Brain Changes Differ by Race With Alzheimer's Disease: Study | WPN World People News

Alzheimer's disease seems to develop differently in the brains of black patients than in whites. And, black people seem more likely to suffer different types of brain changes that also contribute to dementia, a new study reports.

Alzheimer's disease dementia is generally associated with a build-up of substances known as plaques and tangles inside the brain. But, there are other brain changes that can also contribute to dementia, the study authors noted.

For example, the brains of people with dementia sometimes contain infarcts -- tiny areas of dead tissue caused by micro-strokes, the researchers explained. They also might contain Lewy bodies -- another form of abnormal protein build-up in the brain that's usually associated with Parkinson's disease.

Autopsies of black and white Alzheimer's patients revealed that blacks were more likely than whites to experience a mix of dementia-related changes, as opposed to the damage usually associated with "pure" Alzheimer's dementia, according to the study.

"We were surprised that the African Americans were much more likely to have a mixed picture," said expert. "The underlying brain changes were different, which indicates that they probably had different risk factors."

Dementia isn't a specific disease, according to the Alzheimer's Association. Instead, dementia refers to a wide range of symptoms, such as memory loss and communication problems, that are significant enough to interfere with daily life, the association explains.

The study found that among 81 white patients who died, 42 percent only displayed signs of typical Alzheimer's disease. About 51 percent of them had a mix of brain changes that included infarcts and Lewy bodies, the researchers said.

But among 41 black patients who died, about 20 percent displayed only the usual Alzheimer's plaques and tangles. Almost all the rest -- more than 70 percent -- experienced infarcts and Lewy bodies on top of the usual Alzheimer's brain changes.

Blacks also had more frequent and severe blood vessel disease in their brains, such as hardening of the arteries, the investigators found.

These results could help begin to explain why blacks in the United States are twice as likely to develop Alzheimer's than people of European descent, said expert.

Black people are more likely than whites to suffer from heart disease, high blood pressure and type 2 diabetes, all of which increase a person's risk of infarct-causing strokes, expert said.

There also might be specific genetic differences that lead to increased risk of Lewy bodies and other dementia-related brain changes, expert suggested.

Researchers were careful to match the patients, making sure that all suffered from similar levels of Alzheimer's disability prior to death, expert said. After death, autopsies revealed that nearly all of the participants had experienced some brain changes related to either Alzheimer's or dementia.

Learning the differences between black and white Alzheimer's patients will be critically important to researchers who hope to find treatments and cures for dementia, said expert.

The autopsies in this study focused on patients with severe late-stage dementia, noted expert.

Follow-up research hopefully will determine how early in life these brain changes begin, and whether there are ways to reduce people's risk of Alzheimer's and dementia, expert said.

Source: HealthDay News