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Journal of Neurology Jun 2023Non-visual hallucinations in Parkinson's disease (PD) can be prevalent and distressing. Most existing research has however, focused on visual hallucinations as well as... (Review)
Review
BACKGROUND
Non-visual hallucinations in Parkinson's disease (PD) can be prevalent and distressing. Most existing research has however, focused on visual hallucinations as well as related risk factors. The current study thus conducted a systematic review to collate existing evidence on non-visual hallucinations in PD, focusing on their prevalence, phenomenology, and clinical-cognitive correlates.
METHODS
Ninety-one relevant studies were included from a systematic search across PsycINFO APA, PubMed, and Web of Science, for peer-reviewed publications in the English language, from 1970 to the present. These comprised a mix of case (30 studies; n = 56) and group design (62 studies; n = 7346) studies, divided into three somewhat overlapping collections to address our three research foci.
RESULTS
Prevalence estimates for hallucinations were: auditory 1.5-72.0%, olfactory 1.6-21.0%, somatic-tactile 0.4-22.5%, gustatory 1.0-15.0%, and sensed presence 0.9-73.3%. Phenomenological inquiries revealed descriptions of vivid, consuming events replete with elaborate detail, adversely affecting PD patients in different ways. Overt experiences of multisensory hallucinations were also highly variable (0.4-80%) but exceedingly common, reported by almost half of the 45 included prevalence studies. There was some evidence for modality-specific hallucination predictors, but this was largely tentative, pending robust replication.
CONCLUSIONS
Marked prevalence figures coupled with phenomenological descriptions implicating distress denote that non-visual and multisensory hallucinations in PD are of clinical significance. More direct research and clinical attention need to be devoted to the study and management of such hallucinatory experiences.
Topics: Humans; Parkinson Disease; Hallucinations; Prevalence; Smell; Cross-Sectional Studies
PubMed: 36702960
DOI: 10.1007/s00415-022-11545-6 -
PloS One 2023Research on the long-term impact on COVID-19 in children and young people (CYP) has been published at pace. We aimed to update and refine an earlier systematic review... (Meta-Analysis)
Meta-Analysis
Persistent symptoms are associated with long term effects of COVID-19 among children and young people: Results from a systematic review and meta-analysis of controlled studies.
BACKGROUND
Research on the long-term impact on COVID-19 in children and young people (CYP) has been published at pace. We aimed to update and refine an earlier systematic review and meta-analysis to assess the current evidence for Post-COVID-19 Condition in CYP.
METHODS
Studies from the previous systematic review were combined with studies from a systematic search from July 2021 to November 2022 (registration PROSPERO CRD42021233153). Eligible studies included CYP aged ≤19 years with confirmed or probable SARS-CoV-2 infection and symptoms persisting at least 12 weeks.
FINDINGS
55 studies (n = 1,139,299 participants) were included. Over two-hundred symptoms were associated with Post COVID-19 Condition. Gastrointestinal problems, headaches, cough and fever were among the most prevalent symptoms with rates of 50.2%, 35.6%, 34.7% and 25.8% respectively. Twenty-one symptoms from 11 studies were suitable for meta-analysis. There were significantly higher pooled estimates of proportions of symptoms for altered / loss of smell or taste, dyspnoea, fatigue, and myalgia in CYP with confirmed SARS-CoV-2 infection. Heterogeneity was high suggesting substantial variation amongst the included studies.
CONCLUSIONS
Many CYP continue to experience symptoms after SARS-CoV-2 infection. Efforts to aid early identification and intervention of those most in need is warranted and the consequences of COVID-19 for CYP call for long-term follow-up.
Topics: Child; Humans; Adolescent; COVID-19; SARS-CoV-2; Headache; Research Design; Gastrointestinal Diseases; Post-Acute COVID-19 Syndrome
PubMed: 38153928
DOI: 10.1371/journal.pone.0293600 -
Association of Olfactory Impairment With All-Cause Mortality: A Systematic Review and Meta-analysis.JAMA Otolaryngology-- Head & Neck... May 2022Olfactory impairment is highly prevalent and associated with multiple comorbidities, including neurodegenerative, cardiovascular, nutritional, and immune disorders.... (Meta-Analysis)
Meta-Analysis
IMPORTANCE
Olfactory impairment is highly prevalent and associated with multiple comorbidities, including neurodegenerative, cardiovascular, nutritional, and immune disorders. However, epidemiologic associations between olfactory impairment and mortality are discordant.
OBJECTIVE
To systematically clarify the epidemiologic associations between olfactory impairment and mortality.
DATA SOURCES
The PubMed, Embase, and Cochrane Library databases were searched from inception to August 13, 2021.
STUDY SELECTION
Two blinded reviewers selected observational studies published as full-length, English-language articles in peer-reviewed journals that reported the presence or severity of chronic olfactory impairment, whether objectively measured or self-reported, in association with any mortality estimate, among adults aged 18 years or older.
DATA EXTRACTION AND SYNTHESIS
Two reviewers independently extracted data, evaluated study bias using the Newcastle-Ottawa Scale, and appraised the quality of the evidence using the Grading of Recommendations Assessment, Development and Evaluation framework, following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) and Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines and a PROSPERO-registered protocol. Maximally adjusted estimates were pooled using mixed-effects models, heterogeneity was measured using I2 statistics, sources of heterogeneity were investigated using meta-regression and subgroup meta-analyses, and publication bias was qualitatively and quantitatively assessed.
MAIN OUTCOMES AND MEASURES
Hazard ratios for all-cause mortality.
RESULTS
One retrospective cohort study and 10 prospective cohort studies (with a total of 21 601 participants) from 1088 nonduplicated records were included. Ten studies had a low risk of bias, whereas 1 study had a moderate risk; exclusion of the latter did not alter conclusions. Nine studies were included in the meta-analysis. Olfactory loss was associated with a significantly higher pooled hazard of all-cause mortality (hazard ratio, 1.52; 95% CI, 1.28-1.80; I2 = 82%). Meta-regression sufficiently explained heterogeneity, with longer mean follow-up duration weakening the pooled association, accounting for 91.3% of heterogeneity. Self-reported and objective effect sizes were similar. Associations were robust to trim-and-fill adjustment and the Egger test for publication bias. The overall quality of evidence was moderate.
CONCLUSIONS AND RELEVANCE
The findings of this systematic review and meta-analysis suggest that olfactory impairment is associated with all-cause mortality and may be a marker of general health and biological aging. Further research is required to establish the underlying mechanisms and the scope for interventions.
Topics: Comorbidity; Humans; Olfaction Disorders; Prospective Studies; Retrospective Studies; Risk
PubMed: 35389456
DOI: 10.1001/jamaoto.2022.0263 -
Journal of Indian Prosthodontic Society 2021Oral stereognosis is an important sensation for a human being to percept any type of materials that are introduced in the oral cavity. It is defined as the ability of an... (Review)
Review
AIM
Oral stereognosis is an important sensation for a human being to percept any type of materials that are introduced in the oral cavity. It is defined as the ability of an individual to recognize objects using only tactile sensation without using vision, audition, balance, somatic function, taste, or smell. The primary purpose of this review was to evaluate the effect of complete dentures on oral stereognostic ability in edentulous subjects.
SETTINGS AND DESIGN
Systematic review based on PRISMA guidelines.
MATERIALS AND METHODS
A systematic search of the electronic databases like PubMed and Web of Science was done using keywords - "stereognosis," "oral stereognosis," "complete denture," and "complete edentulism." In addition to this, a manual search of references mentioned in the articles and gray literature was done. Data extraction and assessment were done by two independent reviewers.
STATISTICAL ANALYSIS USED
Qualitative analysis.
RESULTS
The literature search yielded a total of 61 articles. Thirteen duplicate articles were removed and 36 articles were rejected after initial screening of titles and abstracts. A total of 12 articles were selected for full text reading and 5 of them were included for qualitative analysis.
CONCLUSION
All the included studies showed complete denture treatment therapy improved stereognostic ability in terms of correct identification of test pieces and time taken to identify the objects. There is also a direct relationship between the adaptability of dentures and stereognostic ability.
Topics: Denture, Complete; Humans; Mouth, Edentulous; Stereognosis; Touch
PubMed: 33938860
DOI: 10.4103/jips.jips_401_20 -
Neuropsychology Review Dec 2023Reports of smell loss following traumatic brain injury (TBI) are a well-documented but understudied phenomenon. Given the broad consequences of olfactory loss, we... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
Reports of smell loss following traumatic brain injury (TBI) are a well-documented but understudied phenomenon. Given the broad consequences of olfactory loss, we characterized psychophysical olfactory dysfunction in individuals with moderate to severe TBI using systematic review and meta-analytic methods.
METHODS
Following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) protocol, five databases (PubMed, EMBASE, Cochrane Library, Web of Science, Scopus) were reviewed for studies investigating olfactory dysfunction in persons with moderate to severe TBI. Of the 5,223 studies reviewed, 19 met our inclusion criteria for the systematic review and 11 met inclusion criteria for meta-analysis. We calculated effect sizes (Hedges' g) to characterize the degree of olfactory dysfunction between patients with moderate to severe TBI and controls.
RESULTS
A total of 951 moderate-severe TBI patients from 19 studies were included in the systematic review, which largely demonstrated poorer olfactory psychophysical performances in this patient population. Meta-analysis demonstrated a large effect size for olfactory dysfunction in moderate-severe TBI relative to healthy controls (g=-2.43, 95%CI: -3.16 < δ<-1.69). The magnitude of the effect was moderated by age and patient sex, with larger effect sizes associated with older age (following exclusion of a pediatric population) and larger compositions of women in the patient group.
CONCLUSION
Moderate to severe TBI is associated with prominent olfactory dysfunction. Significant research gaps remain regarding the mechanism, recovery and natural history of olfactory dysfunction following moderate to severe TBI, which has significant clinical implications for the identification and treatment for those with post-traumatic olfactory dysfunction.
Topics: Humans; Child; Female; Olfaction Disorders; Brain Injuries, Traumatic; Smell
PubMed: 36070126
DOI: 10.1007/s11065-022-09563-2 -
Metabolites Dec 2023Obesity, linked to chronic diseases, poses a global health challenge. While the role of the olfactory system in energy homeostasis is well-documented in rodents, its... (Review)
Review
Obesity, linked to chronic diseases, poses a global health challenge. While the role of the olfactory system in energy homeostasis is well-documented in rodents, its role in metabolism regulation and obesity in humans remains understudied. This review examines the interplay between olfactory function and metabolic alterations in human obesity and the effects of bariatric surgery on olfactory capabilities in humans. Adhering to PRISMA guidelines, a systematic review and meta-analysis was conducted, focusing exclusively on original human studies. From 51 articles, 14 were selected for the meta-analysis. It was found that variations in olfactory receptor genes influence the susceptibility to odors and predisposition to weight gain and poor eating habits. Bariatric surgery, particularly sleeve gastrectomy, shows significant improvements in olfactory function (SMD 2.37, 95% CI [0.96, 3.77], I = 92%, = 0.001), especially regarding the olfactory threshold (SMD -1.65, 95% CI [-3.03, -0.27], I = 81%, = 0.02). There is a bidirectional relationship between olfactory function and metabolism in humans. Bariatric surgery improves olfactory perception in obese patients, but it is still unclear if impacting the olfactory system directly affects eating behavior and the energy balance. However, these findings open novel avenues for future studies addressing the olfactory system as a novel target to alter systemic metabolism in humans.
PubMed: 38248819
DOI: 10.3390/metabo14010016 -
Asian Pacific Journal of Allergy and... Sep 2020Olfactory and gustatory dysfunctions (OGD) are pathognomonic symptoms in patients with Coronavirus Disease 2019 (COVID-19). This study reviews the associations of OGD... (Meta-Analysis)
Meta-Analysis
Olfactory and gustatory dysfunctions (OGD) are pathognomonic symptoms in patients with Coronavirus Disease 2019 (COVID-19). This study reviews the associations of OGD with COVID-19 which will be useful for early diagnosis and self-isolation. Systematic searches of PubMed, Ovid Medline, Scopus, and EMBASE electronic databases were performed. Studies reporting OGD in COVID-19 patients were included. Data were pooled for meta-analysis. The outcomes were odds ratios (OR) of OGD in COVID-19 patients. Proportions of smell and/or taste dysfunctions in the COVID-19 patients were assessed. Fourteen studies (21,515 participants, age 49.12 years, 26% male) were included. The OR of olfactory and/or gustatory dysfunctions in COVID-19 patients were 11.26 (95% confidence interval (CI) 5.41 to 23.4) when compared with acute respiratory infection (ARI) without detectable virus and 6.46 (95% CI 2.79 to 14.97) in patients with other respiratory viruses. The OR of olfactory dysfunction in COVID-19 patients were 11.67 (95% CI 6.43 to 21.17) when compared with the ARI patients without detectable virus and 4.17 (95% CI 1.34 to 12.98) with other respiratory viruses. The OR of gustatory dysfunction in COVID-19 patients were 12.70 (95% CI 7.9 to 20.44) when compared with the ARI patients without detectable virus and 4.94 (95%CI 1.59 to 15.31) with other respiratory viruses. Fifty percent (95% CI 36.7 to 63.3%) of COVID-19 patients had olfactory and/or gustatory dysfunctions. In summary, there are associations between OGD and COVID-19 patients. Patients presenting with ARI should be assessed for olfactory and gustatory functions.
Topics: Adult; Betacoronavirus; COVID-19; Coronavirus Infections; Female; Host-Pathogen Interactions; Humans; Male; Middle Aged; Olfaction Disorders; Pandemics; Pneumonia, Viral; Prognosis; Risk Factors; SARS-CoV-2; Smell; Taste; Taste Disorders
PubMed: 32563232
DOI: 10.12932/AP-210520-0853 -
The Cochrane Database of Systematic... Sep 2022Loss of olfactory function is well recognised as a symptom of COVID-19 infection, and the pandemic has resulted in a large number of individuals with abnormalities in... (Review)
Review
BACKGROUND
Loss of olfactory function is well recognised as a symptom of COVID-19 infection, and the pandemic has resulted in a large number of individuals with abnormalities in their sense of smell. For many, the condition is temporary and resolves within two to four weeks. However, in a significant minority the symptoms persist. At present, it is not known whether early intervention with any form of treatment (such as medication or olfactory training) can promote recovery and prevent persisting olfactory disturbance. This is an update of the 2021 review with four studies added.
OBJECTIVES
1) To evaluate the benefits and harms of any intervention versus no treatment for people with acute olfactory dysfunction due to COVID-19 infection. 2) To keep the evidence up-to-date, using a living systematic review approach. SEARCH METHODS: The Cochrane ENT Information Specialist searched the Cochrane ENT Register; Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE; Ovid Embase; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the latest search was 20 October 2021.
SELECTION CRITERIA
We included randomised controlled trials (RCTs) in people with COVID-19 related olfactory disturbance, which had been present for less than four weeks. We included any intervention compared to no treatment or placebo. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were the presence of normal olfactory function, serious adverse effects and change in sense of smell. Secondary outcomes were the prevalence of parosmia, change in sense of taste, disease-related quality of life and other adverse effects (including nosebleeds/bloody discharge). We used GRADE to assess the certainty of the evidence for each outcome. MAIN RESULTS: We included five studies with 691 participants. The studies evaluated the following interventions: intranasal corticosteroid sprays, intranasal corticosteroid drops, intranasal hypertonic saline and zinc sulphate. Intranasal corticosteroid spray compared to no intervention/placebo We included three studies with 288 participants who had olfactory dysfunction for less than four weeks following COVID-19. Presence of normal olfactory function The evidence is very uncertain about the effect of intranasal corticosteroid spray on both self-rated recovery of olfactory function and recovery of olfactory function using psychophysical tests at up to four weeks follow-up (self-rated: risk ratio (RR) 1.19, 95% confidence interval (CI) 0.85 to 1.68; 1 study; 100 participants; psychophysical testing: RR 2.3, 95% CI 1.16 to 4.63; 1 study; 77 participants; very low-certainty evidence). Change in sense of smell The evidence is also very uncertain about the effect of intranasal corticosteroid spray on self-rated change in the sense of smell (at less than 4 weeks: mean difference (MD) 0.5 points lower, 95% CI 1.38 lower to 0.38 higher; 1 study; 77 participants; at > 4 weeks to 3 months: MD 2.4 points higher, 95% CI 1.32 higher to 3.48 higher; 1 study; 100 participants; very low-certainty evidence, rated on a scale of 1 to 10, higher scores mean better olfactory function). Intranasal corticosteroids may make little or no difference to the change in sense of smell when assessed with psychophysical testing (MD 0.2 points, 95% CI 2.06 points lower to 2.06 points higher; 1 study; 77 participants; low-certainty evidence, 0- to 24-point scale, higher scores mean better olfactory function). Serious adverse effects The authors of one study reported no adverse effects, but their intention to collect these data was not pre-specified so we are uncertain if these were systematically sought and identified. The remaining two studies did not report on adverse effects. Intranasal corticosteroid drops compared to no intervention/placebo We included one study with 248 participants who had olfactory dysfunction for ≤ 15 days following COVID-19. Presence of normal olfactory function Intranasal corticosteroid drops may make little or no difference to self-rated recovery at > 4 weeks to 3 months (RR 1.00, 95% CI 0.89 to 1.11; 1 study; 248 participants; low-certainty evidence). No other outcomes were assessed by this study. Data on the use of hypertonic saline nasal irrigation and the use of zinc sulphate to prevent persistent olfactory dysfunction are included in the full text of the review.
AUTHORS' CONCLUSIONS
There is very limited evidence available on the efficacy and harms of treatments for preventing persistent olfactory dysfunction following COVID-19 infection. However, we have identified a number of ongoing trials in this area. As this is a living systematic review we will update the data regularly, as new results become available.
Topics: Adrenal Cortex Hormones; COVID-19; Chronic Disease; Humans; Olfaction Disorders; Randomized Controlled Trials as Topic; Rhinitis; Smell; Zinc Sulfate
PubMed: 36063364
DOI: 10.1002/14651858.CD013877.pub3 -
Journal of Pain and Symptom Management Dec 2012Taste alterations (TAs) and smell alterations (SAs) are frequently observed, yet understudied side effects in chemotherapy patients, considerably affecting patients'... (Meta-Analysis)
Meta-Analysis Review
CONTEXT
Taste alterations (TAs) and smell alterations (SAs) are frequently observed, yet understudied side effects in chemotherapy patients, considerably affecting patients' quality of life.
OBJECTIVES
This review provides a systematic evaluation of the literature on TAs and SAs in cancer chemotherapy patients and discloses understudied research questions.
METHODS
A systematic methodology based on the PRISMA guidelines was applied to identify original research articles with TAs and SAs as primary outcomes in chemotherapy patients. MEDLINE and Embase were searched using Medical Subject Heading and free-text terms. Study extraction and evaluation were done by three reviewers using predefined criteria.
RESULTS
The search revealed 22 eligible studies, including three randomized controlled trials. Different measurement approaches were identified, with a clear trend toward self-report measures during the past decade. The methodological quality of the included studies varied, especially reports on SAs, which were inconsistent and hard to interpret. Regarding TAs, there is evidence that taste thresholds increase during chemotherapy. Qualitative changes, for example, metallic taste, are frequent but cannot be attributed to specific chemotherapy regimens. There are large research gaps regarding TAs and SAs in different patient populations and the impact of different chemotherapy regimens. Adequate management strategies are rare.
CONCLUSION
Current research results do not allow firm conclusions concerning the occurrence, severity, and quality of TAs and SAs under different chemotherapy regimens. Patient information on TAs and SAs, therefore, largely is based on the clinician's experience. In the palliative care setting, TAs and SAs need further investigation in the light of their importance in preventing food-related problems and maintaining a reasonable quality of life.
Topics: Comorbidity; Drug Therapy; Humans; Neoplasms; Olfaction Disorders; Prevalence; Taste Disorders
PubMed: 22921177
DOI: 10.1016/j.jpainsymman.2011.11.011 -
International Forum of Allergy &... Jul 2021Posttraumatic olfactory dysfunction is a clinical challenge due to refractory characteristics and limited therapeutic options. Olfactory training has been proved to be... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Posttraumatic olfactory dysfunction is a clinical challenge due to refractory characteristics and limited therapeutic options. Olfactory training has been proved to be effective for olfactory dysfunction with varied etiologies. We pooled existing studies to evaluate the effects of olfactory training in patients with posttraumatic olfactory dysfunction.
METHODS
A systematic literature review using PubMed, Embase, Cochrane Library, and Web of Science was conducted to identify studies assessing olfactory change in patients with posttraumatic olfactory dysfunction after olfactory training.
RESULTS
Of the initial 812 abstracts reviewed, 13 full-text articles were included. Clinically significant results after olfactory training were defined as an improvement of threshold, discrimination, and identification (TDI) score ≥6 or University of Pennsylvania Smell Identification Test (UPSIT) score ≥4. Six studies were included in the meta-analysis, 36.31% (95% confidence interval [CI], 0.28 to 0.45) of posttraumatic patients would achieve clinically significant results after olfactory training with a mean increase of TDI score of 4.61.
CONCLUSION
Olfactory training might be a promising modality for the treatment of posttraumatic olfactory dysfunction. More high-quality studies with controls are needed to clarify the effect of olfactory training on total olfactory performance and subcomponents of olfaction.
Topics: Humans; Olfaction Disorders; Smell
PubMed: 33486898
DOI: 10.1002/alr.22758