A new case of retrograde amnesia with abnormal forgetting rate

The classic amnesic syndrome is characterised by a severe anterograde amnesia and a less important retrograde amnesia with sparing of the semantic component. We report the case of a patient who showed a global amnesic syndrome following a mild head injury. Initially, amnesia was both anterograde and retrograde, and also involved semantic knowledge. Two years later the picture had changed remarkably. The retrograde deficit for autobiographical events was still total, while semantic memory had recovered to a large extent. Learning had also greatly improved, but only if assessed after a short delay; abnormally rapid forgetting rate were found at longer intervals. This pattern of impairment does not lend itself to an easy interpretation. However, the hypothesis of a consolidation deficit may be advanced.