Starling resistors, autoregulation of cerebral perfusion and the pathogenesis of Idiopathic Intracranial Hypertension.

Starling resistors, autoregulation of cerebral perfusion and the pathogenesis of Idiopathic Intracranial Hypertension. Panminerva Med. 2016 Sep 6; Authors: De Simone R, Ranieri A, Bonavita V Abstract Two critical functions for the control of intracranial fluids dynamics are carried on the venous side of the perfusion circuit: the first is the avoidance of cortical veins collapse during the physiological increases of cerebrospinal fluid (CSF) pressure in which they are immersed. The second, is the generation of an abrupt venous pressure drop at the confluence of the cortical veins with the dural sinuses that is required to allow a CSF outflow rate balanced with its production. There is evidence that both of these effects are ensured by a Starling resistor mechanism (a fluid dynamic construct that governs the flow in collapsible tubes exposed to variable external pressure) acting at the confluence of cortical veins in the dural sinus. This implies that, in normal circumstances of perfusion balance, a certain degree of venous collapse physiologically occurs at the distal end of the cortical vein. This is passively modulated by the transmural pressure of the venous wall (i.e. the difference between internal blood pressure and external CSF pressure). The mechanism provides that the blood pressure of the cortical vein upstream the collapsed segment is dynamically maintained a few mmHg higher than the CSF pressure, so as to prevent their co...
Source: Panminerva Medica - Category: Journals (General) Tags: Panminerva Med Source Type: research