Mechanical nervous system trauma in neonates mainly encompasses blunt impact injury and rotational acceleration/deceleration injury, whether accidental (such as in falls from height or motor vehicle collisions) or nonaccidental (i.e., at the hands of another). The distinction between accidental and nonaccidental patterns of injury is the crux of the issue in examining a deceased infant with clinical or autopsy evidence of trauma, and will be the focus of this chapter. Penetrating projectile and sharp force injury to the brain and spinal cord are sufficiently rare as to be outside the scope of this discussion. Likewise, deaths due to suffocation, drowning, and arson are not covered here, in part because neuropathologic changes are not specific (see Table 65.1).