Pathogenesis (development of disease)
Violence acting on the skull causes both primary and secondary damage. In grade 1 traumatic brain injury (TBI), there are usually no detectable changes in the brain.
From grade 2, there is tissue injury, hemorrhage, and/or perifocal (“located around a focus of disease”) edema (“swelling” or “water retention”) formation, which causes an increase in intracranial pressure due to limited intracranial (“located in the skull“) space. Consequently, there is a reduction in cerebral perfusion pressure and thus cerebral blood flow. In turn, the cerebral reduced perfusion below the ischemic threshold (pressure prevents perfusion of the tissue) leads to further ischemic lesions (“injuries”), which result in an increase in the size of the contusionThe contusio may occur at the site of the injury (coup) or on the side opposite the injury (contrecoup) (cortical contusion foci).
It is possible that thrombus formation (formation of blood clots) in the cerebral microcirculation (exchange of substances in the smallest blood vessels) is important for secondary brain injury, in that it leads to pericontusional ischemia (reduced blood flow or a complete loss of blood flow to the tissue). This could perhaps be stopped by inhibiting blood clotting factor XII.
Etiology (Causes)
- Head trauma (so-called shaken baby).
- Falls (52.5%)
- Traffic accidents (26.3%) – increase also due to e-scooters.
- Acts of violence (14, 2 %)
- Sports accidents (6.3%); among adolescents, 20-50% of cases of mild TBI; sports at risk: ice hockey, soccer, basketball, baseball
- Accident, unspecified
(Percentages).