| Abstrakt: |
TO THE EDITOR.— Ziegler et al, in their article entitled "Abrupt Memory Loss Associated With Thalamic Tumor" (Arch Neurol 34:545, 1977), stated that bilateral damage to the hippocampalfornix-mammillary circuits is "undoubtedly" the reason that patients with cerebral neoplasia who show the most striking memory disorder have usually been those with lesions near the midline in the region of the third ventricle where these circuits are in close approximation. In our review of this subject,1 it was not apparent that the hippocampal-fornix-mammillary circuit or any other structure was proved to be consistently enough involved in cases of tumors in the region of the third ventricle to be considered the underlying anatomic substrate to account for the memory impairment observed in such patients. Rather, we concluded that anatomical studies in this regard need further clarification and that the issue remains unsettled.Considerable disagreement exists among investigators concerning the importance of the mammillary |
