Perioperative non-invasive neuromodulation for delirium and cognitive recovery: from preclinical evidence to clinical translation

Perioperative neurocognitive disorders (PND) are a challenge for patients to accelerate postoperative recovery, and exploring more effective interventions can help reduce long-term cognitive dysfunction. Non-invasive neuromodulation (NIN) has shown potential in improving postoperative cognitive function and reducing delirium. This review aims to summarize the impact of NIN technology on the incidence of PND, including preclinical studies and clinical translational trials. Neuromodulation techniques include transcranial direct current stimulation (tDCS), repetitive transcranial magnetic stimulation (rTMS), Theta burst stimulation (TBS), transcranial alternating current stimulation (tACS), transcranial ultrasound stimulation (tUS), temporal interference stimulation (TIS), transcutaneous auricular vagus nerve stimulation (taVNS), transcranial photobiomodulation (tPBM), and 40-Hz Gamma entrainment using sensory stimuli (GENUS). Preliminary evidence suggests that NIN technology may have benefits in improving delirium and cognitive recovery in surgical patients. Further research may need to pay more attention to the technical parameters of the device, stimulation protocols, and the global effects on brain network connectivity. Strict clinical trials, adoption of multimodal brain network monitoring, and optimization of technical solutions are still needed in the future.