Vasodilatory Cascade: ICP Response to CPP Level and Reduction Rate

Abstract

Previous work has suggested that CSF pressure waves are in large part the result of an unstable blood pressure acting upon a more or less intact autoregulating cerebral vascular bed in the face of pathologically increased ICP and/or increased brain stiffness. The “vasodilatory cascade” model for CSF pressure wave generation was subsequently developed. This model suggests decrements in CPP will stimulate vasodilatation which will tend to increase cerebral blood volume (CBV). The increase will increase ICP which will further reduce CPP. Unless there is a response in the systemic arterial blood pressure (SABP) side of the CPP equation, the cycle will continue leading to more vasodilatation, increased CBV and a further increase in ICP which will further reduce CPP until vasodilatation is maximal. We have undertaken a series of experiments to further validate this ICP wave model.