There has been great progress in the diagnosis and treatment of Alzheimer disease (AD) and related dementias thanks to the availability of well-validated diagnostic criteria (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV); National Institute of Neurological and Communicative Disorders and Stroke–the Alzheimer’s Disease and Related Disorders Association [NINCDS-ADRDA]); and a large number of randomized clinical trials using cholinesterase inhibitors (AChEIs) and Memantine. Work from specialized neurological clinics suggests that mild cognitive impairment (MCI) is an early stage of AD, and there is a temptation for neurologists to prescribe AChEIs in this population. On the other hand, there is epidemiological evidence that many subjects labeled as having MCI do not worsen over time and may revert to normal cognitive abilities. A diagnosis of MCI as a predementia stage of AD in such individuals would be inaccurate and carry a heavy personal and societal burden. Reversible causes of MCI may be found, such as depression, upper airway obstruction, and a variety of metabolic, nutritional, or sensory impairments. Since MCI does not constitute a homogeneous clinical syndrome, it is inappropriate to propose a specific drug treatment such as AChEIs, but the recognition that MCI is a risk state toward further cognitive decline is clinically relevant, and control of risk factors such as systolic hypertension, hypercholesterolemia, diabetes mellitus, atrial fibrillation, transient ishemic attacks, and strokes may delay progression to dementia.
Gauthier S, Touchon J. Mild Cognitive Impairment Is Not a Clinical Entity and Should Not Be Treated. Arch Neurol. 2005;62(7):1164-1166. doi:10.1001/archneur.62.7.1164