evidence: Although the cause of neuroinvasion and BBB damage in COVID-19 is still unclear, the extent of neurological injury and BBB damage appears to be related to the degree of cognitive impairment and severity of COVID-19 infection. Cranial nerves and the BBB may be important structures for direct and indirect interactions between SARS-CoV-2 and the brain. In this review, we assessed the potential involvement of neuroinvasion and BBB dysfunction in SARS-CoV-2 infection, exploring its impact on COVID-19-related cognitive dysfunction. [...] The olfactory nerve is mainly composed of olfactory receptor neurons and directly connects the nasal cavity and the CNS [52]. Some pathogens can infect olfactory sensory neurons and their axons that project into the olfactory bulb, which allows the viruses to bypass the BBB and reach the CNS through the so-called olfactory pathway [53]. In one study, of 38 patients with confirmed COVID-19, 73.7% were reported to have positive RT-PCR tests on nasopharyngeal swabs [54]. In a Spanish COVID-19 cohort, 36% of the patients initially presented with anosmia [55]. In a large European multicentre cohort of mild-to-moderate COVID-19 patients, 85.6% and 88.8%, respectively, had olfactory and taste dysfunction [56]. [...] Meinhardt J, Radke J, Dittmayer C, Franz J, Thomas C, Mothes R, Laue M, Schneider J, Brunink S, Greuel S, et al. Olfactory transmucosal SARS-CoV-2 invasion as a port of central nervous system entry in individuals with COVID-19. Nat Neurosci. 2021;24:168–75. https://doi.org/10.1038/s41593-020-00758-5.