Neurologic involvement is well-recognized in coronavirus disease (COVID-19). This article reviews the neuroimaging manifestations of COVID-19 on CT and MRI, presenting cases from the New York City metropolitan region encountered by the authors during the first surge of the pandemic. The most common neuroimaging manifestations are acute infarcts with large clot burden and intracranial hemorrhage, including microhemorrhages. However, a wide range of additional imaging patterns occur, including leukoencephalopathy, global hypoxic injury, acute demyelinating encephalomyelitis, cytotoxic lesions of the corpus callosum, olfactory bulb involvement, cranial nerve enhancement, and Guillain Barré syndrome. The described central nervous system abnormalities largely represent secondary involvement from immune activation that leads to a prothrombotic state and cytokine storm; evidence for direct neuroinvasion is scant. Comorbidities such as hypertension, complications of prolonged illness and hospitalization, as well as associated supportive treatments, also contribute to the central nervous system involvement in COVID-19. Routine, long-term, neurologic follow-up may be warranted, given emerging evidence of long-term microstructural and functional changes on brain imaging, after COVID-19 recovery.
The Spectrum of Neuroimaging findings on CT and MRI in Adults with Coronavirus Disease (COVID-19)