amnesia is a form of amnesia resulting from brain injury in
which the individual loses memories for the time period just
prior to the injury. This time period may stretch from a few
minutes to several years, and typically it is worst for event
which occurred just before the injury.
Very rarely, there have been reported cases
in which an individual sustains pure retrograde amnesia as
a result of a physical brain injury. More often, retrograde
amnesia occurs in an individual who also has anterograde
amnesia. In this case, the individual will have near total
loss of memory for events occurring after the injury, and
some loss of memory for events which occurred before the injury.
by Catherine E. Myers. Copyright © 2006 Memory Loss and the Brain