The dissociation of anterograde and retrograde amnesia in a patient with herpes encephalitis.

Establishing the precise relationship between anterograde amnesia (AA) and retrograde amnesia (RA) has implications for psychological and neuroanatomical models of memory. Many patients have been described who demonstrate AA in conjunction with RA or who demonstrate AA with little, or no apparent, RA. Intact anterograde memory in conjunction with deficits on tasks of retrograde memory is rarely encountered. In this paper, we describe a young female patient (LD) whose RA is extremely severe when contrasted with her mild to moderate deficits on tasks of verbal anterograde memory. In addition, on tests of episodic and semantic autobiographical memory, LD appeared more impaired in her recall of specific episodes than of factual information about her past. The importance of this dissociation in RA for the episodic-semantic distinction and the possible role of visual imagery in recalling remote episodic events are discussed.