Retrograde Amnesia: Why Doesn’t The Injured Worker Remember The Accident?

After the recent and horrid AMTRAK crash just outside Philadeiphia authorities determined the train was traveling more than twice as fast as the speed limit allowed. Media then focused on the engineer’s claim that he had “no recollection of the crash.” This phenomenon of not being able to remember an accident is not uncommon in  the field of neuropsychology.

In my years of practice working with head injured workers, I have noted that with an altered state of consciousness or a positive loss of consciousness, inevitably, the injured party has no recollection of the actual incident. This phenomenon is called Retrograde Amnesia. It is classified under Post Traumatic Amnesia ( PTA), which I  will discuss in a future post. Retrograde Amnesia is a partial or total loss of the ability to recall events that have occurred during the period immediately preceding the brain’s injury. Retrograde Amnesia targets the most recent memories. Ribot ‘s Law  suggests that  there is a pattern of destroying new memories before older ones because  the neural pathways of the new  memories are  not as strong as the older ones,  which  have been strengthened by years of retrieval. Basically, what happens is that the injured worker loses the memory of and access to the events that occurred immediately before the injury.

Neuropsychologically, here’s how memory storage works, in part. The hippocampus, which deals with memory consolidation (particularly episodic or event memory) is responsible for  transferring information from short-term to long-term storage. It quickly stores new information that it will then transfer to the neocortex for long-term storage. When an event such as a blow to the head results in an altered state of consciousness and/or loss of consciousness, the information about events that have just happened is not immediately transferable – and it may never be. It is as if those events never happened.

Retrograde amnesia usually involves minutes,  sometimes hours,

A study by Cartlidge and Shaw in 1981 showed that the duration of Retrograde Amnesia usually progressively decreases. It is particularly distressing for the injured worker because of the disquieting sense of not knowing exactly what happened. In my clinical experience it is highly unusual that the particular event memories are ever regained totally.

So, what can we take away from this? Well, in retrospect, the media should have cut Brandon Bostian, the train’s engineer, a little slack when he “claimed” to not remember the crash or the events leading up to it. He might or might not have been at fault, we won’t know until the investigation is complete, but he nearly certainly wasn’t lying about his loss of memory. And, by the way, he’s probably not the only person who lived through the crash and has lost memory of it. Second, workers’ compensation claim adjusters should, as part of their training, learn about Retrograde Amnesia. Why? Because, as I’ll describe in a future post, considering this psychological phenomenon early on in a head injury case can significantly shorten the disability and lower its cost.

That’s the sooner, faster, smarter way.