Cerebral Palsy maybe/maybe not

PVL four limb involvement is unlike that seen in total body involvement as the kind OF neurological injury is different and where it resides is different.

Recap: Damage distribution can be by blood vessel coverage area (clot or torn). It can be by areas with less total access to bigger vessels (PVL) or by insufficient O2 for cells that are doing high metabolic work. There are chemical causes as well. Very hard to detect, but bacteria inside the womb but outside the embryonic sac can secrete bacterial waste which is toxic. Olne twin can need more O2 than the other (is bigger). Shared placentas can favor one over the other and also add premature issues to flow issues. The point?

Injury isn’t just a ‘where’. It is also a ‘why’. 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 still deliver O2 and survive low pressure while other places with less extra vascularity suffer. Why low flow? Born too soon. The heart has a big hole in it (septal ‘defect’) which is there for placenta based flow as is the aorta shunt (ductus arteriosus). The

placenta is the fetal lung substitute These shunts arolund the lung under construction detour will get a mechanism to quickly narrow & close up when birth starts, but not yet. The one wide arcing area that is at highest flow pressure risk is adjacent the ventricles (= purple in right illustration seen from behind looking toward mid-line).