Olfactory Disturbance Research Articles

Factors associated with SARS-CoV-2 infection in patients attending an acute hospital ambulatory assessment unit.

To describe the factors associated with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection in mild‐to‐moderate patients attending for assessment. This observational study was conducted in a Model 4 tertiary referral center in Ireland. All patients referred for SARS‐CoV‐2 assessment over a 4‐week period were included. Patient demographics, presenting symptoms, comorbidities, medications, and outcomes (including length of stay, discharge, and mortality) were collected. Two hundred and seventy‐nine patients were assessed. These patients were predominantly female (62%) with a median age of 50 years (SD 16.9). Nineteen (6.8%) patients had SARS‐CoV‐2 detected. Dysgeusia was associated with a 16‐fold increased prediction of SARS‐CoV‐2 positivity (p = .001; OR, 16.8; 95% CI, 3.82–73.84). Thirteen patients with SARS‐COV‐2 detected (68.4%) were admitted, in contrast with 38.1% (99/260) of patients with SARS‐CoV‐2 non‐detectable or not tested (p = .001). Female patients were more likely to be hospitalized (p = .01) as were current and ex‐smokers (p = .05). We describe olfactory disturbance and fever as the main presenting features in SARS‐CoV‐2 infection. These patients are more likely to be hospitalized with increased length of stay; however, they make up a minority of the patients assessed. “Non‐detectable” patients remain likely to require prolonged hospitalization. Knowledge of predictors of hospitalization in a “non‐detectable” cohort will aid future planning and discussion of patient assessment in a SARS‐CoV‐2 era.

Interrelation of visual and olfactory impairments in schizophrenia

IntroductionIn schizophrenia, there are disorders in all sensory modalities, but the regularities of their occurrence, their pathogenesis and attitude towards cognitive functions are not sufficiently studied.ObjectivesExamine the interrelation between the dysfunctions in different analysers (olfactory and visual) and their dependence on the duration of the disease and the severity of psychotic symptoms and cognitive deficit in schizophrenic patients (F20 according to ICD 10 criteria).MethodsAll subjects were determined the threshold of olfactory sensitivity to n-butanol, the ability to discriminate against odors and the amount of error in comparing the same sections. Cognitive functions were evaluated using the BACS scale.ResultsThe inverse correlation between the value of the visual assessment error and the reduction of the threshold of olfactory sensitivity (r=- 0.56; p < 0.05) and the inverse correlation between the value of the visual assessment error and the ability to discriminate smells (0.64; p < 0.05) were revealed. There are no significant correlations between the duration of the disease and sensory disturbances. Olfactory and visual disturbances in schizophrenic patients were connected with cognitive functions ((r=-0,62; p< 0,05 and r=-0,84, p< 0,001 accordingly).ConclusionsThe data confirm that sensory impairments have a common pathogenesis and are closely related to cognitive deficits. Sensory and cognitive deficits in schizophrenia may be the result of top-down regulation failure.DisclosureNo significant relationships.

Zaburzenia zmysłu węchu

Węch jest podstawowym zmysłem zarówno u ludzi, jak i u zwierząt. Pozwala kręgowcom i innym organizmom wyposażonym w receptory węchowe rozpoznawać pożywienie, niebezpieczeństwo i dostarcza zmysłowej przyjemności. Zaburzenia lub utrata zmysłu węchu występują w schorzeniach, którym towarzyszy upośledzona drożność nosa, takich jak: przewlekłe zapalenie zatok przynosowych, przewlekłe zapalenie zatok przynosowych z polipami nosa, alergiczny nieżyt nosa, infekcja dróg oddechowych, w tym ostre zapalenie zatok przynosowych. W przypadku zapalenia zatok przynosowych zaburzenia węchu są jednym z czterech głównych objawów choroby. Zaburzenia węchu mogą być również wywołane przez uszkodzenie neuronu węchowego, np. w przebiegu infekcji wirusowej. Utrata węchu i/lub smaku zgłaszana przez chorych na COVID-19 ma istotne znaczenie kliniczne; ułatwia jak najwcześniejszą identyfikację zakażonych do izolacji, jeśli dostęp do badań jest ograniczony, oraz ułatwia kwalifikację do ukierunkowanych testów. W leczeniu zaburzeń i utraty węchu wywołanych przez upośledzenie drożności nosa (lub towarzyszących chorobom przebiegającym z upośledzeniem drożności nosa) stosuje się nowoczesne glikokortykosteroidy donosowe.

Effect of oral steroids on olfactory function in chronic rhinosinusitis with nasal polyps

AimsThe present study aimed to investigate the effects of oral steroids on olfactory disturbances in patients with chronic rhinosinusitis with nasal polyps (CRSwNP). Material and methodsThis is a prospective randomized non-blinded study. Selected CRSwNP patients (n=140), with hyposmia, were devided into two groups; group A received a 7-day course of oral steroids with a 12-weeks course of nasal steroids and douching; group B received a 12-weeks course of nasal steroids and douching. Assessment included Sniffin’ Sticks scores, visual analogue scale score for olfaction and discomfort (VASsmell, VASdis), the Sinonasal Outcome Test-22, Greek-version (SNOT22-Gr) and the endoscopic appearance (EAS). ObjectivesThe main objective was to compare the olfactory effect of the different therapy in group A and group B, at 2, 12 and 24 weeks. Accessory objectives included the comparison of EAS, VASdis and SNOT22-Gr between groups, the evaluation of the therapeutic outcome duration, and, the investigation of potential correlation between the evaluated parameters. ResultsThe 2-weeks evaluation showed a significant statistical difference (P<0.001) for all parameters except VASdis. Olfactory outcomes (Sniffin’ Sticks and VASsmell scale scores) were found significantly better in group A at the 24-weeks evaluation (P<0.001). Within groups, the therapeutic result remained stable between the 12-weeks and 24-weeks evaluation (P>0.05). Sniffin’ Sticks score was strongly correlated at 12-weeks evaluation with EAS (rho=0.58, P<0.001). ConclusionOur results suggest that a combination treatment of oral and nasal steroids in well-selected patients with CRSwNP may result in early olfaction restoration with a possible long-term effect.

Associations between probable REM sleep behavior disorder, olfactory disturbance, and clinical symptoms in Parkinson’s disease: A multicenter cross-sectional study

Rapid eye movement sleep behavior disorder (RBD) and olfactory dysfunction are useful for early diagnosis of Parkinson's disease (PD). RBD and severe olfactory dysfunction are also regarded as risk factors for cognitive impairment in PD. This study aimed to assess the associations between RBD, olfactory function, and clinical symptoms in patients with PD. The participants were 404 patients with non-demented PD. Probable RBD (pRBD) was determined using the Japanese version of the RBD screening questionnaire (RBDSQ-J) and the RBD Single-Question Screen (RBD1Q). Olfactory function was evaluated using the odor identification test for Japanese. Clinical symptoms were evaluated using the Movement Disorder Society Revision of the Unified PD Rating Scale (MDS-UPDRS) parts I-IV. In total, 134 (33.2%) patients indicated a history of pRBD as determined by the RBD1Q and 136 (33.7%) by the RBDSQ-J based on a cutoff value of 6 points. Moreover, 101 patients were diagnosed as pRBD by both questionnaires, 35 by the RBDSQ-J only, and 33 by the RBD1Q only. The MDS-UPDRS parts I-III scores were significantly higher and disease duration significantly longer in the pRBD group. pRBD was significantly associated with male gender and the MDS-UPDRS part I score. The olfactory identification function was significantly reduced in the pRBD group. About 33% of the patients with PD had pRBD based on the questionnaires, and both motor and non-motor functions were significantly decreased in these patients. These results suggest that more extensive degeneration occurred in patients with non-demented PD with RBD.

Spectrum of Non-Motor Symptoms in Parkinson's Disease.

Parkinson's disease is predominantly classified as a movement disorder. Beyond the textbook definition of rigidity, tremors, and bradykinesia, Parkinson's disease encompasses an entire entity of non-motor symptom complexes that can precede the motor features by many years. Despite their significant clinical importance, the awareness of non-motor symptoms is quite negligible. Sleep disorders, gastrointestinal dysfunction, olfactory disturbances, anxiety, and depressive episodes are some of the most common non-motor presentations. The wide-spread occurrence of olfactory symptoms and the low cost of the assessment, is favoring olfactory dysfunction as a potential biomarker in Parkinson's. Sleep disorders may manifest before the motor and autonomic symptoms and might be linked to concomitant sleeping disorders like insomnia, REM sleep disorders, restless leg syndrome, narcolepsy, or obstructive sleep apnea. Non-motor symptoms can deteriorate the quality of life in Parkinson’s patients. Early detection of non-motor symptoms can help in the diagnosis of Parkinson’s disease and can fairly improve the survival and prognosis of these patients.

Insula and Olfaction: A Literature Review and Case Report

(1) Background: It is well established that the insula is involved in olfaction, though its specific role in olfactory processing remains uncertain. In this paper, we first review the current literature on the insula and olfaction. Then, we describe the case of a 56-year-old man with a left insular cavernoma that caused olfactory disturbances. (2) Results: Structural neuroimaging studies suggest that insular gray matter volume is related to olfactory function, and functional neuroimaging shows that various types of stimuli lead to either lateralized or bilateral insular activations. Studies using electro-cortical stimulation reveal a specific region of the insular cortex, around the central insular sulcus, that could be related to unpleasant odor processing. Previous cases of insular lesions leading to olfactory disturbances suggest that left-sided insular lesions may more frequently lead to olfactory changes. In our patient with a left insular cavernoma, odors that were previously perceived as pleasant started smelling unpleasant and were hard to distinguish. Despite these subjective complaints, olfactory function assessed with the Sniffin’ Sticks test was normal. (3) Conclusions: Current tests may not be sensitive to all types of olfactory impairments associated with insular damage, and further studies should be conducted to develop olfactory tests assessing the hedonic appreciation of odors.

Olfactory Dysfunction in COVID-19 Patients: Findings from a Tertiary Rural Centre.

Olfactory and/or taste dysfunction are potential neurological manifestations of coronavirus disease -2019 (COVID-19). The aim of the study was to document the prevalence of anosmia in COVID-19 positive patients and analyze the effect of various factors on the occurrence of these chemosensory dysfunction in the local population. Tertiary referral center. Prospective Study. 250 subjects who tested positive for SARS-CoV-2, by real-time polymerase chain reaction (RT-PCR) and admitted in Isolation ward were enrolled for the study. Data was collected from the subjects via oral questionnaire method, based on the AAO-HNS Anosmia Reporting Tool. Data was collected regarding the age, gender, olfactory or gustatory disturbances, history of recent travel or contact with a positive case, smoking, any associated symptoms, any co-morbid conditions and recovery time of sense of olfaction. Out of 250, 179 (71.6%) subjects were diagnosed with Olfactory dysfunction out of which majority were males, 105 (58.6%). Most of the patients were above 40 years of age (n = 184, 73.6%). Majority of the individuals (88 patients) had close contact with a positive case in recent past, followed by 67 patients who were health care workers, hence proving that risk of infection increases with exposure. Anosmia was present in 68.5% of all the 127 non-smokers. 66.4% had both olfactory as well as gustatory dysfunction whereas 18 patients (7.2%) were found to be totally asymptomatic. Mostly patients recovered their sense of smell within 1–2 weeks from the day of onset of anosmia. Presence of olfactory dysfunction of any degree with or without alteration in taste sensation should raise a suspicion of COVID-19 infection, especially when other classical signs are not present. In such conditions, swabs should be sent for confirmation by RT-PCR testing and till results are awaited, the individual should be shifted to quarantine facilities or advised strict self-isolation.

Psychophysical Evaluation of the Olfactory Function: European Multicenter Study on 774 COVID-19 Patients.

Background: The objective evaluation of the olfactory function of coronavirus disease 2019 patients is difficult because of logistical and operator-safety problems. For this reason, in the literature, the data obtained from psychophysical tests are few and based on small case series. Methods: A multicenter, cohort study conducted in seven European hospitals between March 22 and August 20, 2020. The Sniffin-Sticks test and the Connecticut Chemosensory Clinical Research Center orthonasal olfaction test were used to objectively evaluate the olfactory function. Results: This study included 774 patients, of these 481 (62.1%) presented olfactory dysfunction (OD): 280 were hyposmic and 201 were anosmic. There was a significant difference between self-reported anosmia/hyposmia and psychophysical test results (p = 0.006). Patients with gastroesophageal disorders reported a significantly higher probability of presenting hyposmia (OR 1.86; p = 0.015) and anosmia (OR 2.425; p < 0.001). Fever, chest pain, and phlegm significantly increased the likelihood of having hyposmia but not anosmia or an olfactory disturbance. In contrast, patients with dyspnea, dysphonia, and severe-to-critical COVID-19 were significantly more likely to have no anosmia, while these symptoms had no effect on the risk of developing hyposmia or an OD. Conclusions: Psychophysical assessment represents a significantly more accurate assessment tool for olfactory function than patient self-reported clinical outcomes. Olfactory disturbances appear to be largely independent from the epidemiological and clinical characteristics of the patients. The non-association with rhinitis symptoms and the high prevalence as a presenting symptom make olfactory disturbances an important symptom in the differential diagnosis between COVID-19 and common flu.

Olfactory Disturbances as Presenting Manifestation Among Egyptian Patients with COVID-19: Possible Role of Zinc.

COVID-19 is a severe acute respiratory syndrome caused by coronavirus 2 (SARS-CoV-2). Deficiency of zinc has been supposed to contribute to loss of smell and taste in COVID-19 patients. Our study aimed to assess the serum zinc levels among patients with COVID-19 of various severities, with and without olfaction dysfunction, and to evaluate the effect of zinc therapy in recovery of smell dysfunction among such patients. This study included 134 patients; real-time reverse transcription-polymerase chain reaction (rRT-PCR) proved SARS-CoV-2. Serum zinc levels were measured for all infected patients. One hundred and five patients were detected to have anosmia and/or hyposmia and were categorized randomly into 2 groups; the first group included 49 patients who received zinc therapy and the second group included 56 patients who did not received zinc. All patients were followed up for the recovery duration of olfactory and gustatory symptoms and duration of complete recovery of COVID-19. Olfactory dysfunction was reported in 105 patients (78.4%). Serum zinc levels were not significantly different between the patient subgroups regarding disease severity or the presence or absence of olfactory and/or gustatory dysfunction (p ˃ 0.05). The median duration of recovery of gustatory and/or olfactory function was significantly shorter among patients who received zinc therapy than those who did not received zinc (p < 0.001), while the median duration of complete recovery from COVID-19 was not significantly different among the two groups (p ˃ 0.05). Although the zinc status of COVID-19 patients did not exhibit a significant role in development of anosmia and/or hyposmia or disease severity, zinc therapy may have a significant role in shortening the duration of smell recovery in those patients without affecting the total recovery duration from COVID-19.

The Role of Pain Receptors in the Main Symptoms of Covid-19 and How Diet Can Be a Therapy

It is estimated that 80% of SARS-CoV-2 patients have olfactory disturbances and many also have dysgeusia or ageusia (an interruption or loss of taste, respectively) or changes in chemesthesis, the ability to perceive irritants by TRP receptors. Anosmia (loss of sense of smell) and dysgeusia been termed 'sentinel symptoms'. Anosmia and ageusia represent a real health risk and can also cause nutritional deficits'. Infection with SARS-CoV-2 in the oral cavity could cause changes in the production or quality of saliva, contributing to the symptoms of taste loss. Since the activation of TRPs by Reactive Oxygen Species (ROS) contributes to inflammation and pain, research is focusing on several biological mediators related to TRPs and oxidative radicals that could help the development of treatments for pain itself and some COVID related symptoms. Recent studies have found that Nuclear Factor Erythroid-Related Factor 2 (NRF2) is a transcription factor that regulates cellular defence against toxic and oxidative insults. Compounds that can activate or induce NRF2 include garlic H2S polysulphides, cinnaldehyde in cinnamon, polyphenols in green tea, curcumin, a polyphenolic compound found in curcuma, piperine, an alkaloid found in black pepper, and glucoraphanin found in broccoli. In addition, there is a substantial electrophilic interaction between NRF2, TRPA1 and TPV1 that results in their desensitisation. TRPV1 receptors enter a refractory state (commonly called desensitisation) that leads to inhibition of receptor function as repeated stimulation leads to a progressive reduction in their response. To counteract some of the effects induced by SARS-CoV-2, a rapid desensitisation of TRPs by certain foods is therefore proposed which could reduce the severity of symptoms (including cough, loss of taste and smell) and provide new therapeutic strategies.

The odor stick identification test for Japanese (OSIT-J) in a case of coronavirus disease 2019 (COVID-19) without pneumonia

Anosmia is a frequently experienced symptom in coronavirus disease 2019 (COVID-19). Previous studies have suggested the potential use of olfactometry to identify infected individuals. We performed a sequential olfactometry using the odor stick identification test for Japanese (OSIT-J) in a COVID-19 patient without pneumonia. The test uses 12 odorants that are familiar to the Japanese population. Our patient was a 56-year-old man diagnosed with COVID-19 who was admitted to our hospital following the development of anosmia. He had no respiratory symptoms except pharyngeal pain. Chest CT findings did not reveal the presence of pneumonia. The patient underwent OSIT-J on the 1st hospital day, and his score was 1 out of 12. Following the olfactometry, ciclesonide was administered. The patient did not develop any new symptoms during hospitalization, and his anosmia was gradually improved. The OSIT-J scores were 9 and 11 on the 7th and 16th hospital day, respectively. The patient was discharged on the 25th hospital day after two negative PCR test results. In our case, OSIT-J could identify anosmia in a COVID-19 patient. Some COVID-19 patients are asymptomatic, expect for olfactory disturbances, and OSIT-J may help identify such patients in the Japanese population.

Quick Olfactory Sniffin’ Sticks Test (Q-Sticks) for the detection of smell disorders in COVID-19 patients

BackgroundCoronavirus disease (COVID-19) infection represents a worldwide critical health burden from the sanitary perspective. This disease's symptoms range from a mild flu-like form to a severe life-threatening respiratory disease and respiratory failure. Several patients, however, remain paucisymptomatic. Among the symptoms that seem relevant are the changes in taste and smell, regardless of the disease's severity. MethodsData from patients affected by COVID-19 infection, hospitalized from 15 to 29 April, 2020, were analyzed. Questionnaires about smell, taste, and nasal function were administered to all, and a proportion also received the Quick olfactory Sniffin’ Sticks Test (q-Sticks) to objectivate the presence of anosmia or hyposmia. The results of instruments and Q-Sticks were then compared. ResultsThirty-seven patients (20 males, 54.1%), with a mean age 0f 69.19 years (SD = 17.96; median 76, IQR: 63–82) were evaluated. Among the patients, 8 (22%) were asymptomatic. Out of the remaining 29 patients, 28 (97%) had fever, 19 (66%) asthenia, 11 (38%) dry cough, 10 (34%) dyspnea, and 6 (21%) gastroenteric symptoms. The q-Sticks test was performed on 27 patients and showed that 6 with anosmia, and 16 patients had hyposmia, where only 5 (14%) patients complained of loss of smell by conducting the questionnaires. ConclusionAlthough olfactory disturbances may be secondary to other factors, a sudden onset of anosmia or hyposmia should be assessed as a possible symptom of COVID-19 infection. The use of questionnaires or anamnestic collection is sometimes not enough, while adding to them a simple test such as the q-Sticks test can provide more accurate and reliable data. A simple, easy-to-perform, and reliable tool (q-Sticks) for olfactory disorders assessment can be administered to identify the real size of anosmia in patients with COVID-19 infection and detect the early stage of infection or paucisymptomatic patients, therefore becoming important to reduce the spreading of the pandemic.

Smell and taste loss in COVID-19 patients: assessment outcomes in a Victorian population

Background: It has been noted that olfactory and gustatory disturbances may precede or accompany the typical features of COVID-19, such as fever and cough. Hence, a high index of suspicion is required when patients report sudden loss of smell or taste, in order to facilitate timely diagnosis and isolation. Aims/objectives: The aim of this study was to assess the frequency of olfactory and gustatory disturbances in COVID-19 positive patients from a cohort representative of Melbourne, Australia. Methods: A retrospective descriptive study was conducted on patients who tested positive for COVID-19. Standardised phone consultations and online follow-up questionnaires were performed to assess clinical features of COVID-19, with a focus on smell and taste disorders. Results: The most frequent symptoms experienced were taste and smell disturbances with 74% experiencing either smell or taste disturbance or both. Post-recovery, 34% of patients continued to experience ongoing hyposmia and 2% anosmia, whereas 28% continued to suffer from hypogeusia or ageusia. Conclusion and significance: This study presents the high rates of improvement of both olfactory and gustatory disturbance in a short-lived period. It also highlights the importance of these symptoms in prompting appropriate testing, quarantine precautions, initiate early olfactory retraining and the potential for continued sensory disturbance.

High Serum Tumor Necrosis Factor Receptor 1 Levels Are Related to Risk of Low Intrinsic Capacity in Elderly Adults.

To explore the association between inflammatory cytokines and intrinsic capacity in older adults. Data were retrieved from the Cardiovascular Health, Cognition and Aging Study. A total of 130 participants aged 60-99 years (mean age 73.11±9.02 years) were recruited. Intrinsic capacity was assessed by the five domains recommended by the World Health Organization: locomotion, cognition, vitality, sensory and psychological domains. Circulating interleukin-6, tumor necrosis factor receptor 1 (TNFR1), insulin-like growth factor-1, and vaspin levels were measured. Logistic regression was conducted for factors associated with intrinsic capacity decline. Intrinsic capacity decline was associated with older age, kidney diseases, olfactory disturbances and lower grip strength. Logistic regression showed that circulating TNFR1 was independently associated with intrinsic capacity decline after adjustments for age, sex, education, chronic diseases, grip strength, and physical activity. Elevated circulating TNFR1 levels are independently associated with declined intrinsic capacity, suggesting that chronic inflammation may underlie intrinsic capacity decline.

Long-term olfactory dysfunction after single-nostril endoscopic transnasal transsphenoidal pituitary adenoma surgery

BackgroundOver the past decade, the endoscopic transnasal transsphenoidal approach for pituitary adenomas has been widely adopted among neurosurgeons. However, olfactory disturbances have been observed after this procedure, and few studies on long-term (>6 mo) olfactory disturbance after endoscopic transnasal transsphenoidal pituitary adenoma surgery have been conducted. Although we perform minimally invasive endoscopic surgery, some patients continue to experience hyposmia, with some even experience long-term hyposmia. This impairment results in a considerable loss in quality of life. We present a series of patients who underwent minimally invasive single-nostril TSS for pituitary adenoma, including evaluation of their olfactory function. We further investigated the related risk factors for long-term olfactory dysfunction. MethodsOne hundred sixty-one consecutive patients who met the study criteria underwent the single-nostril endoscopic transsphenoidal approach by the senior author. The Smell Diskettes Olfaction Test was used to evaluate olfactory function. ResultsPostoperative olfactory disturbance in patients treated with endoscopic transnasal TSS is frequent. Of the study population, 67.1% of the patients were hyposmic or anosmic and 14.9% had long-term olfactory dysfunction. We also performed multivariate logistic regression analysis to compare the characteristics of patients with long-term olfactory dysfunction. Nasal symptoms (odds ratio [OR], 6.77) and smoking (OR, 14.77) were associated with long-term olfactory dysfunction after transnasal TSS. ConclusionsSignificant disturbances in olfactory performance occur after single-nostril transnasal TSS for pituitary adenoma. Furthermore, preoperative nasal disease and smoking appear to be risk factors for long-term olfactory dysfunction. Physicians should address clinical findings related to olfactory function and provide appropriate care.

Using Anti-SARS-CoV-2 IgG and IgM Antibodies to Detect Outpatient Cases with Olfactory and Taste Disorders Suspected as Mild Form of COVID-19: a Retrospective Survey.

Many patients with olfactory disorders were referred during the COVID-19 pandemic in 2020. The aim of this study was to detect outpatient cases with olfactory and taste disorders suspected to mild form of COVID-19 disease in Gorgan city in the north of Iran retrospectively. This study was performed on patients who had the complaints of olfactory disorders during 03/01/2020 to 04/01/2020. They also had the mild symptoms of upper respiratory tract infection. The control group included patients who had similar symptoms during this period but did not report olfactory or taste disturbances. Due to the limitations of serologic kits, this study was performed 2–3 months after the onset of symptoms. The number of patients and controls was 72 and 36 respectively. The range and the mean ± SD of patient’s age were 21–63 and 39.82 ± 9.82 years. In both groups, 44.44% were male and 55.56% were female. The time interval between the onset of symptoms and the serologic tests in both groups was 91.11 ± 16.20 days. In the cases and controls, the IgG titer was positive in 44.4% and 22.2% and the IgM titer was positive in 5.6% and 8.3% respectively. IgG antibody titers were higher in cases than in the control group (P = 0.024). There was no correlation among antibody titers and the severity of olfactory disturbances, the gender, and the age. The high COVID-19 IgG antibody titer in patients with olfactory disorder during the pandemic can probably be considered as a warning complaint of COVID-19 and may be used for isolation plans.

Is SARS-CoV-2 (COVID-19) postviral olfactory dysfunction (PVOD) different from other PVOD?

BackgroundThe SARS-CoV-2 virus continues to spread rapidly across the globe afflicting many with Coronavirus Disease 2019 (COVID-19). As the infection rates rise, a growing number of SARS-CoV-2 positive individuals have been reported to complain of olfactory disturbances at an alarming rate. Postviral olfactory dysfunction (PVOD) is a well-known phenomenon that may explain the olfactory dysfunction reported by SARS-CoV-2 infected individuals.MethodsA scoping literature review was performed to identify studies that investigated the mechanisms of postviral olfactory dysfunction. Studies demonstrating pathophysiological, histological, immunochemical, and epidemiological outcomes of PVOD were included.ResultsFourteen studies were included in addition to one international news article. Three studies reported destruction of the olfactory epithelium following intranasal inoculation of various viral strains in mice. Three studies isolated pathogenic, anosmia inciting viruses (Parainfluenza virus, Human Coronavirus, Rhinovirus) through nucleic acid amplification. Eleven studies demonstrated female predilection in patients with PVOD and COVID-19 associated olfactory dysfunction, of which the majority were over 50 years old.ConclusionsPVOD and COVID-19 associated olfactory dysfunction demonstrates considerable similarities in epidemiological trends and disease sequela of other viruses to suggest identical pathophysiological mechanisms. Further studies such as intranasal inoculation and histological biopsies are needed to support our hypothesis.

Contemporary Analysis of Olfactory Dysfunction in Mild to Moderate Covid 19 Patients in A Tertiary Health Care Centre.

Introduction: The World Health Organization declared COVID-19 a pandemic on March 11, 2020. The virus that causes COVID-19 was designated as severe acute respiratory syndrome corona virus 2 (SARS-CoV-2). Several studies have reported chemosensory dysfunction, such as anosmia and ageusia, as common findings in COVID-19 positive patients. To date, qualitative olfactory testing has been performed only in a very few cohort studies on COVID-19 patients. However, objective testing is necessary to verify or determine the true magnitude of their deficits. Moreover, the proportion of COVID-19 patients exhibiting true olfactory disturbances is unknown. Aim of the Study: To determine the true prevalence of olfactory dysfunction in COVID-19 patients by objective assessment in mild to moderate symptomatic patients. Materials & Methodology: This was a prospective cross-sectional analytical study. All patients who were COVID-19 positive and having mild to moderate symptoms and not admitted in ICU formed part of the study group. Objective evaluation of smell function was done. Results: Self-reported smell dysfunction was present in 26.9% patients (n=62) and taste dysfunction was seen in 10.9% (n=25) of patients. On quantitative assessment of smell dysfunction, it was noted that 41.3% (n=95) of patients had some form of smell dysfunction out of which 70.5% patients (n=67) had hyposmia and 29.5% patients (n=28) had anosmia. Conclusion: Incidence was found to be more by objective assessment when compared to self-reported symptoms.

Objective Sensory Testing Methods Reveal a Higher Prevalence of Olfactory Loss in COVID-19-Positive Patients Compared to Subjective Methods: A Systematic Review and Meta-Analysis.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), has currently infected over 6.5 million people worldwide. In response to the pandemic, numerous studies have tried to identify causes and symptoms of the disease. Emerging evidence supports recently acquired anosmia (complete loss of smell) and hyposmia (partial loss of smell) as symptoms of COVID-19, but studies of olfactory dysfunction show a wide range of prevalence, from 5% to 98%. We undertook a search of Pubmed/Medline and Google Scholar with the keywords “COVID-19,” “smell,” and/or “olfaction.” We included any study that quantified smell loss (anosmia and hyposmia) as a symptom of COVID-19. Studies were grouped and compared based on the type of method used to measure smell loss—subjective measures such as self-reported smell loss versus objective measures using rated stimuli—to determine if prevalence differed by method type. For each study, 95% confidence intervals (CIs) were calculated from point estimates of olfactory disturbances. We identified 34 articles quantifying anosmia as a symptom of COVID-19 (6 objective, 28 subjective), collected from cases identified from January 16 to April 30, 2020. The pooled prevalence estimate of smell loss was 77% when assessed through objective measurements (95% CI of 61.4-89.2%) and 44% with subjective measurements (95% CI of 32.2-57.0%). Objective measures are a more sensitive method to identify smell loss as a result of infection with SARS-CoV-2; the use of subjective measures, while expedient during the early stages of the pandemic, underestimates the true prevalence of smell loss.