The synergistic role of viral infection and immune response in the pathogenesis of facial palsy.

Facial palsy refers to facial muscle paralysis and is typically brought about by viral infections, such as herpes simplex virus type 1 (HSV-1), herpes zoster virus (VZV), and SARS-CoV-2. While significant progress has been achieved in viral facial palsy pathogenesis, mechanisms of viral infection-immunity synergy are yet to be revealed. The authors of this article made an attempt to fill this gap by critically summarizing how viral infection causes inflammation and damage to the facial nerve through an immune response mechanism in the facial palsy pathogenesis. We also summarize the current treatment modalities and their respective efficacies. The article set the conditions under which viral infections caused by HSV-1, VZV, SARS-CoV-2, HIV, and EBV lead to facial paralysis and how the viruses infect the facial nerve, initiate an immune response, and cause nerve death. The impact involved direct viral invasion of neurons, immune evasion and induction of neuroinflammation. The review also discusses the primary role of T cells, B cells and innate immune cells in inducing or relieving the condition. The study emphasizes the need to understand the synergic effect of viral infection and immuneresponse of facial palsy as the foundation of the creation of more potent therapeutic strategies. The paper provides a detailed overview of complex interaction of immuneresponse and viral infection of facial palsy with significant level of importance regarding future research and clinical application.