Nonlinear Modeling of the Dynamic Effects of Arterial Pressure and Blood Gas Variations on Cerebral Blood Flow in Healthy Humans

Abstract

Cerebrovascular resistance is controlled by multiple homeostatic mechanisms, which regulate cerebral blood flow (CBF), maintaining it relatively constant despite changes in cerebral perfusion pressure1–2. The regulation of CBF was long viewed as a static phenomenon, whereby the “steady-state†pressure-flow relationship is described by a sigmoidal curve with a wide plateau, suggesting that CBF remains constant despite changes in pressure within certain bounds. However, with the development of Transcranial Doppler (TCD) ultrasonography for the noninvasive, high-temporal resolution measurement of CBF velocity (CBFV), it has been shown that CBFV can vary rapidly in response to variations of systemic arterial blood pressure (ABP) over various time scales3–4.