Evaluating different aspects of prospective memory in amnestic and nonamnestic mild cognitive impairment.

Prospective memory, the inability to remember an intended action, is a common complaint, but not formally assessed in most clinical and research studies of mild cognitive impairment (MCI). In this study, patients with amnestic mild cognitive impairment (aMCI), non-amnestic cognitive impairment (naMCI), and cognitively normal (CN) elders were assessed using the Miami Prospective Memory Test (MPMT). A unique aspect of the paradigm was that participants were scored for intention to perform, accuracy in recollection for specific elements of the task, and the need for reminder cues. Excellent test-retest stability was obtained for MPMT Event-Related (ER), combined Time-Related (TR) subscales, and total MPMT score for aMCI subjects. MPMT impairments were observed in 48.6% of aMCI, 29.4% of naMCI, and 10.0% of normal elderly participants. Prospective memory deficits were common in participants with aMCI, and occurred in almost a third of naMCI participants. Intention to perform and need for reminder cues were significantly more impaired than retrospective memory for specific details of the task. It is concluded that assessment of different elements of prospective memory is important in MCI research and that inability to remember intended actions is a significant feature in those as risk for Alzheimer's disease.