Our next lesson on the topic “The Evolution of Our Understanding of Concussion, otherwise Called Mild Traumatic Brain Injury,” is the role that adrenaline plays in masking the most reliable marker for brain injury, that of Post Traumatic Amnesia. The video on this topic is found at http://www.youtube.com/profile?user=braininjuryattorney#p/u/9/N0K2K-lqW18
When a concussed person does find his or her way to the Emergency Room, the first thing that typically gets asked is what do you remember of what happened. The second was did you get knocked out. Both questions are seriously flawed in methodology. Starting with the second, if you presume that someone who is knocked out will have amnesia of the event, how can you ask them what happened to them at a time they were amnestic? We would hope that most experienced ER doctors see the inherent conflict in relying on the answer to such a question from the concussed person.
The more subtle but more significant problem is assuming that because someone has memory of an event, that means they weren’t concussed in the event. This is simply not true and it ignores the well recognized principle that concussed individuals can have islands of memory during otherwise periods of significant amnesia. Amnesia is not a total loss of memory, it is a loss of any period of memory. The islands of memory a concussed person will most likely remember are those things where adrenaline played the greatest role, such as the accident itself. If you have ever been a car wreck that you do remember, especially a serious car wreck, it is something you will remember for the rest of your life. I have been in two serious wrecks and I remember exquisite details of what I was doing just before and in the hours after the wreck. One of those wrecks was in 1975 and the other in 1993. I even remember the date and hour of the 1993 wreck.
My brain remembers them best because they were most important to me. It also remembers them best because they were the most scary. What I don’t remember about the more serious of those accidents, is the ambulance ride. And I should because I was in pain and strapped to a board. In 1975 if I could walk and talk in an Emergency Room and didn’t have any broken bones, that was all they were concerned with. I was discharged home. No one ever asked me a single question about amnesia.
Our concern about concussions has improved dramatically since 1975 but the inquiry with respect to the most likely period of post traumatic amnesia, the period from 5 minutes post accident to 48 hours post accident, is still largely ignored. Since amnesia is the single most reliable symptom in the diagnosis of concussion, that needs to change.