RIGHT TEMPOROFRONTAL CORTEX AS CRITICAL LOCUS FOR THE ECPHORY OF OLD EPISODIC MEMORIES

A 54 year old patient of average intelligence with a severe and enduri ng loss of old autobiographical memories after herpes simplex type 1 i nfection is described. She was tested with a comprehensive neuropsycho logical battery two years after the infection. Special emphasis was la id on examining different aspects of retrograde memory. The neurologic al examination involved MRI and SPECT. Brain damage was found mainly i n the right temporofrontal region, but minor left sided damage to this region seems possible. The patient was in the normal or slightly subn ormal range for all tested anterograde memory functions, but manifeste d severe retrograde memory deficits with respect to episodic old memor ies and more moderate deficits in tests of general knowledge (semantic old memories). It is concluded that the ecphory of old autobiographic al memories relies heavily on an activation of the right lateral tempo rofrontal junction area, but that probably only some complementary lef t hemispheric damage to these regions will lead to major and persisten t retrograde amnesia. Alternatively, the disconnection between major p refrontal and posterior cortical regions may provide a basis for retro grade amnesia.