Issues in memory assessment of the elderly

Anterograde memory deficits are present following lesions occurring throughout the cerebrum. However, the most pronounced deficits are present following lesions to mesial temporal lobe structures, dorsomedial thalamus, basal forebrain, or their functional interconnections. Although some differences between types of amnesias have been described in the experimental literature (for example, rate of forgetting, release from proactive interference), these differences are primarily of theoretical importance and are not employed when making individual patient inferences. Because the primary memory deficits associated with the various etiologies, including psychiatic disturbance, appear similar psychometrically, the clinician must rely on information independent from the memory assessment in order to infer etiology of deficit. Thus, the cause of the memory deficit is usually determined by independent confirmation of cerebral pathology, such as with CT and MR imaging, and the role of neuropsychological assessment is to quantitatively assess the degree of memory impairment present.