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

The VINCI-AD study is an investigator-led, single-centre crossover device study of the NEMOS Cerbomed auricular transcutaneous vagus nerve stimulator (t-VNS) device in participants with diagnosed Mild Cognitive Impairment (MCI). The study will assess the feasibility, safety and tolerability of the study device for the treatment of older adults with MCI. The device contains a small electrode programmed to 8 Hz stimulation, with participant-selected amplitude settings, which delivers a small amount of stimulation to the vagus nerve via the auricular branch of the vagus nerve located in the outer ear. All eligible participants will be enrolled to three visits to the investigation site, wherein they will undergo baseline (no stimulation), active or sham stimulation for 60 minutes during assessments. Participants will act as their own controls with baseline and sham assessments, undertaken 7-10 days apart. The study is single-blinded as the participants will not be aware whether active or sham stimulation is ongoing during respective assessments. Neurocardiovascular assessments will be initially undertaken at each visit, encompassing heart rate variability (HRV) measures, active stand after minimum of 5 minutes lying supine, with associated near-infrared spectroscopy (NIRS) assessments. Given the orthostatic challenge, each participant will be asked to not consume caffeine prior to assessment and to attend at 14:00 for each assessment. Orthostatic challenges are undertaken indoors at 21 degrees centigrade in the research laboratory. Cognitive tests undertaken will encompass a computer-based associative memory task, involving 30 Face-Name association pairs; the Sustained Attention Response to Task (SART) test, spatial navigation via Sea Hero Quest Research App and Repeatable Battery for Assessment of Neuropsychological Status examination. NIRS assessment will be ongoing during cognitive testing. Serum and plasma markers of inflammation including cytokines and chemokines will be taken after each assessment (baseline, active and sham stimulation).