[Amnestic syndromes and confabulation in infarction of the posterior cerebral artery area].

The Posterior Cerebral Artery (PCA) supplies the greatest part of the limbic system. Several authors have reported amnestic syndromes in PCA infarcts. Amongst 76 patients with a CT proven PCA infarct, 21 suffered anterograde amnesia. Confabulations were associated in 5 cases. We studied CT scans according to previously reported templates in the 21 amnestic patients: all patients with confabulations had a paramedian or a tuberothalamic infarct associated with a cortical infarct within the superficial territory of the PCA. None of the 16 remainders had a thalamic lesion. These results emphasize the role of the thalamus especially of the dorsomedial nucleus in the pathogenesis of confabulation. The underlying mechanism could imply fronto-cingular deafferentation.