Effect of preoperative transcranial direct current stimulation on postoperative delirium in elderly patients following laparoscopic surgery.

BACKGROUND: Postoperative delirium (POD), an acute neuropsychiatric complication in elderly surgical patients, manifests as attention and cognitive disturbances that may last 24-72 hours after surgery, potentially progressing to dementia. Transcranial direct current stimulation (tDCS), a non-invasive neuromodulation technique, enhances cortical excitability and cognitive function by modulating brain networks and synaptic plasticity. Elderly patients undergoing major laparoscopic surgery face elevated POD risks due to prolonged anesthesia and pneumoperitoneum-induced cerebral hypoperfusion. This study investigates whether pre-anesthesia tDCS can reduce POD incidence in this population. AIM: To investigate the effect of preoperative tDCS on reducing the incidence of POD in elderly patients undergoing major laparoscopic surgery. METHODS: In this study, we enrolled 220 elderly patients who underwent major laparoscopic surgery between April 2024 and December 2024. Patients were randomly assigned to the active-tDCS (group A) and sham-tDCS (group S) groups. A single session of tDCS or sham stimulation was administered 30 minutes before anesthesia induction. The primary outcome was the incidence of POD during within 3 days postoperatively. RESULTS: A total of 201 patients were included in the final analysis, with 100 patients in group A and 101 in group S. The incidence of POD within 3 days postoperatively was 7.0% in group A, which was significantly lower than 22.8% in group S. On postoperative day 1, the Self-Rating Anxiety Scale and Self-Rating Depression Scale scores significantly differed between the two groups, but the pain scores showed no significant difference. CONCLUSION: A single session of preoperative tDCS can reduce the incidence of POD in elderly patients undergoing major laparoscopic surgery and can also reduce postoperative anxiety and depression in these patients.