Systolic excess pressures strain the arterial and arteriolar walls and raise the risk of vascular ruptures.

Diastolic excess pressures can be caught up by contraction of the arterioles - otherwise they might raise the risk of a diffuse cerebral edema / brain swelling

Franz Schelling

Beautifully put......peak pressures are the risk factors for sudden bleeds,and just as variability is linked to stroke,so also is stroke linked to severe variability post stroke.

It's a pity the effects of pressure surges reaching the brain via veins are so little known (CCSVI criterion two is still

ill-defined and neglected)