A systematic review of Bell's Palsy as the only major neurological manifestation in COVID-19 patients.

Background: Bell's palsy is an acute idiopathic paralysis of the facial nerve. The disease is caused by many viruses like Herpes simplex virus-1, Varicella zoster, Epstein-bar virus, Cytomegalovirus, Usutu virus, Human immunodeficiency virus, etc. Literature has reported few cases of COVID-19 patients with Bell's palsy as the only major neurological manifestation indicating the possible role of another virus in the etiopathogenesis of Bell's Palsy. This paper aims to evaluate the reported cases of COVID-19 positive patients, presented with Bell's palsy as the only major neurological manifestation from March 2020 to December 2020, and to investigate the association of SARS-CoV2 and Bell's palsy.
Materials and Methods: A systematic review of the published literature was performed using an electronic search in PubMed/Medline, Science Direct, Web of Science, Embase, J- STAGE, Google Scholar, China National Knowledge Infrastructure (CKNI) and Scopus databases, from March 2020 to Dec 2020 using keywords like 'COVID-19', 'SARS-CoV-2', 'Coronavirus', 'Bell's palsy', 'Facial nerve', 'First', 'Only',' Neurological', 'Manifestation'. The studies reviewed were case series and case reports regarding the subject.
Results: Search strategy revealed thirteen articles from March 2020 to Dec 2020 with a total of 20 cases of COVID-19 with Bell's palsy as the only major neurological manifestation.
Conclusion: Evidence of Bell's palsy as the only major neurological manifestation in COVID-19 patients signifies an important clinical finding but robust research is needed to investigate their association and the exact mechanisms by which SARS-CoV2 causes Bell's Palsy.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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