Neurological manifestations of COVID-19 and its vaccines: an updated comprehensive review with an insight into pathophysiology

The COVID-19 pandemic caused by SARS-CoV-2 has had a significant global impact on the respiratory system and multiple organ systems, including the nervous system. Neurological manifestations associated with COVID-19 infection and its vaccines have been increasingly recognized, ranging from problems with smell and taste to more severe conditions such as encephalitis, stroke, and Guillain-Barré syndrome. This narrative review critically evaluates the neurological manifestations of COVID-19 infection and its vaccines, providing insights into potential pathophysiological mechanisms. A comprehensive literature search was conducted, and data were retrieved from various databases. The prevalence, types, and severity of neurological symptoms in COVID-19 patients were discussed. The possible mechanisms of neurological injury in COVID-19 were explored, including direct viral invasion, hypoxic brain injury, immune-mediated damage, and cerebrovascular injury. Furthermore, the review addressed the neurological complications associated with COVID-19 vaccination. While severe vaccine-related adverse effects remain rare, understanding their occurrence is essential for risk assessment and public health interventions. In conclusion, COVID-19 can affect the nervous system in various ways, leading to various neurological symptoms. Further research is necessary to enhance our understanding of these manifestations and develop effective preventive and treatment strategies to manage this global health crisis.