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The Laryngoscope Jun 2022Olfactory dysfunction (OD) is a common presenting symptom of COVID-19 infection. Radiological imaging of the olfactory structures in patients with COVID-19 and OD can... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
Olfactory dysfunction (OD) is a common presenting symptom of COVID-19 infection. Radiological imaging of the olfactory structures in patients with COVID-19 and OD can potentially shed light on its pathogenesis, and guide clinicians in prognostication and intervention.
METHODS
PubMed, Embase, Cochrane, SCOPUS were searched from inception to August 1, 2021. Three reviewers selected observational studies, case series, and case reports reporting radiological changes in the olfactory structures, detected on magnetic resonance imaging, computed tomography, or other imaging modalities, in patients aged ≥18 years with COVID-19 infection and OD, following preferred reporting items for systematic reviews and meta-analyses guidelines and a PROSPERO-registered protocol (CRD42021275211). We described the proportion of radiological outcomes, and used random-effects meta-analyses to pool the prevalence of olfactory cleft opacification, olfactory bulb signal abnormalities, and olfactory mucosa abnormalities in patients with and without COVID-19-associated OD.
RESULTS
We included 7 case-control studies (N = 353), 11 case series (N = 154), and 12 case reports (N = 12). The pooled prevalence of olfactory cleft opacification in patients with COVID-19 infection and OD (63%, 95% CI = 0.38-0.82) was significantly higher than that in controls (4%, 95% CI = 0.01-0.13). Conversely, similar proportions of cases and controls demonstrated olfactory bulb signal abnormalities (88% and 94%) and olfactory mucosa abnormalities (2% and 0%). Descriptive analysis found that 55.6% and 43.5% of patients with COVID-19 infection and OD had morphological abnormalities of the olfactory bulb and olfactory nerve, respectively, while 60.0% had abnormal olfactory bulb volumes.
CONCLUSION
Our findings implicate a conductive mechanism of OD, localized to the olfactory cleft, in approximately half of the affected COVID-19 patients. Laryngoscope, 132:1260-1274, 2022.
Topics: Adolescent; Adult; COVID-19; Humans; Olfaction Disorders; Olfactory Bulb; Olfactory Mucosa; Smell
PubMed: 35318656
DOI: 10.1002/lary.30078 -
Respiratory Physiology & Neurobiology May 2023The perception of breathlessness is mechanistically linked to the awareness of increased inspiratory neural drive (IND). Stimulation of upper airway cold receptors on... (Review)
Review
The perception of breathlessness is mechanistically linked to the awareness of increased inspiratory neural drive (IND). Stimulation of upper airway cold receptors on the trigeminal nerve (TGN) with TGN agonists such as menthol or cool air to the face/nose has been hypothesized to reduce breathlessness by decreasing IND. The aim of this systematic scoping review was to identify and summarize the results of studies in animals and humans reporting on the impact of TGN stimulation or blockade on measures of IND. Thirty-one studies were identified, including 19 in laboratory animals and 12 in human participants. Studies in laboratory animals consistently reported that as TGN activity increased, measures of IND decreased (e.g., phrenic nerve activity). In humans, stimulation of the TGN with a stream of cool air to the face/nose decreased the sensitivity of the ventilatory chemoreflex response to hypercapnia. Otherwise, TGN stimulation with menthol or cool air to the face/note had no effect on measures of IND in humans. This review provides new insight into a potential neural mechanism of breathlessness relief with selected TGN agonists.
Topics: Animals; Humans; Menthol; Olfactory Nerve; Dyspnea; Nose; Trigeminal Nerve
PubMed: 36792044
DOI: 10.1016/j.resp.2023.104035 -
Therapeutic Advances in Chronic Disease 2023Complementary and alternative medicine (CAM) interventions are growing in popularity as possible treatments for long COVID symptoms. However, comprehensive analysis of... (Review)
Review
BACKGROUND
Complementary and alternative medicine (CAM) interventions are growing in popularity as possible treatments for long COVID symptoms. However, comprehensive analysis of current evidence in this setting is still lacking.
OBJECTIVE
This study aims to review existing published studies on the use of CAM interventions for patients experiencing long COVID through a systematic review.
DESIGN
Systematic review of randomized controlled trials (RCTs).
METHODS
A comprehensive electronic literature search was performed in multiple databases and clinical trial registries from September 2019 to January 2023. RCTs evaluating efficacy and safety of CAM for long COVID were included. Methodological quality of each included trial was appraised with the Cochrane 'risk of bias' tool. A qualitative analysis was conducted due to heterogeneity of included studies.
RESULTS
A total of 14 RCTs with 1195 participants were included in this review. Study findings demonstrated that CAM interventions could benefit patients with long COVID, especially those suffering from neuropsychiatric disorders, olfactory dysfunction, cognitive impairment, fatigue, breathlessness, and mild-to-moderate lung fibrosis. The main interventions reported were self-administered transcutaneous auricular vagus nerve stimulation, neuro-meditation, dietary supplements, olfactory training, aromatherapy, inspiratory muscle training, concurrent training, and an online breathing and well-being program.
CONCLUSION
CAM interventions may be effective, safe, and acceptable to patients with symptoms of long COVID. However, the findings from this systematic review should be interpreted with caution due to various methodological limitations. More rigorous trials focused on CAM for long COVID are warranted in the future.
PubMed: 37841213
DOI: 10.1177/20406223231204727 -
Acta Oto-laryngologica Jun 2012The sense of smell provides people with valuable input from the chemical environment around them. The human sense of smell generally fails in three ways; one is an... (Review)
Review
The sense of smell provides people with valuable input from the chemical environment around them. The human sense of smell generally fails in three ways; one is an intensity reduction and the other two are the quality of changes. Smell disorders can be classified into central or peripheral depending on their origin. Central causes can be related to an area of hyper-functioning brain cells generating this odor perception, thus olfactory distortions have also been observed with epilepsy and migraine. In this paper, we present a review of the current clinical understanding of olfactory distortions and discuss how they can be evaluated and therapies to treat this debilitating condition.
Topics: Diagnosis, Differential; Diagnostic Imaging; Humans; Olfaction Disorders; Olfactory Nerve Diseases; Smell
PubMed: 22582778
DOI: 10.3109/00016489.2012.659759 -
Laryngoscope Investigative... Oct 2019Evidence suggests that olfactory impairment (OI) may be a degenerative neurologic complication of diabetes; however, the association is not yet well established. The...
BACKGROUND
Evidence suggests that olfactory impairment (OI) may be a degenerative neurologic complication of diabetes; however, the association is not yet well established. The objective of this work was to systematically review existing literature on the association between diabetes and OI in adults, with meta-analysis of evaluable studies.
METHODS
A literature search encompassing 358 abstracts from the last 75 years in PubMed, EMBASE, and Cochrane was performed. English-language articles investigating adults with diabetes and OI in comparison to control groups with original data and ≥7 subjects were included. The Newcastle-Ottawa scale was applied for quality assessment. Two investigators independently reviewed all articles. For meta-analysis, the odds ratio of OI in diabetes compared with control groups was calculated using the fixed effects model.
RESULTS
The initial search yielded 358 abstracts, from which 21 articles were reviewed and 11 articles (n = 6,747) were included. Studies included were case-control (64%) or cross-sectional (36%) with evidence level 3b. On the Newcastle-Ottawa scale, the mean quality assessment score for case-control and cross-sectional studies was 7.4 (maximum of 9) and 7.0 (maximum of 10), respectively. A statistically significant association between diabetes and olfaction compared with controls was found in 6 (55%) of the 11 articles. Four studies were eligible for meta-analysis, which yielded an overall odds of having OI with diabetes as 1.58 times more likely than in control groups (95% CI [1.16, 2.16]; = 10.3%).
CONCLUSIONS
The reviewed studies support a significant association between diabetes and OI. Further studies are warranted to characterize this association.
LEVEL OF EVIDENCE
3a.
PubMed: 31637288
DOI: 10.1002/lio2.291 -
The Journal of Craniofacial Surgery May 2017The aim of this study was to perform a systematic review of the treatment of nasal bone fractures. The search terms ("nasal bone fracture" AND complication) and ("nasal... (Review)
Review
The aim of this study was to perform a systematic review of the treatment of nasal bone fractures. The search terms ("nasal bone fracture" AND complication) and ("nasal bone fracture" AND [anosmia OR olfaction OR olfactory nerve OR smell]) and (anosmia AND ["nasal preparation" OR "nasal antiseptics"]) were used to search PubMed and SCOPUS. Of the 500 titles, 40 full papers were reviewed. One paper was excluded, and 3 mined papers were added. Ultimately, 12 papers were analyzed. The overall deformity rate was 10.4% ± 4.8%. No significant differences were found between patients who underwent closed reduction (14.7% ± 7.3%) and those who underwent open reduction (9.4% ± 4.4%), between those who underwent local anesthesia (5.8% ± 4.5%), and those who underwent general anesthesia (8.8% ± 3.8%), or between those who received timely treatment (5.7%) and those whose treatment was delayed (9.0%). Septal deviation occurred in 10.0% of patients as a sequela of nasal bone fracture. The nasal obstruction rate was 10.5% ± 5.3%. Fewer patients of nasal obstruction occurred in the open reduction patients (6.9% ± 4.4%) than in the closed reduction patients (15.2%). One patient of epiphora and 1 patient of diplopia were reportedAmong the 77 patients with nasal bone fractures, 29 (37.7% ± 11.3%) complained of olfactory disturbances. No significant associations were found between the type of fracture and the presence of olfactory disturbances. It is recommended for providers to explain to patients that approximately one-tenth of nasal bone fractures exhibit deformity, septal deviation, or nasal obstruction after surgery. Surgeons should take considerable care to avoid the olfactory mucosa during reduction surgery.
Topics: Humans; Nasal Bone; Nasal Obstruction; Nose Deformities, Acquired; Olfaction Disorders; Open Fracture Reduction; Skull Fractures; Tomography, X-Ray Computed
PubMed: 28468171
DOI: 10.1097/SCS.0000000000003482 -
Cureus Nov 2022The COVID-19 pandemic has created huge economic and healthcare burdens. In most cases, the virus affects the lungs and causes respiratory symptoms. Additionally, its... (Review)
Review
The COVID-19 pandemic has created huge economic and healthcare burdens. In most cases, the virus affects the lungs and causes respiratory symptoms. Additionally, its impact on the cranial nerves remains unclear. We thus aimed to investigate cranial nerve dysfunction in patients with COVID-19 infection. We conducted a systematic literature search of relevant and eligible literature in five databases: PubMed, Web of Science, Medline, EBSCO, and Google Scholar. Our sample included 21 case reports, one case series with 29 patients, and one analytical study with 135 cases. Participant ages ranged from 23 months to 72 years (mean age of 47.5 ± 19.02). The mean time from respiratory symptoms to the onset of neurological signs was (9.6 ± 7.4) days, and the mean recovery time was (16.3 ± 15.3) days. Cranial nerve impairment associated with COVID-19 infection has affected a large population, from infants to the elderly. Facial and abducent nerves were the most commonly affected cranial nerves with reported good prognosis or complete recovery within a few days to weeks. Olfactory dysfunctions were widely detected among COVID-19 patients.
PubMed: 36589199
DOI: 10.7759/cureus.31997 -
European Spine Journal : Official... May 2015The debate on the effects and outcome of olfactory ensheathing cell (OEC) transplantation for the treatment of spinal cord injury (SCI) has remained unresolved for... (Meta-Analysis)
Meta-Analysis Review
PURPOSE
The debate on the effects and outcome of olfactory ensheathing cell (OEC) transplantation for the treatment of spinal cord injury (SCI) has remained unresolved for nearly 20 years. This study aimed to evaluate the safety and efficacy of OEC transplantation in chronic SCI patients.
METHOD
Electronic databases, including PubMed, the Cochrane Library, EMBASE, and MEDLINE, were searched to identify clinical therapeutic trials studying the use of OEC transplantation for SCI in humans. Each trial was analyzed in accordance with the criteria of the Cochrane Handbook 5.1.0 and MOOSE. Data were analyzed with Review Manager 5.2 and Meta-Analyst Beta 3.13 software.
RESULTS
Eleven articles concerning 10 studies of 1,193 patients with chronic SCI treated with OEC transplantation were selected for review. All the articles had low methodological quality. Studies reported their outcomes using the American Spinal Injury Association (ASIA) Impairment Scale; the AISA motor, light touch, pinprick score; the Functional Independence Measure and (or) other measure methods. According to the available relevant data, the incidences of total adverse events and mortality were 7.68% (n = 742) and 0.35% (n = 566), respectively. The most frequently reported adverse events were fever, mild anemia, and syringomyelia; however, the statistical adverse events occurring in different studies were cerebrospinal fluid leakage (7.00%, n = 586, 2 trials), sensory deterioration (0.70%, n = 573, 2 trials), and both motor and sensory deterioration (0.68%, n = 586, 2 trials).
CONCLUSIONS
Given the results from our study, we conclude that OEC transplantation appears to be safe, although the evidence for efficacy is modest and requires the support of prospective, randomized trials in larger cohorts of patients. Further randomized controlled trials utilizing strict therapy programs and implanted cell selections are needed to confirm these findings.
Topics: Cell Transplantation; Chronic Disease; Humans; Nerve Regeneration; Olfactory Mucosa; Prospective Studies; Spinal Cord Injuries
PubMed: 25001890
DOI: 10.1007/s00586-014-3416-6 -
Neurosurgical Review Sep 2023Optic canal unroofing (OCU) has gradually become a routine technique for tuberculum sellae meningiomas (TSMs) resection. This meta-analysis aimed to evaluate the... (Meta-Analysis)
Meta-Analysis Review
Optic canal unroofing (OCU) has gradually become a routine technique for tuberculum sellae meningiomas (TSMs) resection. This meta-analysis aimed to evaluate the efficacy and safety of OCU. A systematic review and meta-analysis of the published literature on this topic from 2003 to 2023 were conducted in accordance with the PRISMA guidelines. Rigorous statistical analysis with a p-value was performed for related change in visual improvement, gross total resection (GTR), visual deterioration, and olfactory nerve damage. The study included 15 articles with 384 patients in whom OCU was performed by the transcranial approach (TCA) or the endoscopic endonasal approach (EEA). Of these, 341 patients had preoperative visual loss, and 266 patients had postoperative visual recovery. The overall rate of visual improvement was 0.803 (95% CI: 0.733-0.874, p < 0.01). The rate of visual improvement in the EEA and TCA groups was 0.884 (95% CI: 0.803-0.965, p < 0.01) and 0.788 (95% CI: 0.700-0.875, p < 0.01). Further analysis of classification shows that the rate of visual improvement in Type I: < 2 cm was 0.889(95% CI: 0.739-0.969), Type II:2-4 cm was 0.844(95% CI: 0.755-0.910), Type III: > 4 cm was 0.500(95% CI: 0.068-0.932) and the total was 0.853(95% CI: 0.779-0.927 p < 0.01) with low heterogeneity of I = 20.80%.Twelve studies separately reported GTR with OCU was 293; the rate of GTR was 0.911 (95% CI: 0.848-0.961, p < 0.01). And the rate of GTR in Type I: < 2 cm was 0.933(95% CI: 0.817-0.986), Type II:2-4 cm was 0.880(95% CI: 0.800-0.936), Type III: > 4 cm was 0.600(95% CI: 0.147-0.947). The total was 0.897(95% CI: 0.830-0.965 p < 0.01) with low heterogeneity of I = 34.57%. The related complications of OCU were visual deterioration and olfactory nerve damage. Visual decline was reported in nine studies, and the rate was 0.077 (95% CI: 0.041-0.113, p < 0.01). Six studies reported olfactory nerve damage, and the overall rate was 0.054 (95% CI: 0.019-0.090, p < 0.01). OCU could significantly recover preoperative impaired vision and make GTR easier to achieve, which was also a safe and effective technique in TSM.
Topics: Humans; Meningioma; Postoperative Period; Skull Base Neoplasms; Meningeal Neoplasms
PubMed: 37698750
DOI: 10.1007/s10143-023-02151-9 -
European Journal of Neurology Oct 2021Mounting evidence supports an association between Guillain-Barré syndrome spectrum (GBSs) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND AND PURPOSE
Mounting evidence supports an association between Guillain-Barré syndrome spectrum (GBSs) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, GBSs in the setting of coronavirus disease 2019 (COVID-19) remains poorly characterized, whilst GBSs prevalence amongst COVID-19 patients has not been previously systematically evaluated using a meta-analytical approach.
METHODS
A systematic review and meta-analysis of observational cohort and case series studies reporting on the occurrence, clinical characteristics and outcomes of patients with COVID-19-associated GBSs was performed. A random-effects model was used to calculate pooled estimates and odds ratios (ORs) with corresponding 95% confidence intervals (CIs), compared to non-COVID-19, contemporary or historical GBSs patients.
RESULTS
Eighteen eligible studies (11 cohorts, seven case series) were identified including a total of 136,746 COVID-19 patients. Amongst COVID-19 patients, including hospitalized and non-hospitalized cases, the pooled GBSs prevalence was 0.15‰ (95% CI 0%-0.49‰; I = 96%). Compared with non-infected contemporary or historical controls, patients with SARS-CoV-2 infection had increased odds for demyelinating GBSs subtypes (OR 3.27, 95% CI 1.32%-8.09%; I = 0%). In SARS-CoV-2-infected patients, olfactory or concomitant cranial nerve involvement was noted in 41.4% (95% CI 3.5%-60.4%; I = 46%) and 42.8% (95% CI 32.8%-53%; I = 0%) of the patients, respectively. Clinical outcomes including in-hospital mortality were comparable between COVID-19 GBSs patients and non-infected contemporary or historical GBSs controls.
CONCLUSION
GBSs prevalence was estimated at 15 cases per 100,000 SARS-CoV-2 infections. COVID-19 appears to be associated with an increased likelihood of GBSs and with demyelinating GBSs variants in particular.
Topics: COVID-19; Guillain-Barre Syndrome; Hospital Mortality; Humans; Prevalence; SARS-CoV-2
PubMed: 33837630
DOI: 10.1111/ene.14860