VINCI-AD: An Investigation of Transcutaneous Vagus Nerve Stimulation in Mild Cognitive Impairment.

The VINCI-AD study will investigate the impact of non-invasive vagus nerve stimulation (VNS) on memory in participants with existing mild memory impairment. VNS is a safe, existing treatment, licensed in epilepsy and depression. Until recently, stimulating the vagus nerve involved an operation (invasive VNS) but we can now perform VNS by stimulating a nerve in the outer ear with a very gentle current using a small earpiece, called transcutaneous vagus nerve stimulation (t-VNS). Previous studies have indicated that invasive VNS may improve memory in people with no cognitive issues or with dementia. No study has examined the use of t-VNS in people with diagnosed mild memory issues. The main aim of this study is to assess the feasibility of using t-VNS in participants with Mild Cognitive Impairment (MCI). Other objectives include: 1) Determining the optimal stimulation settings to improve memory; 2) Assessment of safety and tolerability of VNS in participants with memory impairment ; 3) Exploration of impact of non-invasive VNS on brain oxygenation via near-infrared spectroscopy (NIRS): 4) Assessment of impact of VNS on blood markers of inflammation: 5) Assessment of impact of VNS on heart rate variability (HRV) and orthostatic stress in participants with memory impairment. The study will enroll participants via the memory assessment service who have been diagnosed with MCI. The study will enroll 40 participants. All eligible participants will undergo three assessments; one as a baseline assessment of neurocardiovascular health, baseline cognitive tests and baseline blood tests. They will then return for two further visits, one while undergoing active stimulation (active t-VNS) and one while undergoing sham stimulation (sham t-VNS).