Validity of Enhanced Cued Recall Test in the Diagnosis of Alzheimer Dementia and Behavioral Variant of Frontotemporal Dementia

Introduction: Enhanced Cued Recall (ECR) memory test is especially valuable in screening for cognitive impairment in the elderly. ECR uses categorical cues during controlled encoding and recall; tests based on this paradigm are considered to be able to identify hippocampal memory impairment characterized by poor free recall with minimal effect of cueing, typical of Alzheimer's disease (AD). The test could aid in differentiating memory impairment in behavioural variant frontotemporal dementia (bvFTD) versus AD - despite the poor free recall bvFTD patients benefit considerably from cueing. Objective: To establish the validity of ECR in diagnosing memory impairment in AD and bvFTD. Methods: Thirty six patients with probable mild AD (MMSE 21.7 +/- 2.4), 15 with probable bvFTD (MMSE 23.8 +/- 2.4) and 45 healthy elderly (HE) (MMSE 28.96 +/- 1.17) underwent clinical and neuropsychological examination including ECR. Results: There was a statistically significant difference between all groups in all three ECR memory performance scores: free recall, total recall and cueing effect (p < 0.001). Free recall was the most effective score for discriminating dementias from healthy elderly (sensitivity 94% and specificity 100% for AD and sensitivity 80% and specificity 91% for bvFTD); total recall was most effective for differential diagnosis of both dementias (sensitivity 86% and specificity 87%). Conclusion: ECR is a highly sensitive and specific test for identification of memory impairment in AD and bvFTD, and can contribute to the differential diagnosis. We recommend it as highly useful test for clinical practice.