DeeDee249;1704319 "molested by handle" thread and moved to this topic said:Those injuries, while consistant with "shaken baby syndrome", could have come from the severe blow that caused the fracture. A blow that hard would not only fracture the skull, but anything hard enough to knock out a piece of the skull would certainly cause the brain to slam against the skull.
Yes, the blow that displaced her skull could certainly account for much of the brain damage. If we consider the displaced section is toward the middle back of the cranium and if JonBenet's head hit something rather than being hit with a weapon, it doesn't seem likely she would get the type "bruising" indicated on the left and right sides of the brain. Even if she was struck with a weapon, the concussion should most likely appear in the front and back sections of the brain (described as anterior and posterior in the public autopsy).
The "bruising" on the sides of the brain would be consistent with being grabbed by her shirt collar and pushed, shoved, or otherwise "man-handled" into submission. This type action, if done by a forceful adult, would likely leave "shaken-baby syndrome" evidence. It also matches the external damage, i.e. marks on her neck that are not explained by the ligature device. Of course, this part of the damage could also be from someone trying to revive her after she hit her head (as suggested by Solace several weeks ago) or, as you also said, it could be caused from whatever displaced the skull segment but that doesn't seem as likely to me.