Detection of Abnormal Memory Decline in Mild Cases of Alzheimer's Disease Using CERAD Neuropsychological Measures

TLDR

The study aimed to identify which CERAD memory tasks most effectively distinguish early Alzheimer’s disease patients from cognitively normal elderly controls and differentiate dementia severity levels. Researchers stratified CERAD Alzheimer’s patients by mild, moderate, or severe dementia, matched them with controls, and applied multivariate analyses and cut‑score thresholds to evaluate each memory measure’s discriminative power. Delayed recall emerged as the strongest discriminator, while immediate recall, intrusion errors, and recognition memory performed poorly and none of the measures reliably staged dementia severity; thus delayed recall should be incorporated into community screening batteries.

Abstract

The present study was designed to determine which of the memory tasks included in the CERAD (Consortium to Establish a Registry for Alzheimer's Disease) neuropsychological battery best differentiate patients with early Alzheimer's disease from cognitively normal elderly control subjects and also best distinguish between the various levels of severity of the dementia process. A sample of CERAD patients with Alzheimer's disease was stratified by disease severity into those with mild, moderate, or severe dementia and matched with control subjects for sex, age, and education. Using multivariate procedures and cutting scores, the efficacy of each memory measure in distinguishing between these groups and control subjects was determined. The test for delayed recall was found to be the best overall discriminatory measure. The other tests of memory, ie, immediate recall, intrusion errors, and recognition memory, had poor overall discriminability. None of the CERAD memory measures were found to be particularly powerful in staging the severity of dementia. These findings suggest that tests for delayed recall may be particularly useful in the early detection of Alzheimer's disease and should be considered in screening batteries for dementia in community surveys.