Blast injuries in TBI are caused by?

• A. Slow mechanical changes
• B. Fast-moving pressure waves that can affect the skull and brain parenchyma
• C. Bleeding within ventricles
• D. Chronic scalp injuries

Answer: (B)

Blast-related brain injury comes from the rapid overpressure wave produced by an explosion. This fast-moving shock wave travels through the skull and into brain tissue, causing immediate mechanical disruption and vascular injury. The energy transfer can produce contusions, hemorrhages, and diffuse axonal injury, even when external head damage is minimal. This primary blast mechanism is the main driver of TBI in blasts, differentiating it from injuries caused by shrapnel or blunt trauma, and from chronic scalp injuries that aren’t the source of brain injury in blasts.