2 Clinical Trials for Various Conditions
Prolonged sitting may pose a public health risk through its effects on the cardiovascular system, and may lead to impaired whole-body cardiovascular health, which includes both vascular and cerebrovascular function. These effects may interact with other environmental variables, such as stress. However, no study has investigated the combined effect of a mental stressor and prolonged sitting on vascular and cerebrovascular function. The combined effect of prolonged sitting and mental stress may lead to an exacerbated effect on vascular, cerebrovascular, and executive function. The investigators hypothesize that mental stress with the addition of prolonged sitting \[PS\] will result in a greater increase in peripheral, central and cerebral arterial stiffness and elicit a decrease in cerebral perfusion, total blood flow to the brain, middle cerebral artery velocity and executive function, compared to mental stress without prolonged sitting \[CON\]. The findings from this study may result in a public health message regarding sedentary behavior and stress, and will help elucidate the mechanisms behind acute vascular, cerebrovascular, and cognitive dysfunction during prolonged sitting.
Patients with blockage of the blood vessels that supply blood to the back of the brain, known as vertebrobasilar disease (VBD), are at risk of having a stroke or temporary symptoms of a stroke known as transient ischemic attack (TIA). The risk of repeated stroke associated with VBD may be affected by several risk factors, including the degree to which the blockage reduces the blood flow to the brain. Patients with VBD have different levels of blockage ranging from partial blockage to complete blockage, which can affect the blood flow to the brain by variable amounts. The purpose of this research is to determine if patients with symptomatic VBD who demonstrate low blood flow to the back of the brain on magnetic resonance (MR)imaging are at higher risk of developing another stroke or TIA than patients with normal blood flow.