Cerebral Palsy maybe/maybe not

PVL is a consequence of insufficient flow pressure AND prematurity. Why? Well, the fetal brain surface is covered with many many arteries & veins not seen in the full term baby. The basic brain is being built. If blood pressure drops & flow of blood slows then the brain surface is kind of protected by that abundance of vessels and can survive low pressure while other places suffer. Why low flow? Born too soon. The heart has a big hole in it for placenta based flow as does the aorta (ductus arteriosus). These will get a mechanism to quickly narrow & close up when birth starts, but not now, not yet.

The one wide arcing area that is at highest risk is adjacent the ventricles (= blue in right illustration).

That is shore front property. There is no blood flow crossing that ocean. Here all the vessels are kind of dead ends. Low pressure leaves this tissue wanting. Spotty bits undergo necrosis (croak) and at autopsy look like white (leuko) soft spots (malacia) in the peri ventricular tissues, hence PVL. In horizontal cross section (exempli gratia in MRI) this zone looks like a boomerang with the apex pointing to the mid-line.

This apex has the least flow and so determines the most frequent consequences. The foot- leg-hip tracts radiate away from this center. Trunk to hands are further from this arcing zone center. When you see hand involvement, the spread isn’t just longer along the boomerang region. The boomerang damage itself is thicker, especially spreading out at the apex. This then approaches hand areas and ‘ganglia’ which bring in some dystonic qualities – especially in the hands – less so in the legs. The cortex is still spared unless those extra vessels rupture (hemorrhage).