Retrograde amnesia

Retrograde amnesia (RA) is a loss of memory-access to events that occurred, or information that was learned, before an injury or the onset of a disease

. RA is often temporally graded, consistent with Ribot's Law: subjects are more likely to lose recent memories that are closer to the traumatic incident than more remote memories.

Brain structures

The most commonly affected areas are associated with episodic and declarative memory such as the hippocampus, the diencephalon, and the temporal lobes.