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Cells Jan 2023The omicron variant is thought to cause less olfactory dysfunction than previous variants of SARS-CoV-2, but the reported prevalence differs greatly between populations... (Meta-Analysis)
Meta-Analysis Review
The omicron variant is thought to cause less olfactory dysfunction than previous variants of SARS-CoV-2, but the reported prevalence differs greatly between populations and studies. Our systematic review and meta-analysis provide information regarding regional differences in prevalence as well as an estimate of the global prevalence of olfactory dysfunction based on 62 studies reporting information on 626,035 patients infected with the omicron variant. Our estimate of the omicron-induced prevalence of olfactory dysfunction in populations of European ancestry is 11.7%, while it is significantly lower in all other populations, ranging between 1.9% and 4.9%. When ethnic differences and population sizes are considered, the global prevalence of omicron-induced olfactory dysfunction in adults is estimated to be 3.7%. Omicron's effect on olfaction is twofold to tenfold lower than that of the alpha or delta variants according to previous meta-analyses and our analysis of studies that directly compared the prevalence of olfactory dysfunction between omicron and previous variants. The profile of the prevalence differences between ethnicities mirrors the results of a recent genome-wide association study that connected a gene locus encoding an odorant-metabolizing enzyme, UDP glycosyltransferase, to the extent of COVID-19-related loss of smell. Our analysis is consistent with the hypothesis that this enzyme contributes to the observed population differences.
Topics: Adult; Humans; SARS-CoV-2; Smell; COVID-19; Genome-Wide Association Study; Prevalence; Olfaction Disorders
PubMed: 36766771
DOI: 10.3390/cells12030430 -
Neuropsychology Review Mar 2024Olfactory training (OT), or smell training,consists of repeated exposure to odorants over time with the intended neuroplastic effect of improving or remediating... (Review)
Review
Olfactory training (OT), or smell training,consists of repeated exposure to odorants over time with the intended neuroplastic effect of improving or remediating olfactory functioning. Declines in olfaction parallel declines in cognition in various pathological conditions and aging. Research suggests a dynamic neural connection exists between olfaction and cognition. Thus, if OT can improve olfaction, could OT also improve cognition and support brain function? To answer this question, we conducted a systematic review of the literature to determine whether there is evidence that OT translates to improved cognition or altered brain morphology and connectivity that supports cognition. Across three databases (MEDLINE, Scopus, & Embase), 18 articles were identified in this systematic review. Overall, the reviewed studies provided emerging evidence that OT is associated with improved global cognition, and in particular, verbal fluency and verbal learning/memory. OT is also associated with increases in the volume/size of olfactory-related brain regions, including the olfactory bulb and hippocampus, and altered functional connectivity. Interestingly, these positive effects were not limited to patients with smell loss (i.e., hyposmia & anosmia) but normosmic (i.e., normal ability to smell) participants benefitted as well. Implications for practice and research are provided.
Topics: Humans; Brain; Cognition; Olfaction Disorders; Olfactory Training; Smell
PubMed: 36725781
DOI: 10.1007/s11065-022-09573-0 -
European Journal of Neurology May 2023Acute health events, including infections, can trigger the onset of functional neurological disorder (FND). It was hypothesized that a proportion of people with long... (Review)
Review
BACKGROUND AND PURPOSE
Acute health events, including infections, can trigger the onset of functional neurological disorder (FND). It was hypothesized that a proportion of people with long COVID might be experiencing functional symptoms.
METHODS
A systematic review of studies containing original data on long COVID was performed. The frequency and characteristics of neurological symptoms were reviewed, looking for positive evidence suggesting an underlying functional disorder and the hypothesized causes of long COVID.
RESULTS
In all, 102 studies were included in our narrative synthesis. The most consistently reported neurological symptoms were cognitive difficulties, headaches, pain, dizziness, fatigue, sleep-related symptoms and ageusia/anosmia. Overall, no evidence was found that any authors had systematically looked for positive features of FND. An exception was three studies describing temporal inconsistency. In general, the neurological symptoms were insufficiently characterized to support or refute a diagnosis of FND. Moreover, only 13 studies specifically focused on long COVID after mild infection, where the impact of confounders from the general effects of severe illness would be mitigated. Only one study hypothesized that some people with long COVID might have a functional disorder, and another eight studies a chronic-fatigue-syndrome-like response.
DISCUSSION
Neurological symptoms are prevalent in long COVID, but poorly characterized. The similarities between some manifestations of long COVID and functional disorders triggered by acute illnesses are striking. Unfortunately, the current literature is plagued by confounders, including the mixing of patients with initial mild infection with those with severe acute medical complications. The hypothesis that long COVID might in part correspond to a functional disorder remains untested.
Topics: Humans; Post-Acute COVID-19 Syndrome; COVID-19; Conversion Disorder; Anosmia; Fatigue
PubMed: 36719069
DOI: 10.1111/ene.15721 -
Journal of Clinical Nursing Jan 2024Single studies support the presence of several post-COVID-19 symptoms; however, there is no evidence for the synthesis of symptoms. (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Single studies support the presence of several post-COVID-19 symptoms; however, there is no evidence for the synthesis of symptoms.
OBJECTIVE
We attempt to provide an overview of the persistent symptoms that post-COVID-19 patients encounter, as well as the duration of these symptoms to help them plan their rehabilitation.
DESIGN
Systematic review and meta-analysis.
PARTICIPANTS
A total of 16 studies involving 8756 patients post-COVID-19 were included.
METHODS
The CINAHL, PubMed, EMBASE, Scopus, and Web of Science databases were searched from 2019 to August 2021. Observational studies that reported data on post-COVID-19 symptoms were included. The methodological quality of the studies was assessed using the Joanna Briggs Institute Critical Appraisal for Observational Studies. We included medium- to high-quality studies. We used a random-effects model for the meta-analytical pooled prevalence of each post-COVID-19 symptom, and I statistics for heterogeneity.
RESULTS
From the 2481 studies identified, 16 met the inclusion criteria. The sample included 7623 hospitalised and 1133 non-hospitalised patients. We found the most prevalent symptoms were fatigue and dyspnea with a pooled prevalence ranging from 42% (27%-58%). Other post-COVID-19 symptoms included sleep disturbance 28% (14%-45%), cough 25% (10%-44%), anosmia/ageusia 24% (7%-47%), fever 21% (4%-47%), myalgia 17% (2%-41%), chest pain 11% (5%-20%), and headache 9% (2%-20%). In addition to physical symptoms, anxiety/depression was also prevalent 27% (8%-53%).
CONCLUSIONS
Fatigue and dyspnea were the most prevalent post-COVID-19 symptoms and experienced up to 12 months.
RELEVANCE TO CLINICAL PRACTICE
Multiple persistent symptoms are still experienced until 12 months of post-Covid 19. This meta-analysis should provide some awareness to nurses to highlights the unmet healthcare needs of post-COVID-19 patients. Long-term monitoring for the evaluation and treatment of symptoms and conditions and rehabilitation programs should be conducted.
Topics: Humans; COVID-19; Chest Pain; Cough; Dyspnea; Fatigue
PubMed: 36426658
DOI: 10.1111/jocn.16471 -
International Journal of... 2022With the global epidemic of coronavirus disease 2019 (COVID-19), vaccination rates are increasing globally. This study evaluated the relevant clinical manifestations of... (Meta-Analysis)
Meta-Analysis
OBJECTIVE
With the global epidemic of coronavirus disease 2019 (COVID-19), vaccination rates are increasing globally. This study evaluated the relevant clinical manifestations of vaccinated COVID-19 patients.
METHODS
We searched carefully in 11 databases such as PubMed, Embase, Scopus, Cochrane Library, Web of Science, Ovid, China National Knowledge Infrastructure Database, Wan Fang Data, Sinomed, VIP Database, and Reading Showing Database up to 26 March 2022. To search for articles that have described the characteristics of vaccinated patients including epidemiological and clinical symptoms. Statistical analysis of the extracted data using STATA 14.0.
RESULTS
A total of 58 articles and 263,708 laboratory-confirmed COVID-19 patients were included. Most of the patients in the vaccinated group had more asymptomatic infection and fewer severe illnesses. There were significant differences in ethnicity, and strain infected with COVID-19, and comorbidities (hyperlipidemia, diabetes, obesity, kidney disease, immunocompromised, cardiovascular disease, and tumor) and symptoms (fever, cough, gastrointestinal symptoms, neurological symptoms, and dysgeusia/anosmia) between vaccinated group and unvaccinated group. Oxygen support, use of steroid, days in hospital, hospital treatment, ICU treatment, death, and poor prognosis were also significantly different.
CONCLUSION
Compared with the vaccinated group, patients in the unvaccinated group had a more severe clinical manifestations. Vaccines are also protective for infected people.
Topics: Humans; Cardiovascular Diseases; China; COVID-19; Neoplasms; Research Design
PubMed: 36412572
DOI: 10.1177/03946320221141802 -
Primary Health Care Research &... Nov 2022It is unclear, whether the initial disease severity may help to predict which COVID-19 patients at risk of developing persistent symptoms. (Meta-Analysis)
Meta-Analysis
BACKGROUND
It is unclear, whether the initial disease severity may help to predict which COVID-19 patients at risk of developing persistent symptoms.
AIM
The aim of this study was to examine whether the initial disease severity affects the risk of persistent symptoms in post-acute COVID-19 syndrome and long COVID.
METHODS
A systematic search was conducted using PUBMED, Google Scholar, EMBASE, and ProQuest databases to identify eligible articles published after January 2020 up to and including 30 August 2021. Pooled odds ratio (OR) and confidence intervals (CIs) were calculated using random effects meta-analysis.
FINDINGS
After searching a total of 7733 articles, 20 relevant observational studies with a total of 7840 patients were selected for meta-analysis. The pooled OR for persistent dyspnea in COVID-19 survivors with a severe versus nonsevere initial disease was 2.17 [95%CI 1.62 to 2.90], and it was 1.33 [95%CI 0.75 to 2.33] for persistent cough, 1.30 [95%CI 1.06 to 1.58] for persistent fatigue, 1.02 [95%CI 0.73 to 1.40] for persistent anosmia, 1.22 [95%CI 0.69 to 2.16] for persistent chest pain, and 1.30 [95%CI 0.93 to 1.81] for persistent palpitation.
CONCLUSIONS
Contrary to expectations, we did not observe an association between the initial COVID-19 disease severity and common persistent symptoms except for dyspnea and fatigue. In addition, it was found that being in the acute or prolonged post-COVID phase did not affect the risk of symptoms. Primary care providers should be alert to potential most prevalent persistent symptoms in all COVID-19 survivors, which are not limited to patients with critical-severe initial disease.
Topics: Humans; COVID-19; SARS-CoV-2; Dyspnea; Fatigue; Severity of Illness Index; Post-Acute COVID-19 Syndrome
PubMed: 36352492
DOI: 10.1017/S1463423622000585 -
The Journal of Laryngology and Otology Sep 2023Smell impairment affects 60-80 per cent of individuals aged over 80 years. This review aimed to identify any association between vitamin D deficiency and smell... (Review)
Review
OBJECTIVE
Smell impairment affects 60-80 per cent of individuals aged over 80 years. This review aimed to identify any association between vitamin D deficiency and smell impairment, and determine the efficacy of vitamin D to treat smell impairment.
METHODS
A literature search was conducted across four databases between the years 2000 and 2022. The literature screen was performed by two independent reviewers.
RESULTS
Seven articles were included in this review. Four studies examined the association between vitamin D deficiency and smell impairment, with three studies identifying a significant relationship. Three studies investigated the use of vitamin D as treatment for smell impairment, which found complete resolution or significant symptom improvement after vitamin D deficiency was treated.
CONCLUSION
This review identified limited studies on this topic. As vitamin D supplementation is relatively cost-efficient, further large-scale studies should be carried out to investigate the efficacy of vitamin D for treating anosmia.
Topics: Humans; Aged, 80 and over; Vitamin D; Smell; Vitamins; Vitamin D Deficiency; Olfaction Disorders
PubMed: 36341550
DOI: 10.1017/S0022215122002389 -
Cureus Sep 2022Few studies have thoroughly evaluated the neuro-invasive effect of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, which may contribute to a... (Review)
Review
Few studies have thoroughly evaluated the neuro-invasive effect of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, which may contribute to a wide range of sequelae from mild long-term effects like headaches and fatigue to severe events like stroke and arrhythmias. Our study aimed to evaluate the long-term neurological effects of coronavirus disease 2019 (COVID-19) among patients discharged from the hospital. In this systematic review and meta-analysis, we assessed the long-term neurocognitive effects of COVID-19. Post-COVID-19 neurological sequelae were defined as persistent symptoms of headache, fatigue, myalgia, anosmia, dysgeusia, sleep disturbance, issues with concentration, post-traumatic stress disorder (PTSD), suicidality, and depression long after the acute phase of COVID-19. Data from observational studies describing post-COVID-19 neurocognitive sequelae and severity of COVID-19 from September 1, 2019, to the present were extracted following the Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol with a consensus of three independent reviewers. A systematic review was performed for qualitative evaluation and a meta-analysis was performed for quantitative analysis by calculating log odds of COVID-19 neurocognitive sequelae. The odds ratio (OR) and 95% confidence interval (CI) were obtained and forest plots were created using random effects models. We found seven studies, out of which three were used for quantitative synthesis of evidence. Of the 3,304 post-COVID-19 patients identified, 50.27% were male with a mean age of 56 years; 20.20% had post-COVID-19 symptoms more than two weeks after the acute phase of infection. Among persistence symptoms, neurocognitive symptoms like headache (27.8%), fatigue (26.7%), myalgia (23.14%), anosmia (22.8%), dysgeusia (12.1%), sleep disturbance (63.1%), confusion (32.6%), difficulty to concentrate (22%), and psychiatric symptoms like PTSD (31%), feeling depressed (20%), and suicidality (2%) had a higher prevalence. In meta-analysis, COVID-19 patients with severe symptoms had higher odds of headache (pooled OR: 4.53; 95% CI: 2.37-8.65; p<0.00001; I: 0%) and myalgia (pooled OR: 3.36; 95% CI: 2.71-4.17; p<0.00001; I: 0%). Anosmia, fatigue, and dysgeusia had higher but non-significant odds following COVID-19. Although we had sufficient data for headache and fatigue to identify higher rates and associations following COVID-19, we could not establish relationships with other post-COVID-19 neurocognitive séqueles. Long-term follow-up may mitigate the neurocognitive effects among COVID-19 patients as these symptoms are also associated with a poor quality of life.
PubMed: 36321004
DOI: 10.7759/cureus.29694 -
The Journal of Venomous Animals and... 2022Peripheral facial paralysis (PFP) has been shown to be a neurological manifestation of COVID-19. The current study presents two cases of PFP after COVID-19, along with a... (Review)
Review
Peripheral facial paralysis (PFP) has been shown to be a neurological manifestation of COVID-19. The current study presents two cases of PFP after COVID-19, along with a rapid review of known cases in the literature. Both case reports were conducted following CARE guidelines. We also performed a systematic review of PFP cases temporally related to COVID-19 using PubMed, Embase, and Cochrane Library databases on August 30, 2021, using a rapid review methodology. The two patients experienced PFP 102 and 110 days after COVID-19 symptom onset. SARS-CoV-2 RNA was detected in nasal samples through reverse-transcription real-time polymerase chain reaction (RT-qPCR) testing. Anosmia was the only other neurological manifestation. PFP was treated with steroids in both cases, with complete subsequent recovery. In the rapid review, we identified 764 articles and included 43 studies. From those, 128 patients with PFP were analyzed, of whom 42.1% (54/128) were male, 39.06% (50/128) female, and in 23 cases the gender was not reported. The age range was 18 to 59 (54.68%). The median time between COVID-19 and PFP was three days (ranging from the first symptom of COVID-19 to 40 days after the acute phase of infection). Late PFP associated with COVID-19 presents mild symptoms and improves with time, with no identified predictors. Late PFP should be added to the spectrum of neurological manifestations associated with the long-term effects of SARS-CoV-2 infection as a post COVID-19 condition.
PubMed: 36305011
DOI: 10.1590/1678-9199-JVATITD-2022-0020 -
Inflammopharmacology Dec 2022There is evidence that chemosensory dysfunctions, including smell and taste disorders, are common findings in patients with SARS-CoV-2 infection. However, the underlying... (Meta-Analysis)
Meta-Analysis
BACKGROUND
There is evidence that chemosensory dysfunctions, including smell and taste disorders, are common findings in patients with SARS-CoV-2 infection. However, the underlying biological mechanisms and the role of inflammatory markers are still poorly understood.
AIM
To investigate the inflammatory biomarkers levels in patients with COVID-19 presenting chemosensory dysfunctions.
METHODS
This review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. A systematic literature search was performed from January 1, 2020, to May 12, 2022. Observational studies that provided data on hematological, biochemical, infection-related indices and cellular immunity, and coagulation function in patients with COVID-19 experiencing smell and/or taste disorders were considered eligible. Effect sizes were reported as standardized mean difference (SMD) with 95% confidence intervals (CI). A negative effect size indicated that the inflammatory biomarker levels were lower among patients with chemosensory dysfunctions.
RESULTS
Eleven studies were included. Patients with chemosensory disturbances had lower levels of leukocytes (SMD - 0.18, 95% CI - 0.35 to - 0.01, p = 0.04), lactate dehydrogenase (SMD - 0.45, 95% CI - 0.82 to - 0.09, p = 0.01), IL-6 (SMD - 0.25, 95% CI - 0.44 to - 0.06, p < 0.01), and C-reactive protein (SMD - 0.33, 95% CI - 0.58 to - 0.08, p < 0.01) than patients without chemosensory disturbances.
CONCLUSION
Patients with SARS-CoV-2 infection who have olfactory and gustatory disorders have a lower inflammatory response than patients who do not have chemosensory alterations. The presence of these symptoms may indicate a more favorable clinical course for COVID-19.
Topics: Humans; COVID-19; SARS-CoV-2; Olfaction Disorders; Taste Disorders; Skin Diseases; Biomarkers
PubMed: 36097300
DOI: 10.1007/s10787-022-01066-z