Aim: We examined the level of awareness of memory deficits in 63 patients with Alzheimer's disease (AD), 17 patients with dementia with Lewy bodies (DLB), 14 patients with vascular dementia (VaD), and 56 patients with amnestic mild cognitive impairment (MCI).
Methods: The unawareness of memory impairment was evaluated with a standardized memory questionnaire system based on the Everyday Memory Checklist (EMC). The EMC scores for the patient's own rating, the caregivers' rating and the unawareness score, defined as the discrepancy between these (caregiver rating-patient rating), were analyzed.
Results: Although the EMC self-rating scores were comparable among the four groups, the EMC scores in caregivers were significantly higher in the AD group than in the DLB, VaD, and MCI groups. Therefore, the unawareness scores were significantly higher in the AD groups than in other groups. When an unawareness score of 9 or more was defined as significant, impaired awareness was found in 41 (65%) patients with AD, 1 (6%) patient with DLB, 5 (36%) patients with VaD, and in 19 (34%) patients with MCI.
Conclusion: We found that impaired awareness was found in two-thirds of patients with mild AD and even in one-third of patients with MCI. However, other dementias, in particular DLB, had less severe and less frequent unawareness of memory deficits than AD, suggesting the difference in the pathophysiology between them.