Non-invasive brain stimulation and neurovascular mechanisms of post-stroke cognitive impairment - PROJECT SUMMARY Stroke is the leading cause of death and long-term disability in the United States. Up to 60% of stroke survivors develop post-stroke cognitive impairment (PSCI) in the first year after stroke. PSCI is a significant public health problem, as it can lead to a loss of independence, reduced quality of life, and increased healthcare costs. Despite its high prevalence, there is no established treatment for PSCI. New and innovative treatments are needed to improve cognitive function in stroke survivors with PSCI. Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that has shown promise in improving cognitive function in a variety of conditions, including stroke. tDCS works by delivering a weak electrical current through the scalp. This current can modulate the activity of neurons in the brain. While tDCS has been shown to improve cognitive function in stroke survivors, the mechanism by which this effect is mediated remains understudied. Although most existing studies have primarily focused on the neuronal effects of tDCS, brain stimulation has a broad effect on a variety of brain cells and several studies report that tDCS can increase resting cerebral blood flow both in animals and healthy individuals. However, whether tDCS is capable of modulating hemodynamic responses in PSCI is significantly understudied. This project will investigate the potential of tDCS as a therapeutic intervention to improve neurovascular coupling (NVC) and cognitive function in stroke survivors with PSCI. NVC is a critical mechanism that allows the brain to match blood flow to metabolic demand. Current clinical evidence indicates that NVC impairment is associated with PSCI. In Aim 1, I will comprehensively evaluate NVC responses in stroke survivors with and without cognitive impairment, and compare their NVC responses to healthy sex and age matched controls. In Aim 2, I will conduct a prospective sham-controlled clinical trial to determine if active tDCS leads to a significant improvement of NVC responses in stroke survivors and whether these changes are associated with improvements in cognitive performance. This project has the potential to develop a novel and effective treatment for PSCI. By using a multimodal approach (simultaneous fNIRS-EEG), this proposal aims to investigate a potentially reversible mechanism of cognitive decline following stroke and contributes to the advancement of neuroscience research in vascular cognitive impairment.
