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Journal of Neurovirology Apr 2022COVID-19 pandemic spreads worldwide, with more than 100 million positive cases and more than 2 million deaths. From the beginning of the COVID-19 pandemic, several... (Review)
Review
COVID-19 pandemic spreads worldwide, with more than 100 million positive cases and more than 2 million deaths. From the beginning of the COVID-19 pandemic, several otolaryngologists described many cases of a sudden loss of smell (anosmia) associated with the disease with or without additional symptoms. Anosmia is often the first and sometimes the only sign in the asymptomatic carriers of COVID-19. Still, this disorder is underestimated, and it is not life-threatening. However, it significantly decreases the quality of life. This olfactory dysfunction continues in several cases even after the nasopharyngeal swab was negative. The occurrence of anosmia can be used as a screening tool for COVID-19 patients and can be used to identify these patients to accomplish the isolation and tracking procedures. In this review, we highlighted the possible mechanisms of anosmia in COVID-19 patients, major pathologies and features of anosmia, implications of anosmia in early diagnosis of COVID-19, evaluation of the smell function during COVID-19, and management and treatment options of COVID-19 anosmia.
Topics: Anosmia; COVID-19; Humans; Olfaction Disorders; Pandemics; Quality of Life; SARS-CoV-2
PubMed: 35249186
DOI: 10.1007/s13365-022-01060-9 -
Molecular Neurobiology Mar 2021COVID-19, the global threat to humanity, shares etiological cofactors with multiple diseases including Alzheimer's disease (AD). Understanding the common links between... (Review)
Review
COVID-19, the global threat to humanity, shares etiological cofactors with multiple diseases including Alzheimer's disease (AD). Understanding the common links between COVID-19 and AD would harness strategizing therapeutic approaches against both. Considering the urgency of formulating COVID-19 medication, its AD association and manifestations have been reviewed here, putting emphasis on memory and learning disruption. COVID-19 and AD share common links with respect to angiotensin-converting enzyme 2 (ACE2) receptors and pro-inflammatory markers such as interleukin-1 (IL-1), IL-6, cytoskeleton-associated protein 4 (CKAP4), galectin-9 (GAL-9 or Gal-9), and APOE4 allele. Common etiological factors and common manifestations described in this review would aid in developing therapeutic strategies for both COVID-19 and AD and thus impact on eradicating the ongoing global threat. Thus, people suffering from COVID-19 or who have come round of it as well as people at risk of developing AD or already suffering from AD, would be benefitted.
Topics: Acetylcholine; Age Factors; Aged; Aged, 80 and over; Alzheimer Disease; Angiotensin-Converting Enzyme 2; Animals; Anosmia; Apolipoprotein E4; Brain; COVID-19; Cytokine Release Syndrome; Cytokines; Female; Galectins; Humans; Hypoxia; Interleukins; Male; Membrane Proteins; Mice; Receptors, Virus; SARS-CoV-2; Sex Factors; Smoking
PubMed: 33078369
DOI: 10.1007/s12035-020-02177-w -
Iranian Journal of Otorhinolaryngology Jul 2022Olfactory training is accounted as a significantly beneficial therapy for hyposmia or anosmia. There is some evidence about methylxanthine usage for this issue. In the...
INTRODUCTION
Olfactory training is accounted as a significantly beneficial therapy for hyposmia or anosmia. There is some evidence about methylxanthine usage for this issue. In the present study, we have investigated the effects of topical aminophylline in hyposmic and anosmic patients.
MATERIALS AND METHODS
In this clinical trial study, patients were randomly divided into two groups (n= 20/each), the case group was given aminophylline drops over a three-month period (using the contents of the vial aminophylline in the form of nasal drops, 250 micrograms daily) with olfactory training and the control group was given normal saline drops with olfactory training over a three-month period. The olfactory capacities were assessed before the start and after the completion of treatments using a valid and reliable smell identification test.
RESULTS
In the saline and aminophylline groups, the mean ± SD relative changes in SIT score were 0.55±0.31 and 0.85±0.56, respectively. As a result, the SIT score in the saline group climbed by 55 percent but increased by 85 percent in the aminophylline group. The difference in SIT score between pre- and post-test was meaningful in both groups (P< 0.001). The aminophylline group scored significantly higher according to the marginal longitudinal regression model, adjusting baseline parameters.
CONCLUSIONS
Intranasal aminophylline plus olfactory training significantly improved SIT scores in severe hyposmia or anosmia. Hypothetically, these effects are mediated through changes in cAMP and cGMP.
PubMed: 36035646
DOI: 10.22038/IJORL.2022.64064.3195 -
Acta Neurologica Belgica Dec 2023Rapid Eye Movement Sleep Behavior Disorder (RBD) and hyposmia are common in synucleinopathies and they tend to occur in connection to the prodromal development of these...
INTRODUCTION
Rapid Eye Movement Sleep Behavior Disorder (RBD) and hyposmia are common in synucleinopathies and they tend to occur in connection to the prodromal development of these disorders. In this study, we sought to determine the prevalence of RBD and hyposmia and the timeline of their occurrence in a large cohort of Moroccan patients.
METHODS
We recruited 774 consecutive patients with synucleinopathy and tauopathy at Ibn Rochd University Hospital of Casablanca. A group of 100 healthy controls was also recruited. We relied on a questionnaire to collect general characteristics and clinical data filled by the patient and his companion under the supervision of a qualified health professional.
RESULTS
The study included 697 patients with PD, 37 with DLB and 40 had a tauopathy disorder (PSP or CBD). The proportion of patients who have RBD was 52% in PD, 100% in DLB, 0% in tauopathies and 12% among healthy controls. Hyposmia symptom was found in 47% of patients with PD, 68% in patients with DLB, 0% in tauopathy patients and in 10% of healthy controls. Moreover, 46% of PD patients and 75% of DLB patients developed RBD during the prodromal phase. Meanwhile, hyposmia occurred in association with the prodromal phase among 67% of PD cases and 85% of DLB patients.
CONCLUSION
RBD and hyposmia are both prevalent among Moroccan patients with synucleinopathy and they occur frequently during the prodromal phase. Identifying these premotor signs will improve early and differential diagnosis and enhance our understanding of how a specific synucleinopathy progresses.
Topics: Humans; Synucleinopathies; Parkinson Disease; Anosmia; Prevalence; REM Sleep Behavior Disorder; Tauopathies
PubMed: 37046132
DOI: 10.1007/s13760-023-02262-6 -
CMAJ : Canadian Medical Association... Feb 2021
Observational Study
Topics: Adolescent; Alberta; Anosmia; Asymptomatic Infections; COVID-19; COVID-19 Testing; Child; Child, Preschool; Female; Fever; Headache; Humans; Infant; Infant, Newborn; Male; Nausea; Vomiting
PubMed: 33526549
DOI: 10.1503/cmaj.202065-f -
Headache Sep 2020To summarize for the trainee audience the possible mechanisms of headache in patients with COVID-19 as well as to outline the impact of the pandemic on patients with... (Review)
Review
OBJECTIVE
To summarize for the trainee audience the possible mechanisms of headache in patients with COVID-19 as well as to outline the impact of the pandemic on patients with headache disorders and headache medicine in clinical practice.
BACKGROUND
COVID-19 is a global pandemic caused by the novel coronavirus severe acute respiratory syndrome coronavirus 2, of which a large subset of patients features neurological symptoms, commonly headache. The virus is highly contagious and is, therefore, changing clinical practice by forcing limitations on in-person visits and procedural treatments, more quickly shifting toward the widespread adaptation of telemedicine services.
DESIGN/RESULTS
We review what is currently known about the pathophysiology of COVID-19 and how it relates to possible mechanisms of headache, including indirect, potential direct, and secondary causes. Alternative options for the treatment of patients with headache disorders and the use of telemedicine are also explored.
CONCLUSIONS
Limited information exists regarding the mechanisms and timing of headache in patients with COVID-19, though causes relate to plausible direct viral invasion of the nervous system as well as the cytokine release syndrome. Though headache care in the COVID-19 era requires alterations, the improved preventive treatment options now available and evidence for feasibility and safety of telemedicine well positions clinicians to take care of such patients, especially in the COVID-19 epicenter of New York City.
Topics: Aged, 80 and over; Anosmia; COVID-19; Comorbidity; Cytokine Release Syndrome; Education, Medical, Continuing; Headache; Headache Disorders, Secondary; Humans; Inflammation Mediators; Leukoencephalitis, Acute Hemorrhagic; Migraine Disorders; Neurology; New York City; Pandemics; Physical Distancing; SARS-CoV-2; Telemedicine
PubMed: 32521039
DOI: 10.1111/head.13884 -
Laryngo- Rhino- Otologie May 2023The sense of smell is important. This became especially clear to patients with infection-related olfactory loss during the SARS-CoV-2 pandemic. We react, for example, to...
The sense of smell is important. This became especially clear to patients with infection-related olfactory loss during the SARS-CoV-2 pandemic. We react, for example, to the body odors of other humans. The sense of smell warns us of danger, and it allows us to perceive flavors when eating and drinking. In essence, this means quality of life. Therefore, anosmia must be taken seriously. Although olfactory receptor neurons are characterized by regenerative capacity, anosmia is relatively common with about 5 % of anosmic people in the general population. Olfactory disorders are classified according to their causes (e. g., infections of the upper respiratory tract, traumatic brain injury, chronic rhinosinusitis, age) with the resulting different therapeutic options and prognoses. Thorough history taking is therefore important. A wide variety of tools are available for diagnosis, ranging from short screening tests and detailed multidimensional test procedures to electrophysiological and imaging methods. Thus, quantitative olfactory disorders are easily assessable and traceable. For qualitative olfactory disorders such as parosmia, however, no objectifying diagnostic procedures are currently available. Therapeutic options for olfactory disorders are limited. Nevertheless, there are effective options consisting of olfactory training as well as various additive drug therapies. The consultation and the competent discussion with the patients are of major importance.
Topics: Humans; Anosmia; Quality of Life; SARS-CoV-2; COVID-19; Olfaction Disorders
PubMed: 37130532
DOI: 10.1055/a-1957-3267 -
Indian Journal of Otolaryngology and... Oct 2022The present study aimed at evaluating the prevalence of general and sinonasal symptoms in patients with olfactory symptoms and mild coronavirus disease-2019 (COVID-19)...
The present study aimed at evaluating the prevalence of general and sinonasal symptoms in patients with olfactory symptoms and mild coronavirus disease-2019 (COVID-19) and determining the patterns in emergence and resolution of olfactory/gustatory symptoms relative to general and sinonassal symptoms. This was a prospective cross-sectional study conducted at the outpatient otorhinolaryngology clinic at a COVID-19-designated referral Hospital. We included consecutive patients with new-onset olfactory dysfunction and positive polymerase chain reaction (PCR) assay of COVID-19. We asked the patients to fill in a questionnaire about general and sinonasal symptoms in association with anosmia, hyposmia or hypogeusia, and recorded the time course of the olfactory/gustatory symptoms during 2-weeks of follow-up. 76 patients with average age of 38.5 ± 10.6 years were included. Majority of participants (94.7%) had general or sinonasal symptom. There was anosmia in 60.5% and hyposmia in 39.5%, with sudden onset of olfactory symptoms reported in 63.2% of patients. During the follow-up, 30.3% of patients completely and 44.7% partially recovered from anosmia/hyposmia. Regardless of whether the general or olfactory symptoms appeared initially, the general symptoms resolved first while a degree of olfactory dysfunction persisted during the follow-up. Our study showed that hyposmia and anosmia in mild COVID-19 are frequently associated with general and sinonasal symptoms and tend to persist longer than the general and sinonasal symptoms during the course of the disease.
PubMed: 33014751
DOI: 10.1007/s12070-020-02166-4 -
Brazilian Journal of Otorhinolaryngology 2022SARS-CoV-2 is the pathogen of COVID-19. The virus is composed of the spike, membrane and envelope. On physiological smell, odoriferous substances bind to proteins... (Review)
Review
INTRODUCTION
SARS-CoV-2 is the pathogen of COVID-19. The virus is composed of the spike, membrane and envelope. On physiological smell, odoriferous substances bind to proteins secreted by sustentacular cells in order to be processed by olfactory receptor neurons. Olfactory disorder is one of the main manifestations of COVID-19, however, research is still required to clarify the mechanism involved in SARS-CoV-2 induced anosmia.
OBJECTIVE
This article aims to analyze current scientific evidence intended to elucidate the pathophysiological relationship between COVID-19 and the cause of olfactory disorders.
METHODS
Pubmed, Embase, Scopus and ScienceDirect were used to compose this article. The research was conducted on November 24th, 2020. Original articles with experimental studies in human, animal and in vitro, short communications, viewpoint, published in the English language and between 2019 and 2020 were included, all related to the pathophysiological relationship between olfactory disorders and COVID-19 infection.
RESULTS
Both human cell receptors ACE2 and TMPRSS2 are essential for the SARS-CoV-2 entrance. These receptors are mostly present in the olfactory epithelium cells, therefore, the main hypothesis is that anosmia is caused due to damage to non-neuronal cells which, thereafter, affects the normal olfactory metabolism. Furthermore, magnetic resonance imaging studies exhibit a relationship between a reduction on the neuronal epithelium and the olfactory bulb atrophy. Damage to non-neuronal cells explains the average recovery lasting a few weeks. This injury can be exacerbated by an aggressive immune response, which leads to damage to neuronal cells and stem cells inducing a persistent anosmia. Conductive anosmia is not sufficient to explain most cases of COVID-19 induced anosmia.
CONCLUSION
Olfactory disorders such as anosmia and hyposmia can be caused by COVID-19, the main mechanism is associated with olfactory epithelium damage, targeting predominantly non-neuronal cells. However, neuronal cells can also be affected, worsening the condition of olfactory loss.
Topics: Angiotensin-Converting Enzyme 2; Animals; Anosmia; COVID-19; Humans; Olfaction Disorders; SARS-CoV-2; Smell
PubMed: 33965353
DOI: 10.1016/j.bjorl.2021.04.001 -
Neurology Oct 2022To examine associations between olfactory dysfunction, Alzheimer disease (AD) pathology, and motoric cognitive risk syndrome (MCR), a predementia syndrome characterized...
BACKGROUND AND OBJECTIVES
To examine associations between olfactory dysfunction, Alzheimer disease (AD) pathology, and motoric cognitive risk syndrome (MCR), a predementia syndrome characterized by cognitive complaints and slow gait that is associated with risk for AD and other dementias.
METHODS
We conducted a retrospective analysis of a prospective cohort study to examine whether baseline olfactory function was associated with the risk of incident MCR in 1,119 adults aged 60 years and older (75.1% female). The association between performance on the Brief Smell Identification Test (BSIT) and incident MCR risk was computed using Cox models and reported as the hazard ratio (HR) with 95% CIs adjusted for demographic, comorbidity, and cognitive factors. Furthermore, we assessed the relationship between postmortem AD pathology and non-AD pathology and olfactory function at the time of MCR diagnosis using linear regression models adjusted for sex, education, age at death, and time from diagnosis to death.
RESULTS
There were 544 (48.6%) incident cases of MCR over a median follow-up of 3.94 years. Lower BSIT scores (poor olfaction) at baseline were associated with an increased risk of incident MCR (HR for a 1-point increase in BSIT score 0.92; 95% CI 0.88-0.96) in fully adjusted models. Those with hyposmia (scores of ≤8 on the BSIT) at baseline (26.6%) were at an increased risk of MCR (HR 1.44; 95% CI 1.19-1.74) compared with those with normal olfactory function. Higher levels of the composite measure of global AD pathology and presence of Lewy body pathology were associated with lower BSIT scores at the time of incident MCR diagnosis (n = 118). τ tangle density, a specific component of AD pathology, was inversely associated with olfactory function, and the correlation remained after controlling for mild cognitive impairment syndrome and the presence of Lewy body pathology.
DISCUSSION
The results provide evidence that olfactory dysfunction precedes MCR incidence and is related to Alzheimer pathology, providing a clinical approach to risk stratify and subtype MCR.
Topics: Humans; Female; Middle Aged; Aged; Male; Prospective Studies; Incidence; Smell; Retrospective Studies; Cognitive Dysfunction; Alzheimer Disease; Syndrome; Anosmia; Cognition; Risk Factors
PubMed: 36240083
DOI: 10.1212/WNL.0000000000201030