Authors: Alice Weatherston
Research presented recently at the American Heart Association’s 2015 High Blood Pressure Conference (16 – 19 Sept; Washington DC, USA) has revealed, through a novel imaging technique, that some individuals suffering from high blood pressure also exhibit nerve tract damage within the brain.
“We already have clear ways to explore the damage high blood pressure can cause to the kidneys, eyes, and heart. We wanted to find a way to assess brain damage that could predict the development of dementia associated with vascular diseases,” explained Daniela Carnevale (Sapienza University of Rome, Italy), the study’s senior author.
Using a technique termed diffusion tensor imaging (DTI), an enhancement of magnetic resonance imaging, the research team made a comparison between the structural and functional properties of the key connections between different brain regions. Of the 30 study participants, 15 were on prescribed medication for moderate to severe high blood pressure and the remainder had normal blood pressure. All participants also took part in a cognitive assessment as part of the study.
While no study participants indicated brain abnormalities on standard MRIs, DTI revealed a range of adverse impacts on the brains of individuals with high blood pressure. The damage detected was to the area of the brain responsible for certain cognitive skills, decision-making, and the ability to regulate emotions, including nerve fibers, brain fibers and limbic system fibers.
The effect of the brain damage was underlined by the cognitive assessment, which indicated that individuals with high blood pressure performed worse than those with normal blood pressure in two different assessments of cognitive function and memory respectively. Verbal functioning or their ability to perform daily activities was not affected.
“DTI provides a way to evaluate pre-symptomatic brain damage in people with high blood pressure in order to identify possible therapies to help control brain damage and reduce the eventual development of dementia,” commented Carnevale.
Although a significant amount of research has evaluated hypertension-related brain changes in grey matter, the team believe that identifying alterations in the brain’s white matter will provide an opportunity to identify the effects of high blood pressure even earlier than currently understood. While, DTI, or tractography, is not routinely used in medical practice the results may help to encourage physicians to consider brain damage when treating patients with high blood pressure.