Defect of memorizing of hippocampal-mammillary origin: a review

Abstract

The inability to acquire new memories as opposed to the preservation of previously fixed ones has been designated in the literature as "defect memorizing" (amnesie de memoration). Unable to retain new knowledge, the patient lives on memories acquired before his illness and soon develops retrograde amnesia and, consequently, fabricates. This defect of memorizing can coexist with confusion or insanity as well as occur in its pure form. It appears in various illnesses such as chronic alcoholism, toxic or infectious encephalopathy, Wernicke''s presbyophrenia, skull trauma and tumours of the base of the brain. It is also found in cases of bilateral surgical excision of the hippocampus which implies that this syndrome depends on the location of the lesions. It seems that the mammillary bodies and the hippocampus have a predominant role in defects of memorizing whereas cortical and subcortical areas have an important role in recalling old memories.