Tau/P-Tau and Neurocognitive Outcomes in Children

This proposed studies have two specific aims: 1. To investigate the relationship between pre-operative or postoperative blood levels of Tau or P-Tau and neurocognitive outcomes. The working hypothesis is that pre- and postoperative blood Tau/P-Tau levels are higher in participants who develop neurocognitive impairment than those in the participants who do not develop it. The investigators will perform neurocognitive test before the surgery and then at 12 months after the surgery. The investigators will collect pre-operative and postoperative blood and measure Tau/P-Tau levels in the blood. Finally, the association of the changes in the Tau/P-Tau levels and neurocognitive scores will be assessed. More importantly, this Aim will establish an eligible: recruit ratio, retention rates, safety of the protocol, and power calculation, which will provide crucial information to guide better design of future R01 study. 2. To perform the feasibility studies of measuring Tau or P-Tau in urine, feces and saliva of the participants. The working hypothesis is that Tau/P-Tau in urine, feces or saliva of children can be measured. The investigators will use the nanobeam to measure Tau/P-Tau levels before and after the surgery. The investigators will then determine whether urine, feces and saliva can be used for the future studies to develop Tau/P-Tau as the biomarker of anesthesia/surgery-associated neurocognitive impairment in children.