Background
Cognitive Impairment, cognitive impairment, epilepsy, MCI, dementia, depression
ORTHOSTATIC HYPOTENSION, EPILEPSY, ADVERSE EVENTS, CLINICAL SYNDROME, SECONDARY, EXTERNAL EAR
Mild Cognitive Impairment (MCI) is a clinical syndrome characterised by cognitive impairment and deficits on neuropsychological testing, with intact activities of daily living [Vagus Nerve Stimulation (VNS) involves electrically stimulating the vagus nerve (VN) either directly using implanted VNS (iVNS) devices to directly stimulate the cervical VN or using novel transcutaneous VNS (tVNS) devices. Importantly, tVNS devices are portable, handheld, relatively inexpensive and do not require surgery for implantation. tVNS devices pulse electricity gently through the skin in specific areas (such as the cymba conchae of the external ear) which have extensive VN afferent branches [Improved cognition has been noted in populations treated with iVNS for epilepsy and depression since its approval by the FDA [Older adults with MCI and dementia are at increased risk for Neuro-Cardiovascular Instability (NCVI) and Orthostatic Hypotension (OH) [Vagally-mediated transient reductions cerebral perfusion in those with MCI could be deleterious, as those with MCI have reduced cerebral blood flow compared to Cognitively Unimpaired (CU) individuals at baseline [Oxygenation of cerebral tissue can be noninvasively measures using tools such as NIRS devices. NIRS devices project near-infrared light into underlying tissue (such as cerebral cortical tissue) and measures the backscatter of this light using detectors. Based on the amount of backscatter, the concentration of oxygenated haemoglobin and deoxygenated haemoglobin can be determined and from this information the Tissue Saturation Index (TSI; a measure of tissue oxygenation) can be determined [The Vagus Nerve Stimulation in Mild Cognitive Impairment (VINCI-AD) study will examine the use of an easy-to-use, tVNS device in MCI. VINCI-AD will determine the safety (adverse events ascertainment, peripheral and central haemodynamic responses to active stand) and feasibility of tVNS as a potential treatment in older adults with MCI. Pre-specified exploratory secondary analysis will assess the impact of acute tVNS on cognitive function (namely associative memory, spatial memory, inhibitory control, language and working memory) to provide potential effect size estimates to inform future clinical trials of tVNS in MCI.