%0 Journal Article
%T The pulsating brain: A review of experimental and clinical studies of intracranial pulsatility
%A Mark E Wagshul
%A Per K Eide
%A Joseph R Madsen
%J Fluids and Barriers of the CNS
%D 2011
%I BioMed Central
%R 10.1186/2045-8118-8-5
%X Numerous homeostatic processes in the brain, such as cerebral blood flow and maintenance of interstitial fluid equilibrium, depend critically on the regulation of intracranial pressure (ICP) and fluid flow. While it is the mean pressure and flow which are most important in these processes, there are also systematic variations in pressure and flow which can play an important part in homeostasis. In the brain, the largest of these variations is due to the variation in blood pressure over the cardiac cycle, henceforth referred to as cardiac pulsatility. Other pulsatile variations, such as respiratory and vasomotor induced oscillations, do affect pressure and flow over time but have less of an effect compared to cardiac-induced variations. (Note: For the remainder of this review article, we will consider cardiac-induced pulsatility only, and refer to this simply as pulsatility). How changes in pulsatile pressure and flow in the brain might affect disease development and progression is a question of recent interest. In particular, in diseases such as hydrocephalus (HC) and traumatic brain injury (TBI) where changes in the biomechanical properties of the brain can lead to marked changes in pressure and flow dynamics, the role of pulsations is a potentially important one. In this article, we will review the study of cardiac-induced pulsatility over the last sixty years by looking at a) the key elements of the pulsatile waveform, b) measurement and analysis methods for pressure and flow pulsatility in the brain, c) an historical review of intracranial pulsatility and how it has led to an improved understanding of intracranial physiology, and finally, d) some speculation about where pulsatility research might take us in improving medical diagnosis and treatment.The contractile variations in cardiac output have two distinct effects on intracranial dynamics, temporal changes in pressure and temporal changes in flow within the brain. While pressure and flow are related physical
%U http://www.fluidsbarrierscns.com/content/8/1/5