Retrograde amnesia

Retrograde amnesia is a form of amnesia where someone will be unable to recall events that occurred before the onset of amnesia. The term is used to categorise patterns of symptoms, rather than to indicate a particular cause or etiology. Both retrograde amnesia and anterograde amnesia can occur together in the same patient, and commonly result from damage to the brain regions most closely associated with episodic/declarative memory: the medial temporal lobes and especially the hippocampus.

Retrograde amnesia is a popular plot element in fiction, in particular in film noir, science fiction, and thriller fiction.