MoA: bruise of the cortical surface with hemorrhage from a torn vessel into the cortex Contre-Coup: rotational shear (anterior and middle skull bases have rigid sphenoid wings and petrous ridges). Rotation causes the frontal and temporal cortices to sweep across these structures and slow down, shearing the axons and vessels Coup contusions: underlying brain impacts skull. Loc: convexities. Epi: less common and less severe. The bones are usually intact.
Var: children - uncommon b/c softer unmyelinated brain with smoother skull bases, more pliable skull. 20% of contusions develop delayed hemorrhages