Correlations between blood pressure and brain function
Dariusz Dziubek1, Karolina Dziubek2
Arterial hypertension is a chronic inflammatory process. The brain centre that controls blood pressure is located in the rostral ventrolateral medulla. Chronic diseases of the circulatory system, such as hypertension or heart failure, result in changes in the expression of genes for neurotransmitters and neuromodulators of the brain, which leads to disturbances in the central regulation of homeostasis. Approximately 700–900 mL of blood flows through the brain per minute, which is approximately 15–20% of the cardiac output. Cerebral blood flow in physiological conditions is on average 50 mL/100 g/min and depends on the value of intracranial pressure and the degree of vascular resistance. Maintaining proper blood pressure homeostasis is essential for the brain to function correctly. Central autonomic regulation of blood pressure and the influence of blood pressure on brain function create an inseparable mutual feedback loop. Chronically high blood pressure values lead to irreversible changes in the cerebral vessels and are among the main risk factors for the development of atherosclerosis and stroke. Acute hypertension, as demonstrated in animal models, may lead to cognitive impairment caused by modification of protein transcription due to oxidative stress. Blood pressure values are subject to seasonal and circadian variations, which should be taken into account when planning treatment. This article compiles key information regarding the interdependence between blood pressure values and brain functionality, taking into account the basics of physiology and pathophysiology of the phenomenon and the latest reports from the scientific literature.