What characterizes closed head injuries?

Closed head injuries are characterized by blunt trauma that occurs without penetration of the dura mater, which is the outermost layer of the meninges protecting the brain. This type of injury typically results from impacts such as falls, collisions, or assaults, where the skull is impacted but the protective membranes surrounding the brain remain intact.

The integrity of the dura mater means that there is no direct exposure of the brain tissue to the external environment. Consequently, this distinction is vital as it affects the treatment approach and potential complications associated with the injury. Closed head injuries can lead to various complications such as concussions, contusions, or intracranial hemorrhages, but they do so without breaking the protective barrier of the skull and meninges.

The other options describe scenarios that either do not fit the definition of a closed head injury or address conditions related to open head injuries, where there is penetration or significant trauma that compromises the dura mater.