Low-frequency Electrical Stimulation for Cognitive Enhancement in Atrial Fibrillation

Cognitive function in patients with atrial fibrillation (AF) is often impaired due to the complex influence of various factors (cerebral hypoperfusion, neurodegeneration, microemboli, hypertension, chronic inflammation). This leads to impairment of cognitive functions, including attention, memory, executive functions, and speed of information processing. The search for affordable and safe methods to maintain or improve cognitive function in this group of people is an urgent task of modern medicine. One of the promising approaches is percutaneous low-frequency electrical stimulation of the auricular branch of the vagus nerve (transcutaneous Vagus Nerve Stimulation - tVNS). The auricular (auricular) branch of the vagus nerve is a peripheral branch of the vagus nerve innervating the skin of the auricle in the area of the tragus and the inner part of the external auditory canal. The tVNS engages the sensory fibres of the vagus nerve and thus mimics the sensory input to the brainstem, forming the so-called auriculo-vagal afferent pathway. Since these fibres project directly to the nucleus of the solitary pathway (solitary tract), which, in turn, has direct and indirect projections to the nuclei providing noradrenergic, endorphinergic and serotoninergic fibres in various parts of the brain regulating systemic indices of cardiovascular, respiratory and immunological functions, the organism's response to stimulation of the auricular branch of the vagus nerve is systemic in nature. Stimulation of this nerve can modulate central nervous system (CNS) activity, affecting processes related to memory, attention and emotional state. Mechanisms of action of tVNS include modulation of parasympathetic activity, enhancement of neuroplasticity through increased expression of neurotrophic factors (e.g., BDNF), improvement of cerebral blood circulation, and regulation of neuroinflammation (reduction of proinflammatory cytokines).