Fig. 2

Vasodilation and vasoconstriction cascade in the cerebral vasculature. This cascade model was first described by Rosner in the 1990s (see references 22, 23). A cascade of this type is often trigged by changes in CPP. Any step in the cascade, however, can be triggered as the starting point. There are many triggering factors such as dehydration, vascular volume, systemic metabolism, CMRO₂, blood viscosity, systemic oxygen delivery, PaCO₂, or certain pharmacologic agents. SAP systemic arterial pressure, CPP cerebral perfusion pressure, ICP intracranial pressure, CBV cerebral blood volume, CMRO ₂ cerebral metabolic rate for oxygen