In the past, the military’s approach to diagnosing head injuries was very limited. Military members were only screened for a concussion or brain injury if their head came into contact with a stationary object or if an object hit them in the head. It took years for medical personnel to realize that the force of a blast wave – the rapid increase in air pressure resulting from an explosion – can result in similar brain damage, or even worse. A blast wave causes the skull to flex, where the brain is pushed against one side of the skull, and then rebound back in the other direction. The human brain undergoes a sudden change in intracranial pressure resulting in damage to axonal pathways, which are crucial to a healthy nervous system, and capillaries, which help supply blood to the brain cells. This damage can result in long-term impairment, such as behavioral abnormalities, reduced impulse control, emotional outbursts, violence, and even suicide.
There have been much-needed changes to the helmets troops wear in combat. For many years, soldiers wore Kevlar helmets with webbing systems thought to protect the brain from various types of injury. However, it was found that this style of helmet not only fails to protect the brain, but actually traps a blast wave between the helmet and head in a phenomenon referred to as “under wash.” Improvements to the original design have been made. Helmets are now made to cover more of the back and sides of the head, and foam pads have replaced the webbing to provide a type of seal between the helmet and head. This minimizes potential injury from a blast wave, but still does not prevent it. The Army has also started to insert sensors in soldiers’ helmets to measure impact on the brain after a concussive event such as an explosion. This crucial information is used by medical personnel for further evaluation. The information collected by the sensors also contributes to the advancement of research on TBIs in service members. As of 2013, approximately 27,000 helmet sensors were in use in combat zones and training areas.