AHA/ASA Issue Scientific Statement on Vascular Dementia

  From Medscape Education Clinical Briefs

News Author: Megan Brooks
CME Author: Désirée Lie, MD, MSEd

 07/28/2011Stroke. Published online July 21, 2011.

Study Highlights

• The overall prevalence of dementia in developed countries is 5% to 10% in persons 65 years and older. The prevalence of Alzheimer's disease doubles every 4.3 years, with vascular dementia doubling every 5.3 years.
• VCI embraces the spectrum of severity from prodrome to full-blown manifestations of cognitive impairment including stroke, and from pure Alzheimer's disease to vascular dementia.
• Criteria for a diagnosis of VCI should be based on the presence of 2 factors: demonstrated cognitive disorder (such as dementia) by neuropsychological testing, and a history of stroke or evidence of vascular disease by neuroimaging testing.
• It is often difficult to determine if the cognitive impairment is the result of vascular factors or deterioration in Alzheimer's disease.
• Magnetic resonance imaging and other neuroimaging techniques are useful for detection of VCI and provide evidence that subcortical forms with white matter hyperintensities and small deep infarcts are common.
• Risk factors for vascular dementia and VCI can be nonmodifiable and modifiable.
• Nonmodifiable factors include increasing age. There is a suggestion that ethnicity may be a risk factor, with a higher incidence in blacks and Hispanics vs whites.
• Genetic factors are involved in Alzheimer's disease, but their role in VCI is unclear at present.
• Modifiable risk factors include education, diet, physical activity, body mass index, and social support.
• Although lower education has been cited as a risk for VCI, there may be confounders explaining the link.
• Antioxidants have been suggested as being protective for VCI, but prospective randomized trials do not support a benefit.
• High intake of fish has been found to be inversely related to the risk for VCI.
• The role of vitamin D, folic acid, and the B vitamins remains unclear. However, antioxidants and B vitamins are not considered useful in the prevention of VCI, even when homocysteine levels are improved.
• Long-term physical activity has been shown to be protective for VCI and for preservation of brain health.
• Obesity and smoking have both been implicated in the risk for VCI.
• The current recommendations to reduce the risk for VCI are smoking cessation, moderate alcohol intake, weight control, and moderate physical activity.
• The Mediterranean diet has been found to be helpful in the prevention of cognitive decline.
• In persons at risk for VCI, other recommendations to reduce risk include treatment of atrial fibrillation, hypertension, hyperglycemia, and hypercholesterolemia, but it is unclear if treatment of inflammation would affect risk.
• The longer the treatment of hypertension, the greater the benefit in the prevention of VCI. Compared with the oldest old, the youngest old experience the greatest benefits.
• In general, prevention of chronic vascular disease may help to reduce the burden of VCI, dementia, and recurrent stroke.
• For treatment, donepezil can be useful for cognitive enhancement in patients with vascular dementia.
• Galantamine may be beneficial for mixed Alzheimer's disease and vascular dementia.
• Rivastigmine and memantine are not considered useful in vascular dementia at present.
• Antiaggregant therapy has not been found to be effective.
• Cognitive rehabilitation and cognitive stimulation have not been proven to be useful so far; more studies are needed.
• Acupuncture was found to be useful in 1 rodent study, but a Cochrane review found inconclusive results in human studies.
• Recent recommendations for stroke prevention from the AHA are a useful guide for VCI prevention in risk management.
• The authors concluded that early detection of VCI with use of neuropsychological batteries, neuroimaging, and preventive strategies — especially prevention of cardiovascular disease — were important approaches to improve outcomes.

Clinical Implications

• Risk factors for VCI are similar to those for cardiovascular disease, and risk reduction involves similar approaches.
• Donepezil and galantamine may be beneficial for VCI, but rivastigmine and memantine, cognitive stimulation, and cognitive rehabilitation have not been found to be helpful.