Dementia: Scientists Find Specific Brain Regions Damaged By High Blood Pressure

More than 55 million people globallyTrusted Source have dementia — an umbrella term for a number of diseases causing memory loss and cognitive decline.

While scientists are still not sure what causes dementia, they know certain conditions may impact whether a person develops dementia or not. One of these is high blood pressure.

Previous research shows people with high blood pressure have a greater risk of developing dementia, including Alzheimer’s disease.

Now, researchers from the University of Edinburgh in the U.K. and Jagiellonian University Medical College in Krakow, Poland, have discovered the specific areas of the brain that may be damaged by high blood pressure and are linked to the development of dementia.

The study was recently published in the European Heart Journal.

High blood pressure — clinically known as hypertension — occurs when the force blood needs to move through the arteries becomes too high.

This can happen if the arteries become damaged or narrower due to cholesterol-containing plaque inside the walls of the arteries.

According to Prof. Tomasz Guzik, professor of cardiovascular medicine at the University of Edinburgh in the U.K. and Jagiellonian University Medical College in Krakow, Poland, and the lead author of this study, having high blood pressure can harm the structure and function of the brain in different ways.

“For instance, hypertension can severely impact the blood vessels in your brain, leading to their reshaping, hardening, and the development of clogged arteries. When blood pressure is elevated, the increased pressure is transmitted from larger blood vessels to smaller ones in the brain, leading to their dysfunction and a condition known as small vessel disease”. 

Additionally, Prof. Guzik said, high blood pressure can also damage the white matter in the brain.

“The white matter is composed of nerve fibers that transmit information between different brain regions, and damage to this area can lead to impaired cognitive function and increase the risk of stroke,” he explained.

For this study, Prof. Guzik and his team used a combination of magnetic resonance imaging (MRI) of brains, genetic analyses, and observational data from thousands of participants of the UK Biobank, COGENT, and the International Consortium for Blood Pressure.

Upon analysis, researchers identified changes in nine areas of the brain related to high blood pressure and worsened cognitive function.

These areas include the putamen, responsible for learning and motor control. Previous research links dysfunction of the putamen to Alzheimer’s disease.

Other areas impacted by high blood pressure included the white matter areas, the anterior thalamic radiation, anterior corona radiata, and the anterior limb of the internal capsule.

Author said the next step in this research will be to design clinical trials and studies focused on imaging the brain areas his research team identified to see if their assessment can help in identifying patients at high risk of cognitive impairment.

“This can provide clinicians with novel tools for future-oriented precision medicine diagnostic and therapeutic approaches. Looking closer at these brain areas can also tell us much more about how the brain functions in the condition of hypertension and identify new ways of improving this function,” he said.

Sources:

Sierra C. Hypertension and the Risk of Dementia. Front Cardiovasc Med. 2020 Jan 31;7:5. doi: 10.3389/fcvm.2020.00005. PMID: 32083095; PMCID: PMC7005583. 

Mateusz Siedlinski, Lorenzo Carnevale, Xiaoguang Xu, Daniela Carnevale, Evangelos Evangelou, Mark J Caulfield, Pasquale Maffia, Joanna Wardlaw, Nilesh J Samani, Maciej Tomaszewski, Giuseppe Lembo, Michael V Holmes, Tomasz J Guzik, Genetic analyses identify brain structures related to cognitive impairment associated with elevated blood pressure, European Heart Journal, 2023;, ehad101, https://doi.org/10.1093/eurheartj/ehad101

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