Amnesia after Brain Injury
No need for total loss, as portrayed by Hollywood. The American Congress of Rehabilitation Medicine talks about “any loss of memory for events immediately before or after the accident.” The following are different types of amnesia after brain injury.
Retrograde Amnesia after Brain Injury
Loss of memory for events before the accident is called retrograde amnesia, similar to the use of the term retroactive (something that relates back to a time prior to the event).
Anterograde Amnesia after Brain Injury
Loss of memory for events after the accident is called anterograde amnesia or post traumatic amnesia. This also includes problems with new learning.
Amnesia or Loss of Memory May Not Be Consistent or Predictable
“Swiss Cheese Memory”
In all likelihood after a brain injury, there will holes in memory, but no predicting where and when the holes will appear. That is why the term “Swiss Cheese Memory” is used. The location of the memory holes, at any given layer of recollection, may be as difficult to predict as the location of the holes in a slice of Swiss cheese.
Amnesia is perhaps the easiest element to reconstruct. A detailed interview of the survivor and his or her family will often identify the amnesia. Watch for “confabulation,” the brain injured person reconstructing memory, and/or filling in the blanks. This is not done on purpose and is not a sign of dishonesty.
The length of amnesia may be a better indicator of the severity of brain injury than the traditional method of classifying based upon the length of loss of consciousness or LOC. Injuries are regarded as severe if post traumatic amnesia (PTA) or anterograde amnesia, exceeds 24 hours and very severe if the PTA exceeds one week.
NEXT: Focal Neurological Deficits.