Dementia Linked to Changes in Brain From High Blood Pressure in Landmark Study

High blood pressure was already known to play an unspecified role in developing dementia. Now, researchers say they have identified specific regions of the brain that are damaged by high blood pressure, possibly contributing to cognitive decline and the development of dementia.

The researchers found that changes to nine parts of the brain were related to higher blood pressure and worse cognitive function. It included the putamen, which is a round structure in the base of the front of the brain that is responsible for regulating movement and governing a range of learning skills.

Raphael Wald, Psy.D., a neuropsychologist with Marcus Neuroscience Institute at Boca Raton Regional Hospital.

 

The new research, published in the European Heart Journal, was co-funded by the European Research Council, the British Heart Foundation and the Italian Ministry of Health. An international team of researchers used MRI imaging data of the brain and genetic information from more than 30,000 participants in the UK Biobank medical database and two other international groups. 

“High blood pressure often means that arteries are getting ‘clogged up’ -- and the arteries in the brain are very small,” explains Raphael Wald, Psy.D., a neuropsychologist with Marcus Neuroscience Institute at Boca Raton Regional Hospital. “If blood vessels are getting clogged, the smallest ones are at a very high risk of a full blockage which causes strokes. This is a huge risk factor for both vascular dementia and Alzheimer’s disease.”

Vascular dementia refers to declining memory and diminished abilities regarding thinking and behavior that result from conditions affecting the blood vessels in the brain. Cognition and brain function can be significantly affected by the size, location, and number of vascular changes.

Symptoms of vascular dementia can begin gradually, or they can occur suddenly, and then progress over time, with some possible brief periods of improvement. Vascular dementia can occur alone or be a part of a different diagnosis. such as Alzheimer's disease or other forms of dementia. When someone is diagnosed with vascular dementia, their symptoms can be similar to the symptoms of Alzheimer's.

The changes to these areas of the brain that researchers pinpointed “included decreases in brain volume and the amount of surface area on the brain cortex, changes to connections between different parts of the brain, and changes in measures of brain activity,” states a news release on the study.

How might these new research findings be used in the future by doctors for both prevention and treatment of dementia?

“This can become another tool that doctors have to assess a person’s risk for stroke,” Dr. Wald. “We can also use this information as a means of detecting specific types of strokes depending on how patients present. It will also allow us to look further into ways to protect these areas of the brain when they are at risk.”

Nearly half of U.S. adults have high blood pressure, according to the American Heart Association. Only about 1 in 5 have their condition under control, which can be done with regular exercise and a healthy diet, and possibly medication. Researchers behind the new study conceded that more research is needed on the effects of blood pressure on cognitive function “to determine precise causal pathways and relevant brain regions.”

Dr. Wald agrees: “What would be helpful for clinicians is a formal set of guidelines and protocols for identifying individuals at risk for stroke with the benefit of this research.”