Olfactory dysfunction and COVID-19

Mechanism and treatment of olfactory dysfunction caused by coronavirus disease 2019

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since the start of the pandemic, olfactory dysfunction (OD) has been reported as a common symptom of COVID-19. In some asymptomatic carriers, OD is often the first and even the only symptom. At the same time, persistent OD is also a long-term sequela seen after COVID-19 that can have a serious impact on the quality of life of patients. However, the pathogenesis of post-COVID-19 OD is still unclear, and there is no specific treatment for its patients. The aim of this paper was to review the research on OD caused by SARS-CoV-2 infection and to summarize the mechanism of action, the pathogenesis, and current treatments.

Unravelling Pathophysiology of Neurological and Psychiatric Complications of COVID-19 Using Brain Organoids

Neuropsychiatric manifestations of coronavirus disease 2019 (COVID-19) have been increasingly recognized. However, the pathophysiology of COVID-19 in the central nervous system remains unclear. Brain organoid models derived from human pluripotent stem cells are potentially useful for the study of complex physiological and pathological processes associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as they recapitulate cellular heterogeneity and function of individual tissues. We identified brain organoid studies that provided insight into the neurotropic properties of SARS-CoV-2. While SARS-CoV-2 was able to infect neurons, the extent of neurotropism was relatively limited. Conversely, choroidal epithelial cells consistently showed a high susceptibility to SARS-CoV-2 infection. Brain organoid studies also elucidated potential mechanism for cellular entry, demonstrated viral replication, and highlighted downstream cellular effects of SARS-CoV-2 infection. Collectively, they suggest that the neuropsychiatric manifestations of COVID-19 may be contributed by both direct neuronal invasion and indirect consequences of neuroinflammation. The use of high throughput evaluation, patient-derived organoids, and advent of "assembloids" will provide a better understanding and functional characterization of the neuropsychiatric symptoms seen in post-acute COVID-19 syndrome. With advancement of organoid technology, brain organoids offer a promising tool for unravelling pathophysiologic clues and potential therapeutic options for neuropsychiatric complications of COVID-19.

Long COVID-19 in children: an Italian cohort study

BACKGROUND

Long COVID-19 syndrome is a complex of symptoms that occurs after the acute SARS-CoV-2 infection, in the absence of other possible diagnoses. Studies on Long COVID-19 in pediatric population are scanty and heterogeneous in design, inclusion criteria, outcomes, and follow-up time. The objective of the present study is to assess the prevalence of Long COVID-19 syndrome in a cohort of Italian pediatric primary care patients, observed for a period of time of 8 to 36 weeks from healing. Prevalence was also assessed in a cohort of pediatric patients hospitalized during acute infection.

METHODS

Data concerning 629 primary care patients with previous acute SARS-CoV-2 infection were collected by a questionnaire filled in by Primary Care Pediatrician (PCP). The questionnaire was administrated to patients by 18 PCPs based in 8 different Italian regions from June to August 2021. Data concerning 60 hospitalized patients were also collected by consultation of clinical documents.

RESULTS

Cumulative incidence of Long COVID-19 resulted to be 24.3% in primary care patients and 58% in hospitalized patients. The most frequently reported symptoms were abnormal fatigue (7%), neurological (6.8%), and respiratory disorders (6%) for the primary care cohort. Hospitalized patients displayed more frequently psychological symptoms (36.7%), cardiac involvement (23.3%), and respiratory disorders (18.3%). No difference was observed in cumulative incidence in males and females in both cohorts. Previous diseases did not influence the probability to develop Long COVID-19. The prevalence of Long COVID-19 was 46.5% in children who were symptomatic during acute infection and 11.5% in asymptomatic ones. Children aged 0 to 5 years had a greater risk to develop respiratory symptoms, while adolescents (aged 11-16 years) had a greater risk to develop neurological and psychological Long COVID-19 symptoms.

CONCLUSIONS

Our study demonstrates that Long COVID-19 is a reality in pediatric age and could involve even patients with mild or no acute symptoms. The results stress the importance of monitoring primary care pediatric patients after acute COVID-19 infection and the relevance of vaccination programs in pediatric population, also in order to avoid the consequences of Long COVID-19 syndrome.

A Case Series of Olfactory Dysfunction in Imported COVID-19 Patients: A 12-Month Follow-Up Study

OBJECTIVE

The scientific community knows little about the long-term influence of coronavirus disease 2019 (COVID-19) on olfactory dysfunction (OD). With the COVID-19 pandemic ongoing worldwide, the risk of imported cases remains high. In China, it is necessary to understand OD in imported cases.

METHODS

A prospective follow-up design was adopted. A total of 11 self-reported patients with COVID-19 and OD from Xi'an No. 8 Hospital were followed between August 19, 2021, and December 12, 2021. Demographics, clinical characteristics, laboratory and radiological findings, and treatment outcomes were analyzed at admission. We surveyed the patients via telephone for recurrence and sequelae at the 1-, 6-, and 12-month follow-up.

RESULTS

Eleven patients with OD were enrolled; of these, 54.5% (6/11) had hyposmia and 45.5% (5/11) had anosmia. 63.6% (7/11) reported OD before or on the day of admission as their initial symptom; of these, 42.9% (3/7) described OD as the only symptom. All patients in the study received combined treatment with traditional Chinese medicine and Western medicine, and 72.7% (8/11) had partially or fully recovered at discharge. In terms of OD recovery at the 12-month follow-up, 45.5% (5/11) reported at least one sequela, 81.8% (9/11) had recovered completely, 18.2% (2/11) had recovered partially, and there were no recurrent cases.

CONCLUSIONS

Our data revealed that OD frequently presented as the initial or even the only symptom among imported cases. Most OD improvements occurred in the first 2 weeks after onset, and patients with COVID-19 and OD had favorable treatment outcomes during long-term follow-up. A better understanding of the pathogenesis and appropriate treatment of OD is needed to guide clinicians in the care of these patients.

[Neuropsychiatric Aspects of COVID-19 - A Narrative Overview]

The SARS-CoV-2 virus (Severe Acute Respiratory Syndrome Coronavirus Type 2) and COVID-19 (Coronavirus Disease 2019) can affect numerous organ systems. In the present paper we offer an overview of the current state of knowledge about the psychiatric aspects of SARS-CoV-2 infection.Medline, Embase und LIVIVO were searched for relevant literature, the last query dating from March 2nd, 2021. Different stress factors in the context of the pandemic can lead to manifest mental illnesses. In addition, there is a risk of neuropsychological changes due to the biological effects of the virus itself.Our work describes the psychological symptoms of COVID-19 sufferers themselves and the psychological effects of the epidemic and the associated socio-economic and psychosocial stress factors on those who are not sick.The most common psychiatric complication among people with COVID-19 is delirium, while hospitalized patients seem to have an increased incidence of symptoms of anxiety, depression and PTSD. There are many case reports on psychotic disorders. In general, an existing psychiatric illness (especially dementia and psychotic disorders) also increases the risk of infection and of a more severe course of the disease. After recovery from COVID-19 infection, there is also a higher incidence of mental illnesses, in particular "Chronic Post-SARS Syndrome" with its manifestations such as fatigue, anxiety, depression and PTSD. In addition, the course of dementia seems to be negatively influenced by an infection with SARS-CoV-2.The second part deals with the effects of the epidemic as a stressor and the established socio-political measures on the mental health of people with and without previous mental illnesses. The literature currently available shows high symptom values for anxiety and depressive disorders as well as post-traumatic stress disorders, stress, suicidality, sleep disorders etc. Risk factors seem to include female gender, younger age and fewer resources, as well as previous psychiatric or physical illnesses. Extrinsic factors such as high infection rates, large numbers of deaths, long curfews/lockdowns, low trust in the government and ineffective measures against economic and social consequences increase the burden.

Unique Imaging Findings of Neurologic Phantosmia Following Pfizer-BioNtech COVID-19 Vaccination: A Case Report

ABSTRACT

Olfactory dysfunction related to SARS-CoV-2 infection and COVID-19 disease is now well established in the literature. In December 2020, the FDA approved the Pfizer-BioNTech and Moderna vaccines for use in preventing COVID-19 in the United States. To the best of our knowledge, this is the first report of a phantosmia post-Pfizer COVID-19 vaccination, with positive magnetic resonance imaging radiographic findings in a patient with documented absence of infection by SARS-CoV-2 virus or concomitant sinonasal disease.

Putative mechanism of neurological damage in COVID-19 infection

The recent pandemic of the coronavirus infectious disease 2019 (COVID-19) has affected around 192 countries, and projections have shown that around 40% to 70% of world population could be infected in the next months. COVID-19 is caused by the virus SARS- CoV-2, it enters the cells through the ACE2 receptor (angiotensin converting enzyme 2). It is well known that SARS-CoV-2 could develop mild, moderate, and severe respiratory symptoms that could lead to death. The virus receptor is expressed in different organs such as the lungs, kidney, intestine, and brain, among others. In the lung could cause pneumonia and severe acute respiratory syndrome (SARS). The brain can be directly affected by cellular damage due to viral invasion, which can lead to an inflammatory response, by the decrease in the enzymatic activity of ACE2 that regulates neuroprotective, neuro-immunomodulatory and neutralizing functions of oxidative stress. Another severe damage is hypoxemia in patients that do not receive adequate respiratory support. The neurological symptoms that the patient presents, will depend on factors that condition the expression of ACE2 in the brain such as age and sex, as well as the mechanism of neuronal invasion, the immune response and the general state of the patient. Clinical and histopathological studies have described neurological alterations in human patients with COVID-19. These conditions could have a possible contribution to the morbidity and mortality caused by this disease and may even represent the onset of neurodegenerative activity in recovered patients.

The recent pandemic of the coronavirus infectious disease 2019 (COVID-19) has affected around 192 countries, and projections have shown that around 40% to 70% of world population could be infected in the next months. COVID-19 is caused by the virus SARS- CoV-2, it enters the cells through the ACE2 receptor (angiotensin converting enzyme 2). It is well known that SARS-CoV-2 could develop mild, moderate, and severe respiratory symptoms that could lead to death. The virus receptor is expressed in different organs such as the lungs, kidney, intestine, and brain, among others. In the lung could cause pneumonia and severe acute respiratory syndrome (SARS). The brain can be directly affected by cellular damage due to viral invasion, which can lead to an inflammatory response, by the decrease in the enzymatic activity of ACE2 that regulates neuroprotective, neuro-immunomodulatory and neutralizing functions of oxidative stress. Another severe damage is hypoxemia in patients that do not receive adequate respiratory support. The neurological symptoms that the patient presents, will depend on factors that condition the expression of ACE2 in the brain such as age and sex, as well as the mechanism of neuronal invasion, the immune response and the general state of the patient. Clinical and histopathological studies have described neurological alterations in human patients with COVID-19. These conditions could have a possible contribution to the morbidity and mortality caused by this disease and may even represent the onset of neurodegenerative activity in recovered patients.

The coronavirus disease 2019: the prevalence, prognosis, and recovery from olfactory dysfunction (OD)

Background

Many patients with coronavirus disease 2019 (COVID-19) complain from olfactory dysfunction (OD).

Aims/objectives: To evaluate the prevalence, prognosis, and recovery from OD in COVID-19 patients.

Material and methods

In this study, patients with COVID-19 symptoms who were referred to six different tertiary referral centres were recruited after positive results for COVID-19. All patients were assessed for a one-month follow-up after the initial diagnosis of COVID-19.

Results

Three hundred and eleven patients with COVID-19 were recruited in the present study. Two hundred and seven patients (66.6%) had a recent history of OD. One hundred and seventy-eight patients had experienced OD as a primary symptom intercurrent to other COVID-19 symptoms or solely. Sixty-nine patients had OD at the time of presentation to referral centres. Headache and nasal obstruction had significant relationships with recovery from OD in this subgroup, and the platelet count was the most important predictor for the recovery from OD.

One hundred seventy-nine (86.4%) patients were nearly or fully recovered from OD approximately a month after the onset of OD.

Conclusion

Headache, nasal obstruction, and platelet count may have specific roles as prognostic factors in the recovery from OD.