REANALYSIS OF LEARNING-DISORDERS IN RUPTURED ANEURYSM OF THE ANTERIORCOMMUNICATING ARTERY

The aim of this study was to reevaluate short term and long term memor y disorders after anterior communicating artery rupture, then to more specifically assess the importance and the role of forgetting proactiv e and retroactive interferences, impaired memory for temporal order, a ttention disorders and dysexecutive syndrome, and finally MRI-defined brain lesions. Twenty one patients presenting with selective anterior brain injury were assessed at the secondary and late post stroke phase s. The short term memory analysis showed the digit span was reduced at the secondary stage but that mean performances were preserved in the Peterson and Sternberg paradigms. Verbal and visuospatial learning in long term memory showed a severe deficit in free recall, chiefly seria l, and associative recall. Recognition was mildly impaired at the seco ndary phase, and later normalized. A definite and lasting increase of proactive and retroactive interferences and an impairment in discrimin ating the temporal order of word presentations were observed Amnesic i mpairment was relatively well correlated with forgetting severity of i nterferences and temporal order amnesia, so as with disorders of atten tion and executive functions (Wisconsin Card Sorting Test). However, i ntrusions in free recall and false recognitions were not clearly relat ed with the dysexecutive syndrome. The severity of amnesia was associa ted with lesions of the left anterior cingulate cortex, and of the cor pus callosum. These results suggest that these patients mainly had a d eficit in information retrieval, mostly compromising long term memory, but also to a lesser degree short term memory. Forgetting interferenc es and the dysexecutive syndrome probably play an important role in th e decline of mnemonic performance, but do not clearly explain intrusio ns in recall and errors in recognition.