Cognitive Blackouts in Mild Cognitive Impairment and Alzheimer's Dementia

BACKGROUND: Cognitive blackouts, e.g. moments of amnesia, disorientation, or perplexity may be an early sign of incipient Alzheimer's dementia (AD). A short questionnaire, the checklist for cognitive blackouts (CCB), was evaluated cross-sectionally in users of a memory clinic. METHODS: The CCB was performed in 130 subjects, who further underwent a neuropsychological and clinical examination. Subjective memory impairment and depressive symptoms were assessed. Differences in the CCB score between diagnostic groups and relationships with cognitive performance, depression, and subjective memory impairment were analyzed. RESULTS: The CCB score was increased in mild cognitive impairment of the amnestic type or mild AD and correctly predicted 69.2% of the respective subjects. It was negatively correlated with cognitive performance, positively correlated with depressive symptoms, and substantially increased in subjects who estimated their memory poorer than that of other persons of their age. DISCUSSION: The CCB may be a helpful screening tool for the early recognition of AD.