Effects of social distancing on the incidence of Bell's palsy and sudden sensorineural hearing loss

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.

COVID-19 and Sudden Sensorineural Hearing Loss: A Systematic Review

A growing body of evidence suggests that patients with the 2019 Coronavirus disease (COVID-19) have a risk of developing sudden sensorineural hearing loss (SSNHL). The pathogenesis of COVID-19-related SSNHL remains unclear. This systematic review examined whether COVID-19 causes an increased incidence of SSNHL and the clinical characteristics of patients with COVID-19-related SSNHL according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. SSNHL usually developed between a few days and 2 months after the diagnosis of COVID-19, and a proportion of patients developed it before the diagnosis of COVID-19. The literature is inconsistent regarding whether COVID-19 causes an increased incidence of SSNHL, and this matter remains unclear. This review included 23 patients with COVID-19-related SSNHL, all adult patients with an average age of 43.1 years. Of these patients, 60.9% had accompanying tinnitus symptoms. Glucocorticoids are the preferred medication to treat COVID-19-related SSNHL. Intratympanic administration may be considered to reduce the side effects of the drug. Hearing tests are suggested when hearing loss is suspected in COVID-19 individuals, and if SSNHL is detected, prompt and aggressive treatment is vital. Large-scale, multicenter research on the pathophysiology, treatment, and prognosis of COVID-19- related SSNHL should be conducted in the future.