Plasma levels of NSE and Tau protein have been associated with brain injury and delirium.23,24 Neuron-specific enolase is a promising peripheral blood marker of brain injury as it is a cytosolic enzyme primarily expressed in neurons and neuroendocrine cells, with a high concentration in the brain.25 Neuron-specific enolase has demonstrated value in assessing the severity of brain injury and early prognosis following traumatic brain injury,26 cardiac arrest,27 and sepsis.28 This evidence concerns the gene MAPT and delirium.