Selective loss and preservation of biographical knowledge: implications for representation.

A 54-year-old patient of average intelligence with a severe and enduring loss of old autobiographical memories after herpes simplex type 1 infection is described. She was tested with a comprehensive neuropsychological battery 2 years after the infection. Special emphasis was laid on examining different aspects of retrograde memory. The neurological examination involved MRI and SPECT. Brain damage was found mainly in the right temporofrontal region, but minor left-sided damage to this region seems possible. The patient was in the normal or slightly subnormal range for all tested anterograde memory functions, but manifested severe retrograde memory deficits with respect to episodic old memories and more moderate deficits in tests of general knowledge (semantic old memories). It is concluded that the ecphory of old autobiographical memories relies heavily on an activation of the right lateral temporofrontal junction area, but that probably only some complementary left hemispheric damage to these regions will lead to major and persistent retrograde amnesia. Alternatively, the disconnection between major pre-frontal and posterior cortical regions may provide a basis for retrograde amnesia. Journal Journal of Neurology, Neurosurgery and Psychiatry 1996; 61: 304–10 Neurocase Reference Number: P829 Primary diagnosis of interest Retrograde amnesia Author’s designation of case Not identified Key theoretical issue d Preservation of public remote knowledge in the context of impaired episodic memory d Lateral temporal regions implicated in retrograde amnesia