The Pathophysiology of Concussive Brain Injury.

Concussion is a complex brain injury affecting neurons and nonneuronal cells such as astrocytes, oligodendrocytes, microglia, and endothelial cells, leading to acute neurometabolic disturbances such as ionic imbalance and energy crisis. Beyond metabolism, these cellular responses may drive inflammation, blood-brain barrier disruption, neuroplasticity, glymphatic dysfunction, and neurodegeneration. Recognizing biological vulnerability and knowledge regarding repeat concussions has shaped protocols to prevent premature return to activity and reduce further injury risk. The concept of concussion and postconcussion endotypes, linking persistent symptoms to specific biological mechanisms, guides targeted diagnosis and treatment. Ongoing research into biomarkers and mechanisms aims to improve prognostication and develop personalized treatments for recovery.