Bridging veins and autopsy findings in abusive head trauma.

Bridging veins are crucial for the venous drainage of the brain. They run as short and straight bridges between the brain surface and the superior sagittal sinus in the subdural compartment. Subdural bleeding is a marker for a traumatic mechanism (i.e., acceleration/deceleration, rotational and shearing forces due to violent shaking) causing rupture of the bridging veins. Demonstration of bridging vein rupture allows the unequivocal diagnosis of a traumatic mechanism and should therefore be a routine part of the postmortem in cases of subdural hemorrhage.