TNF and Cognitive impairment: Studies have shown that the sevoflurane induces neuroinflammation by upregulating the expression of inflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin- (IL-) 1β and resulted in the increase of Aβ expression, hyperphosphorylation of tau, neuronal apoptosis, and subsequent cognitive impairment [9–11].