Cognitive support at episodic encoding and retrieval: similar patterns of utilization in community-based samples of Alzheimer's disease and vascular dementia patients.

The hypothesis that Alzheimer's disease (AD) and vascular dementia (VaD) differ in the pattern of episodic memory was examined in this study. Demented patients with AD and VaD and normal old adults were assessed on episodic memory tasks, including free recall and recognition of slowly and rapidly presented unrelated words and free and cued recall of organizable words. Results showed a general deficit in both demented groups across all memory variables, although the AD and VaD patients were indistinguishable across all measures. The normal old showed proficient utilization of more study time, organizability, and category cues. By contrast, the AD and VaD patients were able to benefit from cognitive support only when guidance was provided at both encoding and retrieval. In addition, in the normal old, recall of unrelated words was characterized by a relatively equal contribution from primary and secondary memory, whereas the demented patients relied predominantly on primary memory. The results suggests a similarity between AD and VaD patients with regard to the nature of the episodic memory impairment, despite etiologic differences between the diseases.