Are hippocampal lesions sufficient to cause lasting amnesia?

Abstract

A 57-yr-old woman developed severe generalized amnesia following an embolic stroke. The amnesia persisted until her death 9 mo. later. The left hemisphere had a large infarction of the medial temporal-occipital region, while the right showed only a small infarct limited to the posterior 2/3 of the hippocampus. If bilateral lesions are necessary for the production of permanent amnesia, the findings support the view that the hippocampus is itself a critical structure in the medial temporal diencephalic memory circuit.