What term describes the mechanism of injury where the brain rebounds off the skull after an initial impact?

The term that describes the mechanism of injury where the brain rebounds off the skull after an initial impact is “contrecoup.” This occurs when a force is applied to one side of the head, causing the brain to move within the skull and collide with the opposite side. This can result in injury to the brain tissue and structures located on the side away from the impact, leading to potentially serious neurological consequences.

Understanding this mechanism is crucial in the context of traumatic brain injuries, as contrecoup injuries can be just as damaging as the initial impact. For instance, a person who experiences a sudden stop—such as in a car accident—might hit their head on the dashboard, leading to injury at the point of contact and then further injury as the brain strikes the opposite side of the skull.

The other terms relate to different types of injuries. Comminuted refers to a bone fracture that results in multiple pieces, while concussion is a type of mild traumatic brain injury characterized by symptoms such as confusion and light sensitivity. Penetrating refers to injuries where an object breaches the skull and enters the brain. These definitions help in understanding the context and implications of various brain injuries.