Spectrum of neuropathological findings in a series of 13 COVID-19 patients

Introduction: COVID-19 has been associated with a broad spectrum of abnormalities in the central nervous system including inflammatory changes and coagulopathy. Methods: We present the neuropathological findings in the brains of 13 COVID-19 patients. We included the clinical history with focus on immunological status. Our neuropathological workup included sampling of representative brain areas with olfactory bulb, meninges and choroid plexus. Histological and immunohistological stainings for inflammation including activated microglia, for cerebrovascular pathology, as well as an immunohistochemical panel for neurodegenerative disorders were performed. Mean age of our cohort was 68 [33;90]. 4 patients had a previous diagnosis of a neurodegenerative disorder. Results: Postmortem evaluation revealed severe meningoencephalitis with multiple hemorrhagic infarctions (n = 1), multiple hemorrhagic infarctions (n = 1), major hemorrhages (n = 2) and hypoxic encephalopathy (n = 1). Isolated bulbar and meningeal inflammation was found in 3 patients. 5 patients did not have any neuropathological changes. Our neurodegenerative analysis detected FTLD-TDP, Alzheimer's disease neuropathological changes and hippocampal sclerosis. Conclusion: Our cohort confirms the variety of neuropathological findings in patients with COVID-19 with a range from isolated bulbitis/meningitis to full blown meningo-encephalitis with hemorrhagic infarcts. The pleiad in symptomatology suggests that other factors should be taken into account, considering the vulnerability of cerebral involvement as to the immunological status and the coagulopathy.