[Retrograde memory after rupture of aneurysms of the anterior communicating artery]

The aim of this study was to investigate deficits of retrograde memory, semantic, autobiographical, and for famous events, associated with prefrontal, cingulate and subcortical lesions resulting from anterior communicating artery rupture. Analyses were performed during the secondary phase post-stroke in 16 patients, and performances were compared to those of an equivalent number of matched control subjects. Semantic investigations revealed a significant deficit in each task using evocation, more especially categorical and literal evocations, and the verbal subtests of the WAIS-R: vocabulary, information, comprehension, and similarities. Furthermore, the capacity to categories was preserved. The Crovitz paradigm, which evaluated the autobiographical memory showed a severe deficit in the evocation of events associated with a precise context in place and moreover in time, with a clear tendency to produce semantic responses, but without significant increase in confabulations. The questionnaire on famous events (1936-1985) did not document deficit in recognition and recall. Furthermore, the patients disorder was more severe in learning new information. Memory disorders were best explained by the severity of lesions in the medio-basal frontal and cingulate cortices, but also by the subcortical injury. Significant correlations were observed between the retrograde memory performance and "frontal" tasks, more especially the WCST; however, similar relations were also documented between learning new information and "frontal" performance. These data suggest that retrograde amnesia results from a selective impairment in accessing old memory representations, and that cognitive processes more specifically altered have tight relations with the capacity to organize the search and to shift.