Mild cognitive impairment

Interest in the continuum from normal cognition, to mild cognitive impairment (MCI), to early Alzheimer's disease has increased considerably since the approval of pharmacologic agents for the symptomatic treatment of Alzheimer's disease. This trend is likely to continue over the next several years as the research community hopes to develop agents for the primary and secondary prevention of Alzheimer's disease. Although no consensus regarding specific clinical criteria for MCI exists there is general agreement regarding its conceptualization, namely cognitive impairment in the absence of dementia. Data suggest that MCI is common and associated with significant mortality and morbidity. It also appears to be due, in large part, to the same pathologic processes responsible for other age-related dementias, especially Alzheimer's disease, suggesting that the public health burden of these conditions is probably much greater than currently recognized. There are no current recommendations regarding specific treatment for MCI. However, a number of clinical trials are underway, and data should be forthcoming over the next several years. Future studies are likely to emphasize the identification of risk factors for MCI. Although some data suggest that risk factors for MCI are likely to be similar to those for Alzheimer's disease, this is far from certain, and rigorous, large, longitudinal population-based studies will be required to identify risk factors.