Although pneumonia and acute respiratory failure are the most frequent and severe complications of patients with SARS-CoV-2 infection, many of them also develop neurological signs and symptoms. From sickness behavior to coma, neurological disorders are associated with impairment of consciousness and dysautonomia, resulting from brainstem dysfunction. We propose here that SARS-CoV-2 invasion via the olfactory and trigeminal nerves generates a local neuro-inflammatory process aggravated by systemic inflammatory responses and micro-circulatory ischemic process. In addition to its short and long-term neurological consequences, the COVID-19-related brainstem dysfunction compromises the adaptive response to stress and contributes to organ failure and death. The detection of brainstem dysfunction mainly relies on neurological examination and non-invasive methods, such as pupillometer and spectral analyses of heart rate and blood pressure. We review the existing evidence of brainstem involvement in the course of Covid-19, its main mechanisms, diagnostic strategies, and potential outcomes.

Brainstem; Neurotropism; COVID-19; Nucleus Tractus Solitarius; Olfaction, Neuroinflammation