Vascular Dementia

How is vascular dementia diagnosed and differentiated from Alzheimer disease?

Response from David B. Reuben, MD Professor and Archstone Foundation Endowed Chair, Department of Medicine, University of California, Los Angeles; Chief, Division of Geriatrics, UCLA Medical Center, Santa Monica, California

Making a diagnosis of vascular dementia is complicated for several reasons. First, vascular dementia has multiple causes and clinical types. Second, in contrast to Alzheimer disease, the diagnosis of vascular dementia has no pathognomonic criteria. Third, the clinical diagnostic criteria are poorly validated. Fourth, on MRI, white-matter lesions, which are related to cerebral hypoperfusion or ischemia, are nonspecific findings yet often are interpreted as diagnostic. Fifth, many patients with vascular dementia also have other causes of dementia (eg, Alzheimer disease)—so-called "mixed dementia."

Several causes and presentations of vascular dementia have clinical value. Perhaps the most obvious patients are those who meet criteria for dementia and have sustained a clinical stroke—either large artery (usually cortical) or small artery (lacunes) in subcortical areas. Strokes are usually confirmed by neuroimaging (MRI is more sensitive than CT) that demonstrates either multiple infarcts or a single strategically placed infarct (eg, angular gyrus, thalamus, brain forebrain, posterior cerebral artery, or anterior cerebral artery).