Dementia is a serious public health problem with an increasing prevalence because of the aging of the population.¹ Dementia is characterized by global cognitive decline sufficient to affect functioning.² It is a chronic illness with seriously disabling effects for patients, their families, and society.² Mild cognitive impairment (MCI) describes cognitive impairment in elderly persons not of sufficient severity to qualify for a diagnosis of dementia.³ Individuals with MCI have complaints of impairment in memory or other areas of cognitive functioning usually noticeable to those around them. In addition, their performance on memory and cognitive tests is below that expected for their age and education. However, their day-to-day functioning is generally preserved. Several operational definitions for MCI have been proposed.^3,4 Mild cognitive impairment is a chronic condition and may be a precursor to Alzheimer-type dementia.⁴ Mild cognitive impairment is often worrisome to patients and families, and is increasingly a presenting complaint for care.

Physical activity may help preserve cognitive function and decrease dementia risk, but epidemiologic findings are inconsistent. The authors conducted a prospective study to determine the association between physical activity and risk of dementia, Alzheimer's disease, and vascular dementia. The US study population comprised 3,375 men and women aged 65 years or older, free of dementia at baseline, who participated in the Cardiovascular Health Cognition Study in 1992–2000. Leisure-time energy expenditure and an activity index reflecting number of different physical activities were calculated. Analyses were based on Cox proportional hazards models. There were 480 incident cases of dementia over an average of 5.4 years of follow-up. After multivariate adjustment, participants in the highest quartile of physical energy expenditure had a relative risk of dementia of 0.85 (95% confidence interval: 0.61, 1.19) compared with those in the lowest quartile, and participants engaging in ≥4 activities had a relative risk of dementia of 0.51 (95% confidence interval: 0.33, 0.79) compared with those engaging in 0–1 activity. These associations were more marked in apolipoprotein E genotype (APOE) ε4 allele noncarriers but were absent in carriers. A similar pattern was observed for Alzheimer's disease and vascular dementia. Mechanisms to explain the observed relations deserve further study.

Co-equal last authors. Background: Deep brain stimulation (DBS) is used to modulate the activity of dysfunctional brain circuits. The safety and efficacy of DBS in dementia is unknown. Objective: To assess DBS of memory circuits as a treatment for pa

ALZHEIMER DISEASE (AD) is a progressive disease with debilitating consequences for patients, their families, and the public welfare. While cognitive and functional decline is the hallmark of AD, neuropsychiatric disturbances afflict about 90% of the patients.^1-8 The treatment of neuropsychiatric disturbances is an essential part of the treatment of AD.^2,9,10 Despite this, the evidence supporting the use of interventions for these disturbances has been sparse.¹⁰