Depressive disorder and elevated risk of bell's palsy: a nationwide propensity score-weighting study.

BACKGROUND: Prior studies have reported a potential relationship between depressive disorder (DD), immune function, and inflammatory response. Some studies have also confirmed the correlation between immune and inflammatory responses and Bell's palsy. Considering that the pathophysiology of these two diseases has several similarities, this study investigates if DD raises the risk of developing Bell's palsy. METHODS: This nationwide propensity score-weighting cohort study utilized Taiwan National Health Insurance data. 44,198 patients with DD were identified as the DD cohort and 1,433,650 adult subjects without DD were identified as the comparison cohort. The inverse probability of treatment weighting (IPTW) strategy was used to balance the differences of covariates between two groups. The 5-year incidence of Bell's palsy was evaluated using the Cox proportional-hazard model, presenting results in terms of hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS: The average age of DD patients was 48.3 ± 17.3 years, and 61.86% were female. After propensity score-weighting strategy, no significant demographic differences emerged between the DD and comparison cohort. The Cox proportional hazards model revealed a statistically significant adjusted IPTW-HR of 1.315 (95% CI: 1.168-1.481) for Bell's palsy in DD patients compared to comparison subjects. Further independent factors for Bell's palsy in this model were age (IPTW-HR: 1.012, 95% CI: 1.010-1.013, p < 0.0001), sex (IPTW-HR: 0.909, 95% CI: 0.869-0.952, p < 0.0001), hypertension (IPTW-HR: 1.268, 95% CI: 1.186-1.355, p < 0.0001), hyperlipidemia (IPTW-HR: 1.084, 95% CI: 1.001-1.173, p = 0.047), and diabetes (IPTW-HR: 1.513, 95% CI: 1.398-1.637, p < 0.0001) CONCLUSION: This Study confirmed that individuals with DD face an elevated risk of developing Bell's palsy. These findings hold significant implications for both clinicians and researchers, shedding light on the potential interplay between mental health and the risk of certain physical health outcomes.

Has Coranavirus Disease 2019 Changed the Incidence and Outcome of Bell's Palsy?

BACKGROUND: Objectives: (1) To determine whether the incidence of Bell's Palsy (BP) increased during the pandemic. (2) To investigate whether the outcomes of patients with BP and COVID-19 infection or vaccination differ from those in the pre-pandemic era. METHODS: Patients with BP were studied in 2 periods retrospectively (March 2021-March 2022 and August 2018-August 2019). A prospective study from March 2021 to March 2022 was also performed. Primary outcome was grade ≤Ⅱ in the House-Brackmann (HB) and/or >70 in the Sunnybrook facial grading system (SFGS) scales at the 12-week visit. Reverse transcriptase polymerase chain reaction (PCR) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and enzyme-linked immunosorbent assay-based SARS-CoV-2 immuonoglobulin G (IgG) test (blood) were measured. RESULTS: About 162 and 196 patients with BP were identified between March 2021 and March 2022 and August 2018 and August 2019, respectively. Forty-seven patients (29%) entered the prospective study; 85% had HB grades I or II, while 92% had an SFGS score of 71-100 at the last visit. Only 3 patients (6.5%) had a positive PCR during the initial episode, whereas 35 patients (77%) had positive IgG SARS-CoV-2. There was no association between positive PCR and facial function outcomes. Of the 162 patients, 105 (67%) had received COVID-19 vaccine. In 23 of them (22%), the paralysis appeared within the first 30 days after a vaccine dose. CONCLUSION: Coronavirus disease 2019 did not increase the incidence of BP. A direct association between the coronavirus and BP outcome cannot be established. The considerable number of patients developing BP within the first month suggests a possible association between COVID-19 vaccines and BP.

Diabetes Mellitus and Acute Facial Palsy: A Nationwide Population-Based Study.

INTRODUCTION: Acute facial palsy, characterized by sudden hemifacial weakness, significantly impacts an individual's quality of life. Despite several predisposing factors identified for acute facial palsy, the specific relationship between diabetes mellitus (DM) and acute facial palsy has not been comprehensively explored in recent studies. The aim of the study was to assess the risk of acute facial palsy in patients with DM using a nationwide population sample cohort. METHODS: DM cohort and non-DM cohort were built using the Korean National Health Insurance Service-Sample Cohort which represents the entire population of the Republic of Korea from January 2002 to December 2019. The DM cohort comprised 92,872 patients with a record of medication and a diagnosis of DM. Individuals who had facial palsy before the diagnosis of DM were excluded. A comparison cohort comprised 1,012,021 individuals without DM matched sociodemographically in a 1:4 ratio. The incidence of Bell's palsy (BP) and Ramsay Hunt syndrome (RHS) were evaluated in both cohorts. The risk factors for acute facial palsy were also assessed. RESULTS: Among the 92,868 patients in the DM cohort, the incidence rate (IR) of BP and RHS were 31.42 (confidence interval [CI], 30.24-32.63) and 4.58 per 10,000 person-years (CI, 4.14-5.05), respectively. Among the 371,392 individuals in the non-DM cohort, the IR of BP was 22.11 per 10,000 person-years (CI, 21.62-22.59) and the IR of RHS was 2.85 per 10,000 person-years (CI, 2.68-3.02). IR ratios for BP and RHS were 1.42 (CI, 1.36-1.48) and 1.61 (CI, 1.43-1.80). In multivariate analysis, DM (hazard ratio [HR] 1.428), age (HR 1.008), and high comorbidity score (HR 1.051) were associated with increased risk of BP, and male (HR 0.803) and living in metropolis (HR 0.966) decreased the risk of BP. And DM (HR 1.615), high comorbidity score (HR 1.078), and living in metropolis (HR 1.201) were associated with increased risk for RHS. CONCLUSION: This study suggests that patients with DM had an increased risk of acute facial palsy including BP and RHS.

Bell's Palsy and COVID-19: Insights from a Population-Based Analysis.

Background: Coronavirus disease 2019 (COVID-19) has been linked to Bell's palsy and facial paralysis. Studies have also shown increased risk of Bell's palsy in unvaccinated COVID-19 patients. Objective: To compare the relationship between Bell's palsy and COVID-19 infection and vaccination. Design: This is a retrospective longitudinal study. Methods: The COVID-19 research network was used to identify patients with facial palsy presenting to 70 health care organizations in the United States. The incidence of Bell's palsy was measured within an 8-week window after COVID-19 test or vaccination event in identified patients. Results: Incidence of facial palsy diagnosis (0.99%) was higher than the background rate within 2 months of COVID-19 infection. When compared with their negative counterparts, patients with COVID-19 infection had significantly higher risk of Bell's palsy (risk ratio [RR] = 1.77, p < 0.01) and facial weakness (RR = 2.28, p < 0.01). Risk ratio was also amplified when evaluating Bell's palsy (RR = 12.57, p < 0.01) and facial palsy (RR = 44.43; p < 0.01) in COVID-19-infected patients against patients who received COVID-19 vaccination. Conclusion: In our patient population, there is a higher risk of developing facial palsy within 2 months of COVID-19 infection versus vaccination. Vaccinated patients are not at higher risk of developing facial palsy.

The Rate of Occult Lesion Diagnosis in a Large Bell's Palsy Cohort.

OBJECTIVES: We characterize occult lesion diagnosis rates after initial Bell's palsy diagnoses. METHODS: A de-identified database of all facial palsy patients who presented to an extensive health care system across 22 years was created using Epic SlicerDicer. Among patients with Bell's palsy diagnoses, we extracted demographic and any subsequent occult lesion diagnosis data across various clinical sites. Descriptive and multivariable regression analyses comparing patients with occult lesion diagnoses made at different time points were included. RESULTS: Among the total 3912 facial palsy patients, 2240 had Bell's palsy diagnoses, of which 217 (9.7%) had subsequent lesion diagnoses at a median (IQR) of 12.3 (4.2, 23.8) months, consisting of cranial nerve neoplasms (62.2%), parotid gland neoplasms (34.1%), and cholesteatomas (3.7%). Although a large proportion of total lesions were diagnosed within the first 3 months (19.8%), 69.5% were diagnosed after 6 months. There were no demographic differences among patients diagnosed with different lesion types, but Asian patients were more likely to be diagnosed with occult lesions after 12 months after Bell's palsy diagnosis compared with white patients (odds ratio = 6.2, p = 0.001). CONCLUSIONS: In one of the largest Bell's palsy cohorts to date, we identified a 9.7% occult lesion diagnosis rate at a median of 12.3 months after Bell's palsy diagnosis. These data underscore the importance of timely workup for occult lesions in cases of facial palsy with no signs of recovery after 3-4 months. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:911-918, 2024.

Pain in children with Bell's palsy: secondary analysis of a randomised controlled trial.

OBJECTIVE: To describe the prevalence and severity of pain experienced by children with Bell's palsy over the first 6 months of illness and its association with the severity of facial paralysis. METHODS: This was a secondary analysis of data obtained in a phase III, triple-blinded, randomised, placebo-controlled trial of prednisolone for the treatment of Bell's palsy in children aged 6 months to <18 years conducted between 13 October 2015 and 23 August 2020 in Australia and New Zealand. Children were recruited within 72 hours of symptom onset and pain was assessed using a child-rated visual analogue scale (VAS), a child-rated Faces Pain Score-Revised (FPS-R) and/or a parent-rated VAS at baseline, and at 1, 3 and 6 months until recovered, and are reported combined across treatment groups. RESULTS: Data were available for 169 of the 187 children randomised from at least one study time point. Overall, 37% (62/169) of children reported any pain at least at one time point. The frequency of any pain reported using the child-rated VAS, child-rated FPS-R and parent-rated VAS was higher at the baseline assessment (30%, 23% and 27%, respectively) compared with 1-month (4%, 0% and 4%, respectively) and subsequent follow-up assessments. At all time points, the median pain score on all three scales was 0 (no pain). CONCLUSIONS: Pain in children with Bell's palsy was infrequent and primarily occurred early in the disease course and in more severe disease. The intensity of pain, if it occurs, is very low throughout the clinical course of disease. TRIAL REGISTRATION NUMBER: ACTRN12615000563561.

Bell Palsy: Facts and Current Research Perspectives.

Bell palsy is a non-progressive neurological condition characterized by the acute onset of ipsilateral seventh cranial nerve paralysis. People who suffer from this type of facial paralysis develop a droop on one side of their face, or sometimes both. This condition is distinguished by a sudden onset of facial paralysis accompanied by clinical features such as mild fever, postauricular pain, dysgeusia, hyperacusis, facial changes, and drooling or dry eyes. Epidemiological evidence suggests that 15 to 23 people per 100,000 are affected each year, with a recurrence rate of 12%. It could be caused by ischaemic compression of the seventh cranial nerve, which could be caused by viral inflammation. Pregnant women, people with diabetes, and people with respiratory infections are more likely to have facial paralysis than the general population. Immune, viral, and ischemic pathways are all thought to play a role in the development of Bell paralysis, but the exact cause is unknown. However, there is evidence that Bell's hereditary proclivity to cause paralysis is a public health issue that has a greater impact on patients and their families. Delay or untreated Bell paralysis may contribute to an increased risk of facial impairment, as well as a negative impact on the patient's quality of life. For management, antiviral agents such as acyclovir and valacyclovir, and steroid treatment are recommended. Thus, early diagnosis accompanied by treatment of the uncertain etiology of the disorder is crucial. This paper reviews mechanistic approaches, and emerging medical perspectives on recent developments that encounter Bell palsy disorder.

Sudden Sensorineural Hearing Loss and Facial Palsy in Patients with Vestibular Schwannoma Based on the Population Data of Korea.

BACKGROUND: The prevalence of sudden sensorineural hearing loss and facial palsy in patients with vestibular schwannoma and the association of sudden sensorineural hearing loss or facial palsy with vestibular schwannoma were investigated based on the population data of Korea. METHODS: This retrospective study used the Korean National Health Insurance Service data. Patients with vestibular schwannoma and those with a previous history of sudden sensorineural hearing loss or facial palsy were identified based on diagnostic, medication, magnetic resonance imaging, or audiometric codes from 2005 to 2020. The control group was established with propensity score matching. The risk for vestibular schwannoma in patients with a previous history of sudden sensorineural hearing loss or facial palsy was analyzed. RESULTS: There were 5751 patients in the vestibular schwannoma group and 23004 in the control group. The rate of patients with a previous history of sudden sensorineural hearing loss in the vestibular schwannoma group (25.8%) was significantly higher than in the control group (P -lt; .0001), as was the rate of patients with a previous history of facial palsy in the vestibular schwannoma group (4.7%) (P -lt; .0001). Previous history of sudden sensorineural hearing loss was a significant risk factor for vestibular schwannoma (hazard ratio=7.109, 95% confidence interval=6.696-7.547). Previous history of facial palsy was also a significant risk factor for vestibular schwannoma (hazard ratio=3.048, 95% confidence interval=2.695-3.447). CONCLUSION: The prevalence of sudden sensorineural hearing loss or facial palsy was significantly higher in patients with vestibular schwannoma than in those without vestibular schwannoma. Based on the population data of Korea, sudden sensorineural hearing loss and facial palsy were significant risk factors for vestibular schwannoma.

Effect of temperature and air pressure on the incidence of Bell's palsy in Hangzhou: a distributed lag non-linear analysis.

The etiology of Bell's palsy (BP) is currently unknown, and the findings from previous studies examining the association between seasonal or meteorological factors and BP have been inconsistent. This research aims to clarify this relationship by analyzing a larger dataset and employing appropriate statistical methods. Data from 5387 patients with BP treated at Zhejiang Provincial Hospital of Traditional Chinese Medicine in Hangzhou, Zhejiang Province, from May 1, 2018, to June 30, 2023, was gathered. We assessed the temporal distribution of meteorological factors and the incidence of BP across seasons and months. A distributed lag non-linear model was used to further investigate the lagged and overall effects of temperature and air pressure on the onset of BP. The temporal distribution of BP incidence revealed the highest average number of cases occurring in December and the lowest in June. A correlation existed between BP episodes and temperature or air pressure. The model revealed a higher relative risk during periods of low temperature and high air pressure, characterized by a time lag effect. This correlation was notably more pronounced in female patients and individuals in the young and middle-aged groups. Our findings suggest that exposure to low temperatures and high air pressure constitute risk factors for BP development.

Risk of Bell's palsy following SARS-CoV-2 infection: a nationwide cohort study.

OBJECTIVES: Despite some evidence of an increased risk of neurologic symptoms following viral vector COVID-19 vaccine administration, it is unclear whether SARS-CoV-2 infection is associated with Bell's palsy (BP), especially over a long enough follow-up period. METHODS: The study population of this nationwide population-based study was derived from the South Korean population, including 11 593 365 and 36 565 099 participants with and without COVID-19, respectively. The Fine and Gray's regression model was utilized to calculate the adjusted subdistribution hazard ratio (aSHR), considering death as a competing risk, to assess the association between SARS-CoV-2 infection and the risk of BP. All participants were followed up from 1 December 2021, until the incident BP, SARS-CoV-2 infection, death, or 31 March 2022. Subgroup analyses were conducted based on participants' vaccination status (completion of the primary series vs. unvaccinated). RESULTS: COVID-19 was associated with an increased risk of BP in all participants (aSHR, 1.24; CI, 1.19-1.29). However, the size of the COVID-19-related BP risk was significantly lower among those who completed the primary series of the COVID-19 vaccine (aSHR, 1.20; 95% CI, 1.15-1.25) compared to those who were unvaccinated (aSHR, 1.84; 95% CI, 1.59-2.12; p for interaction: <0.001). The severity of COVID-19 exhibited a gradual escalation in BP risk for both vaccinated and unvaccinated individuals. DISCUSSION: While both unvaccinated individuals and those who completed the primary series of the COVID-19 vaccine may be at an increased risk of developing BP due to COVID-19, the risk appears to be lower among those who completed the vaccination.

Examining the relationship between COVID-19 and Bell's palsy: Experience of a single tertiary care center.

BACKGROUND: While the etiology of Bell's palsy (BP) is largely unknown, current evidence shows it may occur secondary to the immune response following a viral infection. Recently, BP has been reported as a clinical manifestation of coronavirus disease (COVID-19). OBJECTIVES: To investigate an association between COVID-19 infection and BP. Additionally, to evaluate the need for COVID-19 testing in patients who present with BP. METHODS: Hospital records of patients who presented to a single tertiary care center with BP in 2020 and 2021 were reviewed for presenting symptoms, demographics, COVID-19 infection and vaccination status. RESULTS: There was no statistically significant difference between patients with BP who had a positive or negative COVID test in terms of sex, BMI, age, race, smoking history or alcohol use. All 7 patients with BP and a positive COVID test were unvaccinated. Of the total cohort of 94 patients, 82 % were unvaccinated at the time of the study. None of the 17 patients who were vaccinated had a positive COVID test. A history of BP showed no statistical significance (10.3 % vs 14.3 %, p-value 0.73). CONCLUSION: We discovered a limited cohort of patients who underwent COVID-19 testing at the time of presentation for BP. Though there have been recent studies suggesting a COVID-19 and BP, we were unable to clearly identify a relationship between COVID-19 and BP. Interestingly, all patients with facial paralysis and COVID-19 were unvaccinated. To further study this relationship, we recommend consideration of a COVID-19 test for any patient that presents with facial paralysis.

Association Between Thyroid-Stimulating Hormone Level and Bell's Palsy.

OBJECTIVE: To investigate whether dysregulated thyroid hormone function is associated with Bell's palsy. STUDY DESIGN: Cross-sectional. SETTING: Electronic medical record database of Clalit Health Services (CHS). CHS is an Israeli payer-provider, integrated health care system, serving >4.5 million members (54% of the Israeli population). PATIENTS: Older than 18 years with Bell's palsy, during 2002 to 2019. INTERVENTIONS: None. METHODS: A total of 1,374 patients with Bell's palsy who had thyroid-stimulating hormone (TSH) blood levels measured up to 60 days before the palsy were matched (1:2) for age and sex with 2,748 controls who had TSH blood levels and no history of Bell's palsy. RESULTS: Retrospective review of the CHS database, from 2002 to 2019 yielded 11,268 patients with Bell's palsy, of which, 1,374 met the inclusion criteria. Mean age was 57.9 years, and 61.4% were female. A higher percentage of patients in the Bell's palsy group had low TSH (≤0.55 mIU/L) compared with controls (5.7% vs. 3.6%, p < 0.001). Low TSH compared with TSH > 0.55 mIU/L, was independently associated with 1.45-fold increased odds for having Bell's palsy (95% CI 1.11-2.02, p < 0.001), when controlled for age, sex, body mass index, diabetes, hypertension, prior cerebrovascular accident, hemoglobin level, and purchasing thyroid hormone drugs. Among the patients with TSH ≤ 0.55 mIU/L, 95.5% had normal free thyroxin and 97.7% had normal free triiodothyronine levels (subclinical hyperthyroidism). For 47.1% of patients, TSH remained ≤0.55 mIU/L, 3 to 12 months after the Bell's palsy occurred and most patients had normal free thyroxin (95.4%) and normal free triiodothyronine (91.8%). CONCLUSIONS: Subclinical hyperthyroidism is independently associated with Bell's palsy after controlling for multiple confounding factors.

Sunshine duration and solar radiation contributed to severe Bell's palsy: An 11-year time series analysis based on a distributed lag non-linear model model.

Although previous studies have suggested that meteorological factors are associated with Bell's palsy, articles on this topic are rare and the results are inconsistent. We aim to reveal the relationship between exposure to different meteorological factors and the onset of severe Bell's palsy (SBP) with daily data. A case-crossover study based on time-series data was applied, and the minimum risk value of each climatic factor was set as the reference value. We fitted a distributed lag non-linear model (DLNM) which applied quasi-Poisson regression to evaluate the exposure-response association and the lag-response association of meteorological factors on the occurrence of SBP. The mode value and per-decile interval value of each meteorological factor were all included in the analysis. Sensitivity analyses were conducted to test the robustness of results. A total of 863 SBP patients (474 males and 389 females) from 7 hospitals in the Shenzhen Futian District were selected from January 2009 to February 2020. The highest relations effect was tested in the cumulative exposure-response result shown as follows; mean temperature at the minimum value 15.3°C with RR of 10.370 (1.557-69.077) over lag 0 to 13; relative humidity at the 30th value 71% with RR of 8.041 (1.016-63.616) over lag 0 to 14; wind speed at the 90th value 31 (0.1 m/s) with RR of 1.286 (1.038-1.593) over lag 0; mean air pressure at the 30th value 1001.4 (pa) with RR of 9.052 (1.039-78.858) over lag 0 to 5; visibility at the 80th value 26.5 (km) with RR of 1.961 (1.005-1.423) over lag 0 to 2; average total cloud cover at the max value 100 (%) with RR 1.787 (1.014-3.148) over lag 0 to 2; sunshine duration at the 10th value 0.1 (h) with RR of 4.772 (1.018-22.361); daily evaporation shows no relationship in the cumulative result; daily average solar radiation at the minimum value 0 (W/m2) with RR of 5.588 (1.184-26.382). There is a relationship between wind speed and the onset of SBP, while mean air pressure, visibility, and average total cloud cover, especially sunshine duration and solar radiation which showed a strong effect, may be associated with severe clinical symptoms of SBP. Mean temperature and relative humidity may affect the course of SBP.

Bell's Palsy After Vaccination Against Covid-19: A Systematic Review and Meta-analysis.

OBJECTIVE: This systematic review and meta-analysis aimed to identify studies reporting the incidence of Bell's Palsy after vaccination against coronavirus disease 2019 (Covid-19) and assess whether this incidence is greater than among the general population. DATA SOURCES: PubMed, Embase, CINAHL, and Web of Science. REVIEW METHODS: A systematic review was performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Databases were searched from inception to May 9, 2022, for studies reporting the incidence of Bell's Palsy among individuals vaccinated against Covid-19 and control populations. Meta-analyses of odds ratios (ORs) were performed to compare the incidence of Bell's Palsy in these groups. RESULTS: We identified 7 studies reporting the incidence of Bell's Palsy after vaccination and among the general population, including 20,234,931 total vaccinated patients. The length of postvaccination follow-up ranged from 7 to 43 days in these studies. The incidence of Bell's Palsy was not significantly greater among vaccinated individuals (OR: 1.06; 95% confidence interval [CI]: 0.65-1.71; p = .82). Stratifying by dose, the incidence of Bell's Palsy was not significantly greater after receiving either the first dose (OR: 0.84; 95% CI: 0.47-1.49; p = .54) or second dose (OR: 1.02; 95% CI: 0.58-1.79; p = .96). CONCLUSION: Among the available evidence, the incidence of Bell's Palsy after vaccination against Covid-19 is comparable to that of the general unvaccinated population. Patient counseling should provide reassurance that there is no known association between Bell's Palsy and Covid-19 vaccination.

Association of Influenza Vaccination With Risk of Bell Palsy Among Older Adults in Taiwan.

Importance: Annual administration of the influenza vaccine (fluVc) is currently the most effective method of preventing the influenza virus in older adults. However, half of adults older than 65 years remain unvaccinated in Taiwan, possibly because of concern about adverse events, such as Bell palsy (BP). Currently, studies on the association between fluVc and risk of BP are inconsistent. Objective: To determine whether the incidence of BP increases following fluVc in older adults. Design, Setting, and Participants: A self-controlled case series study design was used. Days 1 through 7, days 8 through 14, days 15 through 30, and days 31 through 60 following fluVc were identified as risk intervals, and days 61 through 180 were considered the control interval. A total of 4367 vaccinated individuals aged 65 years or older who developed BP within 6 months following fluVc were enrolled. Population-based retrospective claims data were obtained between 2010 and 2017; data were analyzed from April 2022 through September 2022. Exposure: Government-funded seasonal fluVc. Main Outcomes and Measures: The outcome of interest was BP onset in risk intervals compared with control intervals. Three or more consecutive diagnoses of BP within 60 days following fluVc were used as the definition of a patient with BP. Poisson regression was used to analyze the incidence rate ratio (IRR) of risk intervals compared with control intervals. Results: In total, 13 261 521 patients who received the fluVc were extracted from the National Health Insurance Research Database in Taiwan from January 1, 2010, to December 31, 2017. Of those, 7 581 205 patients older than 65 years old met the inclusion criteria. The number of patients with BP diagnosed within 6 months following fluVc enrolled for risk analysis was 4367 (mean [SD] age, 74.19 [5.97] years; 2349 [53.79%] female patients). The incidence rate of BP among all observed fluVc older adults was 57.87 per 100 000 person-years. The IRRs for BP on days 1 through 7, days 8 through 14, and days 15 through 30 were 4.18 (95% CI, 3.82-4.59), 2.73 (95% CI, 2.45-3.05), and 1.67 (95% CI, 1.52-1.84), respectively. However, there was no increase during days 31 through 60 (IRR, 1.06; 95% CI, 0.97-1.16). The postvaccination risk of BP was consistent across all subgroups stratified by sex, age group, and baseline conditions. Conclusions and Relevance: The present self-controlled case series indicated that the risk of BP in individuals older than 65 years increased within the first month, especially within the first week, following fluVc. But overall, the adverse event rate of BP was low, and considering the morbidity and mortality of influenza infection, the benefits of fluVc still outweigh the risks.

Association of SARS-CoV-2 Vaccination or Infection With Bell Palsy: A Systematic Review and Meta-analysis.

Importance: Bell palsy (BP) has been reported as an adverse event following the SARS-CoV-2 vaccination, but neither a causative relationship nor a higher prevalence than in the general population has been established. Objective: To compare the incidence of BP in SARS-CoV-2 vaccine recipients vs unvaccinated individuals or placebo recipients. Data Sources: A systematic search of MEDLINE (via PubMed), Web of Science, Scopus, Cochrane Library, and Google Scholar from the inception of the COVID-19 report (December 2019) to August 15, 2022. Study Selection: Articles reporting BP incidence with SARS-CoV-2 vaccination were included. Data Extraction and Synthesis: This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline and was conducted with the random- and fixed-effect models using the Mantel-Haenszel method. The quality of the studies was evaluated by the Newcastle-Ottawa Scale. Main Outcomes and Measures: The outcomes of interest were to compare BP incidence among (1) SARS-CoV-2 vaccine recipients, (2) nonrecipients in the placebo or unvaccinated cohorts, (3) different types of SARS-CoV-2 vaccines, and (4) SARS-CoV-2-infected vs SARS-CoV-2-vaccinated individuals. Results: Fifty studies were included, of which 17 entered the quantitative synthesis. Pooling 4 phase 3 randomized clinical trials showed significantly higher BP in recipients of SARS-CoV-2 vaccines (77 525 vaccine recipients vs 66 682 placebo recipients; odds ratio [OR], 3.00; 95% CI, 1.10-8.18; I2 = 0%). There was, however, no significant increase in BP after administration of the messenger RNA SARS-CoV-2 vaccine in pooling 8 observational studies (13 518 026 doses vs 13 510 701 unvaccinated; OR, 0.70; 95% CI, 0.42-1.16; I2 = 94%). No significant difference was found in BP among 22 978 880 first-dose recipients of the Pfizer/BioNTech vaccine compared with 22 978 880 first-dose recipients of the Oxford/AstraZeneca vaccine (OR, 0.97; 95% CI, 0.82-1.15; I2 = 0%). Bell palsy was significantly more common after SARS-CoV-2 infection (n = 2 822 072) than after SARS-CoV-2 vaccinations (n = 37 912 410) (relative risk, 3.23; 95% CI, 1.57-6.62; I2 = 95%). Conclusions and Relevance: This systematic review and meta-analysis suggests a higher incidence of BP among SARS-CoV-2-vaccinated vs placebo groups. The occurrence of BP did not differ significantly between recipients of the Pfizer/BioNTech vs Oxford/AstraZeneca vaccines. SARS-CoV-2 infection posed a significantly greater risk for BP than SARS-CoV-2 vaccination.

Bell's Palsy in Pregnancy and Postpartum: A Retrospective Case-Control Study of 182 Patients.

OBJECTIVE: To assess the incidence of Bell's palsy in pregnant and postpartum women. Additionally, to compare facial outcomes in terms of Sunnybrook score following Bell's palsy with regard to corticosteroid treatment and other confounding factors. STUDY DESIGN: Retrospective case-control study. SETTING: University Hospital, Stockholm, Sweden. METHODS: All women with Bell's palsy in pregnancy or postpartum (6 weeks after birth) with a computerized medical chart in the Stockholm Region 2005 to 2015 were included. The total number of births in the region during this period was retrieved from the Swedish Medical Birth Register. Nonpregnant age-matched women with Bell's palsy served as controls. Characteristics, medication, and Sunnybrook scores were collected. Risk factors for incomplete recovery (Sunnybrook score <96) at 3 months were calculated by logistic regression. RESULTS: In total, 182 pregnant and postpartum women with Bell's palsy were identified. The estimated incidence among pregnant and postpartum women was 60.5/100,000 person-years. The mean Sunnybrook score at 3 months was 74 among pregnant and postpartum women and 83 for controls (p = .002). At 12 months, Sunnybrook score was 81 and 89, respectively (p = .017). Only one-third of the pregnant women received corticosteroid treatment. CONCLUSION: The incidence of Bell's palsy in pregnancy and postpartum was 60.5 per 100,000 women and year in the Stockholm Region. Sunnybrook score was poorer in pregnant women compared with postpartum and nonpregnant women throughout. Corticosteroid treatment had little effect on any patients, however, only one-third of the pregnant women received this treatment.

Risk and characteristics of Bell's palsy in adults as an adverse event following COVID-19 vaccination: a retrospective study.

BACKGROUND: Although an association between COVID-19 vaccination and Bell's palsy (BP) has been reported, a clear causal relationship has not been elucidated. We investigated the risk and clinical characteristics of BP after COVID-19 vaccination. METHODS: This retrospective chart review evaluated the association between COVID-19 vaccination and BP by comparing the number of patients diagnosed with BP during the pre-COVID-19 vaccination period (March 2018-February 2021) and the COVID-19 mass vaccination period (March 2021-February 2022). We then compared vaccine-related (time between vaccination and BP onset < 42 days) and -unrelated (time interval ≥ 42 days or non-vaccination) clinical characteristics in newly diagnosed patients with BP. RESULTS: BP occurred more during the COVID-19 vaccination period than in the previous three pre-vaccination years. Thirteen patients developed BP within 42 days of vaccination. All patients, except one, developed BP after mRNA-based vaccination, with most cases (9/13, 69.2%) occurring after the second or third dose. Thirteen patients with vaccine-related BP were younger (age 43.92 ± 13.14 vs. 54.32 ± 16.01 years; p = 0.033) and more frequently experienced taste changes (58.8% vs. 10.9%; p = 0.002) than 52 patients with vaccine-unrelated BP. Patients with vaccine-related BP had a greater likelihood of good and faster (p = 0.042) facial nerve function recovery than those with vaccine-unrelated BP (100% vs. 78%). CONCLUSION: COVID-19 vaccines, especially mRNA-based vaccines, may be associated with BP cases with distinctive clinical characteristics, which occur more frequently in young individuals, are frequently accompanied by taste changes, and have fast and good recovery.

Messenger RNA Coronavirus Disease 2019 (COVID-19) Vaccination With BNT162b2 Increased Risk of Bell's Palsy: A Nested Case-Control and Self-Controlled Case Series Study.

BACKGROUND: Observable symptoms of Bell's palsy following vaccinations arouse concern over the safety profiles of novel coronavirus disease 2019 (COVID-19) vaccines. However, there are only inconclusive findings on Bell's palsy following messenger (mRNA) COVID-19 vaccination. This study aims to update the previous analyses on the risk of Bell's palsy following mRNA (BNT162b2) COVID-19 vaccination. METHODS: This study included cases aged ≥16 years with a new diagnosis of Bell's palsy within 28 days after BNT162b2 vaccinations from the population-based electronic health records in Hong Kong. Nested case-control and self-controlled case series (SCCS) analyses were used, where the association between Bell's palsy and BNT162b2 was evaluated using conditional logistic and Poisson regression, respectively. RESULTS: Totally 54 individuals were newly diagnosed with Bell's palsy after BNT162b2 vaccinations. The incidence of Bell's palsy was 1.58 (95% confidence interval [CI], 1.19-2.07) per 100 000 doses administered. The nested case-control analysis showed significant association between BNT162b2 vaccinations and Bell's palsy (adjusted odds ratio [aOR], 1.543; 95% CI, 1.123-2.121), with up to 1.112 excess events per 100 000 people who received 2 doses of BNT162b2. An increased risk of Bell's palsy was observed during the first 14 days after the second dose of BNT162b2 in both nested case-control (aOR, 2.325; 95% CI, 1.414-3.821) and SCCS analysis (adjusted incidence rate ratio, 2.44; 95% CI, 1.32-4.50). CONCLUSIONS: There was an overall increased risk of Bell's palsy following BNT162b2 vaccination, particularly within the first 14 days after the second dose, but the absolute risk was very low.

Vaccines and Bell's palsy: A narrative review.

The association between vaccines and peripheral facial palsy (PFP), an issue that has been the subject of debate for many years, has been raised again following results of clinical trials assessing mRNA based COVID-19 vaccines. To review the available literature on this topic, PubMed was searched from inception until February 25, 2022. Inclusion criteria were case reports with documented rechallenge and comparative epidemiological studies. Cases of COVID-19 vaccine-induced PFP with available data on vaccine rechallenge were also identified from Vigibase until December 31, 2021. Of the 347 articles retrieved, 32 comparative epidemiological studies, 1 meta-analysis and 4 case reports met our criteria, of which 13 involved COVID-19 vaccines. Eight studies found an association between at least one vaccine and the occurrence of PFP, whereas 24 did not. Positive studies involved seasonal or pandemic H1N1 influenza vaccines administered parenterally (4 studies) or intranasally (1 study with a toxin-adjuvanted vaccine), BNT162b2, a mRNA COVID-19 vaccine (1 disproportionality analysis and 1 observed-to-expected analysis) and an inactivated virus COVID-19 vaccine (CoronaVac®) (1 study combining a case-control and an observed-to-expected approach). Strong evidence was found only for the intranasal influenza vaccine while other positive studies detected only a marginal association between PFP and vaccination. Of the four case reports with documented rechallenge, only two were positive and involved an influenza vaccine and tozinameran in one case each. In Vigibase, rechallenge was documented in 49 reports with 29 (59.2%) cases being negative and 20 (40.8%) positive. The available data did not confirm an excess risk of PFP after vaccination in most studies. Moreover, of the eight epidemiological studies suggesting a possible excess risk of PFP after any vaccine, three were disproportionality analyses and two observed-to excepted analyses, suggesting great caution should be taken when interpreting these results.