What’s the difference between vascular dementia and Alzheimer’s?

Q. What’s the difference between vascular dementia and Alzheimer’s disease?

A. Alzheimer’s disease is by far the most common cause of dementia (a significant loss of memory and cognitive functions), but vascular dementia is one of several other forms of dementia. In Alzheimer’s disease, nerve cells throughout the brain die off, and abnormal proteins accumulate in the brain for reasons not entirely known. Vascular dementia, in contrast, is the result of impaired blood flow to the brain, usually by a series of small, imperceptible strokes. Avi Almozlino, chief of neurology at Newton-Wellesley Hospital, says that people may not be aware of having strokes, “but over time there is accumulating damage to the brain.”

He says that Alzheimer’s disease largely affects the gray matter (the main bodies of nerve cells), while vascular dementia affects the white matter (the connecting fibers in the brain). Though both involve memory and cognitive impairments, vascular dementia may also affect movement and walking, and may progress in a stepwise fashion rather than gradually.

We don’t know how to prevent Alzheimer’s dementia, but vascular dementia involves the same risk factors known to increase your risk of heart disease or stroke, including high blood pressure, high cholesterol, diabetes, smoking, and lack of physical activity. Addressing these risk factors could potentially help to prevent or slow the condition.

Several treatments can relieve symptoms of Alzheimer’s disease, but they don’t slow its course. Those same drugs are sometimes used to treat vascular dementia, Almozlino says, but physicians focus on controlling underlying risk factors.