A concussion is a hit to the brain that causes symptoms to appear fairly quickly, as the brain is shaken violently enough that some brain cells will be damaged, failing to continue to work properly. A sub-concussive impact is any impact below that threshold where the brain is shaken—but not violently enough to cause fairly immediate symptoms.

While it might sound like a sub-concussion is not all that serious, in fact, sub-concussive impacts can add up to brain damage. Soldiers, like professional athletes, are likely to take “hits” to the body on a regular basis that “shake” the brain. Scientists have learned that these sub-concussive impacts, over time, can lead to the following:

• Suppression of brain function;
• Worsening memory and ability to pay attention to tasks, and
• Behavior and mood problems later in life.

In short, these sub-concussive “hits” damage the connections in the brain, making it more difficult for the different areas of the brain to properly communicate. It is likely that a significant percentage of soldiers have experienced these sub-concussive hits and will experience difficulties later in life.

Some of the troops injured in the Al Asad Airbase Ballistic Missile Attack may have experienced these sub-concussive events, while more experienced mild, moderate, or even severe traumatic brain injury. While there were blast injuries that were tended to immediately after the ballistic missile attack, the primary injuries were Iranian ballistic missile-related traumatic brain injury for those in the immediate vicinity.