**3. Hypoxia and CNS damage**

Reduced oxygenation caused by SARS-CoV-2 mediated pneumonia in COVID-19 can lead to severe hypoxia of CNS. In many cases of patients that have died of COVID-19, severe hypoxia of the CNS has been observed [15]. There is an acute hypoxic-ischemic injury with neuronal loss and the presence of apoptotic neurons. This kind of CNS damage is unrelated to direct viral infection of the CNS or indirect effects mediated by the virus-induced immune response within the CNS but a consequence of the strongly reduced oxygenation of erythrocytes in the lung. This reduced oxygenation of erythrocytes results in hypoxia of the CNS. Besides hypoxia, at biopsy or autopsy in CNS microthrombi, thromboembolic disease, inflammation, and to the largest extent hemodynamic mediated changes were found [16].
