Hypertension, or high blood pressure, is commonly diagnosed among the middle-aged and elderly population. In individuals aged 40-59 years, there is a prevalence of 54.5%. In individuals aged ≥60 years, there is a prevalence of 75.5%.
However, it is not common knowledge that reports indicate that hypertension occurs in approximately 22% of adults aged 18-39 years in the United States. Hypertension in young adulthood is defined as systolic blood pressure (SBP) > 130 mm Hg, diastolic blood pressure (DBP) > 80 mm Hg, or use of antihypertensive medication.
To study the impact of hypertension on the brain and cognitive function, researchers have relied on measurements of brain volume which assess the size of a person's brain. Loss of volume indicates brain shrinkage. Recent studies suggest that high blood pressure may be associated with lower brain volume, which in turn has been linked to reduced cognitive function. For example, research has shown that brain shrinkage is a normal part of the aging process, and it has been associated with memory loss. Using magnetic resonance imaging (MRI) to measure brain volumes, Shang et al. (2021) found that hypertension diagnosed in young and middle-aged adulthood is associated with decreased volumes of the whole brain, gray matter (outermost layer of the brain involved in processing sensory signals, e.g., pain or pressure, and releasing new information to allow control of movement, memory, and emotions), and white matter (deeper tissues of the brain involved in relaying messages between brain regions) found in later years, i.e., when individuals with early onset hypertension are around 45-80 years old.
The study also revealed that individuals diagnosed with hypertension at ages 35-44 years are at an increased risk for development of non-Alzheimer’s dementia, i.e., incident all-cause dementia and vascular dementia. This latter disease, vascular dementia, is caused by conditions that damage blood vessels in the brain, interrupting the flow of blood and oxygen to the brain. Changes in white matter are common in the brains of individuals with vascular dementia.
These reports suggest that the prevention or treatment of increased blood pressure in young to middle adulthood may help to reduce the risk for the development of non-Alzheimer’s dementia.
Another investigation, Hu et al. (2022), demonstrated that trajectories of blood pressure that begin at moderate and elevated levels and continue to increase during early adulthood are associated with changes in white matter volume as early as midlife. Although no underlying mechanism linking the age at diagnosis of high blood pressure, brain volume, and cognitive decline has been clearly identified, these reports suggest that the prevention or treatment of increased blood pressure in young to middle adulthood may help to reduce the risk for the development of non-Alzheimer’s dementia.
The potential role of high blood pressure has been addressed in lawsuits alleging cognitive impairment or decline. See Hoque v. Barr, 824 Fed. Appx. 21, 24 (2d Cir. 2020) (in which the petitioner argued his high blood pressure was a factor for his alleged memory loss); Stephens v. McDonough, 2022 WL 949810, *1-2 (Vet. App. 2022) (veteran argued that his high blood pressure was a cause of his alleged short term memory loss); Staples v. Wilkes, 2020 WL 1518223, *2 (Vet. App. 2020) (VA neurologist “diagnosed mild cognitive impairment likely due to cerebral microvascular disease, noting Mr. Staples's history of high blood pressure”). Courts have not directly considered early onset high blood pressure in younger adults as a contributing factor to cognitive decline, such as non-Alzheimer’s dementia, but they seem generally open to considering it as such. Supra.