IL10 and Posterior Leukoencephalopathy Syndrome: COVID-19 disease severity has been directly linked with increased serum levels of IL-6 and IL-10 [63], and despite the hypothesis that these cytokines result in the cytokine storm that in itself causes PRES, it is interesting to note that an IL-6 receptor inhibitor i.e. tocilizumab has been linked with an increased risk for PRES [64,65].