No one is certain what really causes primary explosive blast traumatic brain injury (bTBI), according to doctors. Clearly, the “cause” is the explosion and the mechanism by which it works is the interaction of explosive force upon the human body, but this does not medically explain everything that occurs.
There are primary and secondary injury mechanisms when it comes to trauma. Primary injury mechanisms can be attributed directly to the cause of the injury, like laceration from a cut. Secondary injuries are physiological responses, like bleeding or bruising. When it comes to bTBI, doctors have learned, there is probably more than one primary injury mechanism involved. Hospitals in the Bronx and Brooklyn are studying this.
The blast produced by an explosive device travels through a medium like air or water in a wave of pressure. Basically, a great deal of energy is chemically produced. Mechanical, thermal, and electromagnetic energy is transferred into the surrounding medium, and into anyone who happens to be in the blast radius.
A detonation is especially deadly because the speed of the pressure waves can sometimes exceed the wave speed of the host medium and become shockwaves – the force of the blast breaking the sound barrier. An explosion such as this will lead with a shockwave, which alone has the power to move and deform things in its path, such as the head of its victim. The speed at which this occurs, as well as the immense pressure, is quite likely to result in brain injury, doctors have learned.