Epidemiology, clinical features, and treatment modalities of facial nerve palsy in COVID-19 patients: a systematic review

Coronavirus disease 2019 (COVID-19) is responsible for a wide variety of multi-system clinical features. Facial nerve palsy (FNP) is identified as one of the neurological complications of the virus. This work aims to systematically review the clinical picture, laboratory/imaging findings, treatment options, and prognostic factors of FNP in COVID-19 patients.Using six online databases, a search was conducted to include all articles with patients infected with COVID-19 and presenting with unilateral or bilateral FNP. Screening for eligibility and data extraction were done by three and four independent reviewers, respectively. Descriptive analyses and data visualizations were done using Google Sheets. Survival analysis and Kaplan-Meier plotting were done by R software.The data from 22 studies included 32 patients who were infected with COVID-19 and presented with clinical features of FNP. Fourteen patients were male while 18 were female. FNP affected 29 patients unilaterally and 3 patients bilaterally. The imaging findings confirmed that complications of FNP were COVID-19 related. Additionally, antivirals combined with steroids had the lowest median time (21, IQR = 8) to clinical improvement compared to steroid-only (30, IQR = 15) and antiviral-only (33, IQR = 3.5) treatments.This study has shown a potential correlation between the increased incidence of FNP and COVID-19. We have also found that combining antivirals with steroids may have better outcomes in patients with FNP and COVID-19 although the evidence to support this claim is not strong enough. Further studies are required to assess the extent of linkage between the two conditions and how to properly manage FNP when encountered in COVID-19 patients.