Have you ever wondered why intracranial pressure elevation (ICP) is accompanied by systolic spikes in the middle cerebral artery flow velocity signal?
Model simulation shows that the penetration force of arterial acceleration (a brief arterial stiffening at stroke onset) overcomes ICP, whereas later phases of systole (ejection phase) and diastole do not. The video of the model simulation shows how systolic spikes prevail when ICP is gradually increasing.
In the simulation above the intracranial pressure is gradually increased. Notice the simulated waveform of middle cerebral artery flow velocity: blue curve at the right (red curve is simulated arterial blood pressure).