Perioperative Neurocognitive Disorder

This prospective observational cohort study aims to determine the incidence of early postoperative cognitive dysfunction (POCD) in patients undergoing major gynecological surgery. Cognitive function will be assessed using the Montreal Cognitive Assessment (MoCA) preoperatively and on postoperative day 3. POCD will be defined as a ≥20% relative decline or ≥2-point decrease in MoCA score. The study will also evaluate the association between POCD and perioperative clinical, surgical, and inflammatory parameters.

Perioperative neurocognitive disorder (PND) is one of the most common postoperative complications among elderly patients. However, the mechanism and targeted intervention of PND remains unclear. Our previous clinical studies demonstrated the association between olfactory impairment and PND. Moreover, our translational studies showed that anesthesia/surgery induced olfactory impairment and caused cognitive impairment in mice and olfactory enrichment could prevent the anesthesia/surgery-induced cognitive impairment. However, there was no clinical investigation to determine whether olfactory enrichment can mitigate PND in elderly patients. Therefore, we propose determining whether olfactory enrichment can prevent and/or treat PND in elderly patients.

The goal of this clinical trial is to learn if quantitative measurement of brain and neurofeedback intervention techniques works to prevent perioperative neurocognitive deficits in elderly oncology patients who are to undergo elective major surgery. The main questions it aims to answer are: * Can neurofeedback intervention training reduce the incidence of postoperative delirium in elderly oncology patients? Researchers will compare the incidence of postoperative delirium in elderly oncology patients after training in neurofeedback intervention with those after living a normal life, to see if training in neurofeedback intervention before surgery is effective in preventing the development of postoperative delirium. Participants will: * Take neurocognitive feedback intervention training for 14 days prior to surgery (recommended to be used for at least 1 hour per day for a cumulative preoperative use of 14 hours). * Received preoperative and postoperative assessments of cognitive function by a third-party researcher, as well as daily delirium assessments for 7 days postoperatively. * The subjects in the control group lived a normal life every day before the operation, and the rest of the measures were the same as those in the intervention group.