Post-traumatic retrograde amnesia with selective impairment of autobiographical memory.

A selective, temporally limited retrograde amnesia, confined to autobiographical memory, was the only sequela of a "minor" head trauma in two young men. The retrograde memory gap covered about one year of life before the trauma and persisted for several months, without any anterograde deficit or other cognitive disturbances. This unusual pattern of retrograde amnesia deserves close consideration and points to the dissociation of memory subsystems and mechanisms.