Mild Cognitive Impairment

Purpose of Review: As individuals age, the quality of cognitive function becomes an increasingly important topic. The concept of mild cognitive impairment (MCI) has evolved over the past 2 decades to represent a state of cognitive function between that seen in normal aging and dementia. As such, it is important for health care providers to be aware of the condition and place it in the appropriate clinical context.

Recent Findings: Numerous international population-based studies have been conducted to document the frequency of MCI, estimating its prevalence to be between 15% and 20% in persons 60 years and older, making it a common condition encountered by clinicians. The annual rate in which MCI progresses to dementia varies between 8% and 15% per year, implying that it is an important condition to identify and treat. In those MCI cases destined to develop Alzheimer disease, biomarkers are emerging to help identify etiology and predict progression. However, not all MCI is due to Alzheimer disease, and identifying subtypes is important for possible treatment and counseling. If treatable causes are identified, the person with MCI might improve.

Summary: MCI is an important clinical entity to identify, and while uncertainties persist, clinicians need to be aware of its diagnostic features to enable them to counsel patients. MCI remains an active area of research as numerous randomized controlled trials are being conducted to develop effective treatments.

Address correspondence to Dr Ronald C. Petersen, Mayo Clinic, Department of Neurology, 200 1st St SW, Rochester, MN 55905-0001, [email protected].

Relationship Disclosure: Dr Petersen serves on the board of directors for the Alzheimer’s Association and receives personal compensation for serving as chair of the data monitoring committees for Janssen Alzheimer Immunotherapy and Pfizer Inc. Dr Petersen receives personal compensation as a consultant for Biogen, Eli Lilly and Company, the Federal Trade Commission, Genentech, Inc, Hoffmann la Roche, Inc, and Merck & Company, Inc. Dr Petersen receives grant and funding support from the Mayo Foundation for Education and Research, the National Institute on Aging, and the Patient Centered Outcomes Research Institute (PAT 206548). Dr Petersen receives royalties from Oxford University Press.

Unlabeled Use of Products/Investigational Use Disclosure: Dr Petersen discusses the unlabeled/investigational clinical trial results for mild cognitive impairment.