What Is Vascular Dementia?

Although vascular dementia doesn't carry the same name recognition as Alzheimer's disease, maybe it should, because both are so devastating. Possibly the most important difference between these two brain conditions is that vascular dementia is more preventable. Here's why you should put vascular dementia on your radar and take action now:

Vascular dementia involves blood circulation to your brain. The umbrella term dementia encompasses many types, including Alzheimer's disease, Lewy body, frontotemporal and vascular dementia. "This particular form is caused by blockages of the blood vessels that feed the brain," says Dr. Caroline Harada, a geriatrician with the University of Alabama at Birmingham. A blockage could be big enough to cause a stroke or multiple strokes, she explains, and dementia could immediately occur. Small-vessel disease, by contrast, involves tiny capillaries that feed the brain cells. In the absence of stroke, she says, "there never is one big, dramatic moment. It's more of a gradual, slow damage to the brain that will eventually cause dementia."

Vascular dementia is common, too. In 2018, an estimated 5.7 million Americans were living with Alzheimer's dementia, according to an Alzheimer's Association report. If you compared different types of dementia, pure Alzheimer's disease would take up about 60% percent of a pie chart, Harada says. Pure vascular dementia would represent about 15% percent. Another 15% to 20% would be people who have a combination of Alzheimer's and vascular dementia. In 2017, more than 16,000 people died of vascular dementia in the U.S., according to the Centers for Disease Control and Prevention.

[See: 9 Strategies to Reduce Falls for People With Dementia.]

Vascular dementia's course is often unpredictable. Vascular dementia can slowly creep up on people, not becoming obvious for many years. Once diagnosed, the condition can feel like a roller-coaster ride. "Vascular dementia seems to fluctuate a bit more than nonvascular dementia," says Dr. Bruce Miller, director of the Memory and Aging Center at University of California--San Francisco. "There are, in many cases, halting improvements for a short period of time, then a second stroke happens and worsening again. It's a much more rocky and up-and-down kind of course."

Vascular dementia chips away at executive function. Alzheimer's and vascular dementia appear to affect different types of brain function. Alzheimer's tends to erode a person's memory and word-finding ability. By contrast, vascular dementia is more likely to affect executive function. "Typically, what tends to happen first is difficulty with attention span and difficulty with the speed at which you process information," Harada says. "And difficulty with executive function -- judgment, reasoning, complex problem-solving -- all those tasks. Those are a lot more subtle and it can take families longer to clue in that there's really a problem."

[See: 10 Seemingly Innocent Symptoms You Shouldn't Ignore.]

Vascular dementia shares risk factors with heart disease and stroke. Medical conditions and health behaviors that put people at risk for stroke and heart disease also make them more vulnerable to vascular dementia. Smoking, hypertension, diabetes, lack of exercise and high cholesterol are all cardiovascular risk factors. It's known that people with atrial fibrillation, or AFib, are more likely to develop vascular dementia than the general population. The connection: Having AFib puts you at much higher risk for stroke, thus raising your risk for dementia, Harada explains.

Diabetes poses a significant increased risk. People with Type 2 diabetes are at markedly higher risk for developing dementia, according to a large study published in the February 2016 issue of Diabetes Care. The evaluation of more than 100,000 dementia cases shows that people with diabetes face a roughly 60 percent higher dementia risk compared to those without diabetes. Researchers also found that women with diabetes have a 19% higher risk of developing vascular dementia, specifically, than men.

The genetic impact is unclear. The genetic component for vascular dementia is not as clear-cut as for Alzheimer's disease. No one has yet been able to find a gene that controls run-of-the mill vascular dementia, Harada says. However, she adds, with a rare type of vascular dementia called CADASIL, which causes multiple strokes, the genetic mutation causing the condition has been identified.

Controlling chronic health conditions reduces vascular dementia risk. Evidence supports tight control of diabetes for reducing dementia risk. For people with high blood pressure, most findings over the last decade support the importance of keeping your systolic blood pressure (the top number) under control, Miller says. However, he adds, too-tight blood pressure should be avoided, "because when people's vessels start to become occluded, if their blood pressure drops, it can really cause worsening of the vascular dementia."

Aging is an unavoidable dementia risk factor. Many cardiovascular risk factors like diabetes do have a genetic element, Miller notes. "So the risks for vascular dementia have a genetic component," he says. "But now, in modern medicine, so many of them can be prevented." That holds true until you reach your 80s or 90s, he adds. "Then, there is a higher likelihood -- even if we don't have any genetic or known risk factors -- that the shutting down of the blood vessels of the brain happens."

Wellness exams can screen for early dementia in older adults. Medicare covers an annual wellness visit for older adults that should include a cognitive assessment. A medical history and brief tests like the Montreal Cognitive Assessment, or MoCA, can reveal signs of cognitive impairment. "These wellness exams are when the risk factors for vascular dementia are picked up," Miller says. "When (health practitioners) do cognitive screening, it's going to show there are subtle cognitive changes." Primary care physicians or geriatricians may order blood tests to rule out other conditions. Patients may undergo brain-imaging studies like MRI. "In some cases, in the course of an evaluation, an MRI will show extensive vascular changes," Miller says. A neurologist can do further testing to pinpoint the type and stage of dementia.

Early detection makes a difference. Vascular dementia is an "epidemic," Miller says. "It's silent, often. If it is recognized, further damage can often be prevented -- depending on the cause. The earlier we intervene in someone's course, the more likely a good outcome will occur. And there are certainly many good outcomes in people. But it has to be early. It can't be after there's a series of strokes that could have been prevented. That is a real human tragedy." Family members should seek expert help from a specialist when the health of a person's heart or brain blood vessels is at stake, he says.

Alzheimer's drugs don't work as well for vascular dementia. Because the disease process, or pathophysiology, is so different for these two types of dementia, treatment is different, too. "We have some drugs that work for Alzheimer's, such as cholinesterase inhibitors, and NMDA antagonists like Memantine," Harada says. "Those drugs do not seem to work as well for patients who have vascular dementia." Cholinesterase inhibitor drugs include Aricept, Razadyne and Exelon.

[See: 14 Ways Alcohol Affects the Aging Process.]

Vascular dementia is tied to shorter life expectancy. On average, an individual with Alzheimer's disease lives four to eight years after being diagnosed, but can live as long as 20 years, according to the Alzheimer's Association. In contrast, people with vascular dementia live about five years after symptoms start, according to the association. Oftentimes, a stroke or heart attack is the cause of death.

Quality of life is a major goal. Once someone is diagnosed with vascular dementia, "focusing that time on maintaining a really good quality of life and making sure that the person is well-cared for and surrounded by people who love them" become the care priority, Harada says. "And trying to be as active as they can, doing things they enjoy."

Lifestyle changes can lower your dementia risk. Exercise and a healthy diet can help you avoid vascular dementia, to some extent. Heart-healthy diets -- such as the DASH and Mediterranean diets -- are geared toward better cardiovascular health in general. The MIND diet, which combines the two, was developed specifically to reduce dementia risk. Not smoking -- or quitting -- is good for your vascular health as well. Physical and mental exercise are both important, Harada emphasizes. "Brain exercise doesn't have to be crossword puzzles and classic brain games," she says. "It can be anything that engages your mind. Just having a conversation with a friend is brain exercise."