Fig. 2.

COVID-19 neurological entrance and main mechanisms of action: SARS-CoV-2 viruses could affect brain tissue and generate neurological symptomatology directly by neuroinvasion, arriving to the brain through several pathways such as: (1) the olfactory route via the trigeminal nerve, (2) the vagus nervous in connection with the lungs and (3) the gut-brain axis; or indirectly as a consequence of the effects of the systemic infection, such as hypoxia or hyperthermia. In both cases several mechanisms could be triggered such as BBB disruption, inflammation, and increased risk of secondary infections, among others, all of them being interconnected. The final result is the generation of brain dysfunction and the onset of the mentioned neurological symptomatology in COVID-19 patients.