RETROGRADE-AMNESIA AFTER TRAUMATIC INJURY OF THE FRONTOTEMPORAL CORTEX

An industrial manager had severe retrograde and variable but usually mild anterograde amnesia four years after a head injury. MRI showed damage of both temporal poles and the lateral portion of the -right prefrontal cortex. The prefrontal and temporal cortical damage on the right side extended deeply into the white matter while the temporal cortical damage on the left side was much smaller. There was an additional left temporo-parietal lesion. The patient was of average intelligence. His attention, short term memory and learning ability were average or somewhat below average. His old memories were severely affected for the personal-episodic domain and less so for semantic remote memory abilities. Therefore an anatomical dissociation between anterograde and retrograde amnesia is possible at the anterior temporal regions, possibly interacting with the prefrontal cortex; these regions seem necessary for the retrieval of old episodic memories.