Memory disorders in patients with cerebral tumors.

In patients with cerebral tumors, deficits in declarative episodic memory typically result from damage to structures of the Papez circuit. These deficits can arise directly from the action of the tumor mass or indirectly from the surgical intervention. Memory deficits are also frequently seen in patients who show no direct involvement of the Papez circuit. In these patients, the memory impairment probably results from disruption of frontal lobe functioning (caused by localization of the tumor at this level or disconnection from subcortical afferents). Here, I review the neuropsychological tools used to differentiate amnesic syndromes resulting from lack of consolidation of new memory traces (as a consequence of damage to the Papez circuit) from amnesias resulting from reduced efficiency of elaborative encoding and/or strategic retrieval processes (as a consequence of frontal lobe damage). The clinical and rehabilitative implications of this distinction are briefly discussed.