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Strategies to Lower the Risk of Stroke-Related Dementia

Strategies to Lower the Risk of Stroke-Related Dementia

What is the risk of dementia in patients who have had an ischemic stroke? And which therapies are most effective in reducing this risk? ---- MD Population-based epidemiologic studies show that the risk of dementia is 4 to 6 times higher in patients who have had a stroke than in those who have not.1 In hospitalized cohorts, dementia develops in a quarter to a third of patients 3 months after a stroke,2 and up to 60% have impairment in at least 1 cognitive domain. Compared with persons who have not had a stroke, patients with cerebrovascular disease have a 2- to 10-fold higher risk of incident dementia, particularly when multiple infarcts are present.3 In the general population, silent or unrecognized brain infarcts also raise the risk of dementia in the subsequent 3 years,4 perhaps because they are a marker of high risk of additional infarcts.5 Cognitive decline in patients with cerebrovascular disease can result from the stroke itself when a large volume of brain is affected by ischemia or hemorrhage or when the lesion, because of its location in a strategic area, interrupts brain circuits that are critical for cognition. Alternatively, vascular and neurodegenerative changes, which are common in the brains of elderly persons,6 can coexist and lead to a "mixed dementia." These pathologic processes act synergistically to impair cognition.7 Clearly, strategies that reduce the incidence of stroke will reduce the burden of cognitive impairment and dementia. Primary prevention strategies for stroke include lifestyle changes (a healthful diet, regular exercise, smoking cessation) and aggressive management of risk factors, including hypertension, nonvalvular atrial fibrillation, and hypercholesterolemia. 8 Proven secondary prevention strategies include the use of antihypertensive agents, particularly angiotensin-converting enzyme inhibitors and thiazide diuretics, 9,10 and antiplatelet agents, as well as management of atrial fibrillation and symptomatic high-grade carotid artery stenosis. Data from available studies suggest that statin therapy may reduce the risk of stroke by 25%.11 Trials to test the effectiveness of statins in secondary stroke prevention are currently under way, as are trials of vitamin therapy to reduce homocysteine levels. ---- Jos G. Merino, MD
Assistant Professor of Neurology
University of Florida College of Medicine


Zhu L, Fratiglioni L, Guo Z, et al. Association of stroke with dementia, cognitive impairment, and functional disability in the very old: a population-based study. Stroke. 1998;29:2094-2099.
2. Tatemichi TK, Desmond DW, Mayeux R, et al. Dementia after stroke: baseline frequency, risks and clinical features in a hospitalized cohort. Neurology. 1992;42:1185-1193.
3. Schneider JA, Wilson RS, Cochran EJ, et al. Relation of cerebral infarctions to dementia and cognitive function in older persons. Neurology. 2003;60:1082-1088.
4. Vermeer SE, Prins ND, den Heijer T, et al. Silent brain infarcts and the risk of dementia and cognitive decline. N Engl J Med. 2003;348:1215-1222.
5. Breteler MM. Vascular risk factors for Alzheimer’s disease: an epidemiologic perspective. Neurobiol Aging. 2000;21:153-160. 6. Neuropathology Group. Medical Research Council Cognitive Function and Ageing Study (MRC CFAS). Pathological correlates of late-onset dementia in a multicentre, community-based population in England and Wales. Lancet. 2001; 357:169-175.
7. Snowdon DA, Greiner LH, Mortimer JA, et al. Brain infarction and the clinical expression of Alzheimer disease. The Nun Study. JAMA. 1997;277:813-817.
8. Straus SE, Majumdar SR, McAlister FA. New evidence for stroke prevention: scientific review. JAMA. 2002;288:1388-1395.
9. Yusuf S, Sleight P, Pogue J, et al. Effects of an angiotensin-converting-enzyme inhibitor, ramipril, on cardiovascular events in high-risk patients. The Heart Outcomes Prevention Evaluation Study Investigators. N Engl J Med. 2000;342:145-153.
10. Randomised trial of a perindopril-based blood-pressure-lowering regimen among 6,105 individuals with previous stroke or transient ischaemic attack. Lancet. 2001;358:1033-1041.
11. Collins R, Armitage J, Parish S, et al. Effects of cholesterol-lowering simvastatin on stroke and other major vascular events in 20536 people with cerebrovascular disease or other high-risk conditions. Lancet. 2004;363:757-767.

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