"Fractures of the skull, as with fractures of any bone, occur when biomechanical stresses exceed the bone's tolerance. The pattern of fracturing depends on the location, direction and kinetic properties of the impact as well as intrinsic features of the skull 2-4."
"arterial dissection, occlusion or rupture"
"arteriovenous fistula (e.g. direct caroticocavernous fistula)"