help ensure increased diagnostic precision and a relevant treatment.

Olfactory groove meningioma with a 10-year history of smell loss and olfactory recovery after surgery

A rare cause of olfactory impairment is olfactory groove meningiomas with insidious onset of non-specific symptoms like headache, olfactory dysfunction, psychiatric symptoms such as depression, personality changes, declining cognitive function, visual disturbances or seizures. A common complication of surgery is loss of olfactory function. Still, the preservation of olfactory function should be attempted as olfactory loss often has a severe negative impact on quality of life. This report describes a woman with an olfactory groove meningioma and a 10-year history of olfactory impairment. It includes preoperatively and postoperatively extended olfactory testing, a neurosurgical approach to preserve the olfactory function and postoperative olfactory rehabilitation. After rehabilitation, the patient regained a normal olfactory function, even though the right-sided olfactory nerve could not be preserved during surgery. The case demonstrates the importance of performing neuroimaging in selected patients with olfactory loss and a method for preserving and potentially improving postoperative olfactory function.

Validation of Olfactory Network Based on Brain Structural Connectivity and Its Association With Olfactory Test Scores

Olfactory perception is a complicated process involving multiple cortical and subcortical regions, of which the underlying brain dynamics are still not adequately mapped. Even in the definition of the olfactory primary cortex, there is a large degree of variation in parcellation templates used for investigating olfaction in neuroimaging studies. This complicates comparison between human olfactory neuroimaging studies. The present study aims to validate an olfactory parcellation template derived from both functional and anatomical data that applies structural connectivity (SC) to ensure robust connectivity to key secondary olfactory regions. Furthermore, exploratory analyses investigate if different olfactory parameters are associated with differences in the strength of connectivity of this structural olfactory fingerprint. By combining diffusion data with an anatomical atlas and advanced probabilistic tractography, we found that the olfactory parcellation had a robust SC network to key secondary olfactory regions. Furthermore, the study indicates that higher ratings of olfactory significance were associated with increased intra- and inter-hemispheric SC of the primary olfactory cortex. Taken together, these results suggest that the patterns of SC between the primary olfactory cortex and key secondary olfactory regions has potential to be used for investigating the nature of olfactory significance, hence strengthening the theory that individual differences in olfactory behaviour are encoded in the structural network fingerprint of the olfactory cortex.

Isolated taste disorders in patients referred to a flavor clinic with taste and smell loss

BACKGROUND AND AIM

Approximately five percent of the general population are suffering from taste disorders. Usually, subjective loss of taste is caused by smell disorders; thus, isolated loss of the sense of taste is relatively rare. Despite the influence on quality of life, isolated taste disorders (ITD) are sparsely represented in literature and clinical research. In particular, there is need for sufficient diagnostic and treatment algorithms. Aim of study is to add further information to the sparse literature on ITD and suggest an appropriate diagnostic algorithm for ITD.

METHODS

We present a retrospective study on patients with ITD diagnosed at the Flavour clinic, ENT department, Regional Hospital West Jutland, between 2017 and 2020. All patients underwent a thorough rhinolaryngological and otoneurologic examination, including olfactory and gustatory assessment, and a wide spectrum of biochemical, microbiological, and radiological examinations.

RESULTS

In total, 522 patients referred due to smell and/or taste disorders, 423 (81%) complained of a subjective taste disorder, only 19 (3.4%) patients were diagnosed with ITD. According to etiology, the patients were categorized in following groups: medicine-related (25%), mixed (21%), iatrogenic (21%), idiopathic (11%), radiotherapy-related (11%), and autoimmune/inflammatory (11%). Based on etiology, individualized treatment was recommended with very discouraging results.

INTERPRETATION

Diagnostics of taste disorders is a delicate and expertise demanding task. The mechanisms underlying isolated loss of taste are heterogeneous. ENT and otoneurologic examination, and specific olfactory and gustatory testing are required in all patients, whereas biochemical, microbiological, and radiological examinations are only necessary on an individual basis.

Sustained Chemosensory Dysfunction during the COVID-19 Pandemic

INTRODUCTION

Chemosensory dysfunction (CD) has proven valuable in prediction of COVID-19, as it is a frequent and specific symptom of the disease. The aim of this study was to investigate the duration of CD in patients with sudden subjective olfactory and/or gustatory loss during the SARS-CoV-2 pandemic. The secondary aim was to identify possible prognostic factors for the duration of CD.

METHODS

An online baseline questionnaire was designed to assess subjective CD. Three rounds of follow-up questionnaires were sent out to any participants with persistent CD in 6-week intervals, prospectively assessing subjective chemosensory function and extending the follow-up time of this cohort significantly.

RESULTS

In total, 467 participants completed the baseline questionnaire. The most significant improvement and recovery of chemosensory function was observed within the first month after the initial loss. Rates became stagnant after about 2 months, and only little improvement and recovery was seen after 2-4 months. After a mean follow-up of 95.9 days (olfactory dysfunction) and 94.0 days (gustatory dysfunction), 86.7% of participants reported gustatory improvement and 82.6% reported olfactory improvement, while 55.0% reported full gustatory recovery and 43.8% reported full olfactory recovery. Female gender was associated with better improvement of gustatory function. High subjective severity of chemosensory loss was associated with lower rates of olfactory and gustatory recovery as well as improvement of olfactory function. Young age was not associated with a better prognosis.

DISCUSSION/CONCLUSION

Rates of improvement and recovery of chemosensory function decreased after 2-4 months after initial chemosensory loss, possibly indicating that prolonged and perhaps permanent chemosensory loss may be a complication of SARS-CoV-2 infections. High subjective severity of CD may worsen the prognosis for improvement and recovery of chemosensory function.

Superficial Parotidectomy: Impact of Postoperative Drainage

BACKGROUND

Use of suction drain after superficial parotidectomy (SP) is based on national consensus considered best practice, but there is no evidence on the effect of the treatment. The aim of the present study is to evaluate the effectiveness of drainage after SP by evaluating the rate of complications after SP in relation to the (ie, duration) of drainage and tumor size.

METHODS

Retrospective analysis was performed involving data from all consecutive patients undergoing SP at the Ear, Nose, and Throat department, Regional Hospital West Jutland, Denmark, between January 1, 2011, and December 31, 2017. Demographics including comorbidity, medication, tumor size, postoperative secretion through the drainage, as well as complications (hematoma, seroma, infection, fistulas, Frey syndrome, facial nerve palsy) were registered. Patients with secretion below 25 mL were compared to patients with secretion above 25 mL, that is, drainage less than 24 hours versus longer than 24 hours. Results: Two hundred five consecutive patients undergoing SP were enrolled. The overall risk of postoperative infection was 16.2%. Ten of 33 patients with infection were also diagnosed with an hematoma or seroma. The risk of infection increased with secretion above 25 mL (27.2%) compared to patients with less than 25 mL (13.1%; P = .0318). The same accounts for the risk of seromas/hematomas (P = .0055). We found no evidence that demographics or comorbidity correlated to the secretion in the drainage, but there is a tendency toward male gender having a higher risk off secretion above 25 mL (odds ratio 1.39).

CONCLUSION

Overall, the risk of complications after SP increased with secretion beyond 25 mL (ie, drainage for more than 24 hours). This applied in particular to infections and seromas/hematomas demanding treatment. The use of routine drainage after SP is questionable, and a randomized trial is warranted to unravel the necessity of postoperative drainage.

Prolonged complaints of chemosensory loss after COVID-19

INTRODUCTION

Chemosensory loss is a common symptom of coronavirus disease 2019 (COVID-19) and has been associated with a milder clinical course in younger patients. Whereas several studies have confirmed this association, knowledge about the improvement and recovery of olfactory and gustatory loss is lacking. The aim of this study was to investigate the temporal dynamics of improvement and recovery from sudden olfactory and gustatory loss in patients with confirmed and suspected COVID-19.

METHODS

Subjective chemosensory function, symptoms of COVID-19, COVID-19 tests results, demographics and medical history were collected through a questionnaire.

RESULTS

Among the 109 study participants, 95 had a combined olfactory and gustatory loss, five participants had isolated olfactory loss and nine participants has isolated taste loss. The mean age of participants was 39.4 years and 25% of participants were under the age of 30 years. Young age was not associated with a higher recovery rate. After a mean time of > 30 days since the chemosensory loss, participants reported relatively low recovery and improvement rates. For participants with olfactory loss, only 44% had fully recovered, whereas 28% had not yet experienced any improvement of symptoms. After gustatory loss, 50% had fully recovered, whereas 20% had not yet experienced any improvement. Olfactory and gustatory deficits were predominantly quantitative and mainly included complete loss of both olfactory and gustatory function.

CONCLUSIONS

Chemosensory loss was frequent in young individuals and persisted beyond a month after symptom onset, often without any improvement during this time.

FUNDING

The author wishes to acknowledge research salary funding from Arla Foods (Viby, Denmark) and the Central Region Denmark. The sponsors had no say, roles or responsibilities in relation to the study, including (but not limited to) the study design, data collection, management and analysis.

TRIAL REGISTRATION

not relevant.

[Anosmia and ageusia as primary symptoms of COVID-19]

This case report describes a physician in the early 30ies with subjective anosmia and ageusia as the major presenting symptoms of COVID-19. Apart from a week of slightly runny nose when coming from cold to warm air, the only symptom was a sudden onset of persistent anosmia and ageusia. Two weeks after normalisation of the mild sino-nasal symptoms, the patient was tested positive for SARS-CoV-2, and anosmia was verified with Sniffin' Sticks tests. Hypogeusia was verified with taste screening and two validated taste tests. Olfactory and gustatory loss may be underestimated symptoms of COVID-19.

The Impact of Acoustic fMRI-Noise on Olfactory Sensitivity and Perception

Sensory perception is neither static nor simple. The senses influence each other during multisensory stimulation and can be both suppressive and super-additive. As most knowledge of human olfactory perception is derived from functional neuroimaging studies, in particular fMRI, our current understanding of olfactory perception has systematically been investigated in an environment with concurrent loud sounds. To date, the confounding effects of acoustic fMRI-noise during scanning on olfactory perception have not yet been investigated. In this study we investigate how acoustic noise derived from the rapid switching of MR gradient coils, affects olfactory perception. For this, 50 subjects were tested in both a silent setting and an fMRI-noise setting, in a randomised order. We found that fMRI-related acoustic noise had a significant negative effect on the olfactory detection threshold score. No significant effects were identified on olfactory discrimination, identification, identification certainty, hedonic rating, or intensity rating.