COVID-Related Leukoencephalopathy: Unusual MRI Features and Comparability to Delayed Post Hypoxic Ischemic Encephalopathy

COVID-19 related leukoencephalopathy can be multifactorial given the systemic effects of the viral disease. We present couple of cases with typical clinico-imaging stigmata of COVID-19 resulting in severe respiratory insufficiency. MR brain imaging revealed confluent diffuse supratentorial white matter T2 hyperintensity with restricted diffusion during the sub-acute course of the disease. The MR imaging pattern of leukoencephalopathy was non-specific but more comparable to delayed post-hypoxic leukoencephalopathy (DPHL) as also previously reported in COVID-19. Interestingly, T2 imaging showed unusual but peculiar finding of "accentuated medullary veins" in the superficial zones. No dural venous sinus thrombosis or micro-hemorrhages were present to explain "dots and stripes" due to dilated medullary veins. The patho-mechanism of this findings is not clear but may possibly be related to demyelination as DPHL has shown to be a demyelinating process. We present a review of COVID-related leukoencephalopathy with discussion on hypoxia-induced demyelinating process with accentuated medullary veins as possible associated marker.