View clinical trials related to Cerebral Blood Flow.
Filter by:This study plans to learn more about how alcohol and its metabolite, acetate, affect the brain.
This study is designed to test whether treatment with kudzu extract will increase the rate at which alcohol enters the brain as measured by rapid proton magnetic resonance spectroscopy (1H-MRS).
Berry fruits are widely recognised as natural functional food products. They contain several different phytochemicals which have potential to modulate human health and wellbeing. There is however some debate regarding the mechanisms driving their health promoting properties. Despite the wide health promoting properties of fruit extracts reported in the literature, considerable interest over the past decade has primarily been focused on their roles in reducing risk factors associated with cancer and heart disease. Consequently, there remains a paucity of actual scientific information on their role in modulating brain functions, such as mood, learning and memory, any decrements of which have very negative impacts on the quality of life. Fruit phytochemicals from other sources have been shown to mediate both peripheral and cerebral blood flow. However, a modulation of cerebral blood flow has not been shown with berries as yet. Cerebral blood flow must be maintained to ensure a constant delivery of oxygen and glucose as well as the removal of waste products. The modulation of cerebral blood flow via supplementation of berry polyphenols could therefore be a potential way to positively modulate human cognitive behavior. The link between acute increases in cerebral blood flow and increased cognition is currently a little weak but it could give a good platform for long term behavioral and health benefits via increased cerebral/peripheral blood flow and decreased MAO-B activity. The aims of the study are therefore to investigate the impact of the berry extract on digital volume pulse, blood pressure and cerebral blood flow.
Dietary intake of omega-3 polyunsaturated fatty acids (n-3 PUFAs) is inversely associated with cognitive decline and dementia (e.g. Kalmijn et al. 2004, Heude et al. 2003, Morris et al. 2005, Dullemeijer et al. 2009). Recently, the effects of supplemental docosahexaenoic acid (DHA) on behavioural outcomes in older adults has been explored, however two trials addressing this issue have published conflicting results regarding the efficacy of DHA supplementation, with one reporting a benefit of treatment on cognitive performance (Yurko-Mauro et al. 2010), while the other did not (Dangour et al. 2010). One area of research that has yet to be explored in this cohort is the effects of n-3 PUFAs on brain function in physiological terms. It is also possible that n-3 PUFAs, in combination with other compounds, may be more beneficial than treatment with n-3 PUFAs in isolation. The current study will explore several separate hypotheses within the same cohort. These are that Efalex Active 50+ may have a beneficial effect on: - Cognitive performance - Mental fatigue in response to cognitively demanding tasks - Self-reported mood/well-being - Task-related cerebral blood flow response The proposed study therefore has two aims; the primary aim is to evaluate the cognitive and mood/well-being effects of Efalex Active 50+, a dietary supplement containing a number of potentially cognition enhancing components including DHA, phosphatidylserine, vitamin B12, folic acid and Ginkgo biloba, compared with placebo in a sample of older adults aged 50-70 years (Cognitive Study). The second is to evaluate the cerebral haemodynamic effects of the same treatment formulation in a sample drawn from the same population, with the addition of a third DHA-only arm (Hemodynamics Study). The intervention period will be 6 months.
DHA has previously been shown to increase regional cerebral blood flow response to tactile stimulation in aged monkeys; modulation of cerebral blood flow in humans has yet to be demonstrated. Given that the brain relies on a constant supply of blood-borne metabolic substrates (e.g. glucose, oxygen), increasing regional cerebral blood flow may also have an impact on cognitive function. The current study aims to investigate the effects of two doses of DHA-rich fish oil on task-related cerebral hemodynamic response and cognitive performance in healthy adults.
Preterm infants often need peripheral artery catheters for invasive blood pressure recording and to facilitate blood sampling. Near infrared spectroscopy is a method to evaluate cerebral oxygenation and as well as cerebral blood flow. Sampling procedures with identical sampling volumes are performed at a short (40 seconds) and a long (70 seconds) time intervall while changes of cerebral oxygenation are measured. The investigators hypothesise that slower sampling decrease changes in cerebral blood flow.