Why vascular health may hold the key to cognitive function
When most people think about vascular health, the heart typically comes to mind. Controlling blood pressure, managing cholesterol and staying active are often seen as ways to stave off heart disease. But maintaining a healthy vascular system is also critical for another essential organ: the brain.
“Vascular contributions to cognitive impairment and dementia are very common,” said Sudha Seshadri, MD, DM, founding director of the Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases at UT Health San Antonio. “Over a lifetime, nine out of 10 people in the U.S. will develop hypertension, so the risk of developing damage to the brain because of injury to the blood supply is extremely high.”
Vascular cognitive impairment and dementia, or VCID, is the second-most-common cause of dementia after Alzheimer’s disease, often overlapping with it. According to the Centers for Disease Control and Prevention, it accounts for 5% to 10% of dementia cases on its own, but experts say that in mixed cases, vascular injury plays a role far more often.
“The most common form of dementia isn’t just one type — it’s a mixture. It’s what we call multiple etiology dementia, and vascular injury is the most frequent contributor to that mix,” Seshadri said.
“Even when someone has Alzheimer’s disease, we still need to ask: Are there vascular contributions that we can manage? Because treating those may slow progression more than any single drug we have right now.”
Signs of vascular injury to the brain
Symptoms of VCID differ from those of other dementias, like Alzheimer’s disease, and they present in a number of ways depending on what part of the brain is affected by the vascular injury.
“Someone who suffers a big stroke could have critical regions like the thalamus knocked out. That area controls motivation and planning,” Seshadri explained. “Or, someone could have a series of smaller strokes that collectively impair function. You might see signs like slowed thinking, trouble with language and executive function and physical symptoms like difficulty walking — features that differ from the typical early symptoms of memory impairment seen in Alzheimer’s disease.”
Other signs include emotional changes, such as inappropriate laughing or crying, known as pseudobulbar affect, and a higher prevalence of depression.
“These clinical features can give doctors clues that vascular issues are involved,” Seshadri said.
Advancing care through AI
In addition to how clinical symptoms present, advanced imaging can help clinicians diagnose and detect brain changes earlier and more precisely.
An artificial intelligence tool developed at UT Health San Antonio can accurately count brain lesions on MRI scans within seconds, helping neuroradiologists evaluate patients’ brain diseases at earlier stages. With this technology, doctors are able to not only see the signs of vascular injury like microbleeds or enlarged perivascular spaces with the imaging, but also quantify the imaging.
“We can quantify changes to the brain, the number, the intensity and the location of the changes in the brain,” Seshadri said. “All this information is crucial to helping our understanding of what’s causing them, which can lead to developing better treatments.”
Small vessels, large damage
While a large stroke can cause devastating damage, the more common contributor to vascular injury is not from the large arteries, but from cerebral small vessel disease, which affects the tiny vessels deep in the brain, Seshadri explained.
When these small vessels become obstructed, they can impair oxygen flow, causing numerous small, silent strokes. Obstructed small vessels can also burst, causing small hemorrhages, or microbleeds.
Common causes for cerebral small vessel disease are hardened arteries, or arteriosclerosis, and cerebral amyloid angiopathy, which is when amyloid protein — the same found in Alzheimer’s disease — deposits in blood vessel walls, causing them to leak or rupture.
While injury to small vessels doesn’t present as dramatically as having a large stroke, over time it can lead to widespread structural damage.
“Some people can have hundreds of microbleeds in their brain,” Seshadri said. “And as you can imagine, it causes a lot of disruptions to a person’s daily tasks and functioning.”
Findings from the Nun Study, a landmark study analyzing more than 30 years of aging and dementia patterns of 678 nuns from the School Sisters of Notre Dame — now housed at the Biggs Institute — discovered the integral role of damage to the small vessels of the brain in developing dementia.
Researchers found that among elderly nuns whose brains had equal levels of amyloid plaques and tau tangles — the key features of Alzheimer’s disease — those who had a large stroke were five times more likely to have dementia. But those with the small, silent strokes caused by cerebral small vessel disease were 20 times more likely to have dementia.
“Because of this finding, today there is a lot of emphasis on what is causing this small vessel disease and how to treat and prevent it,” Seshadri said.
Prevention begins with awareness
Fortunately, there are many lifestyle factors that, when managed, can greatly reduce a person’s risk of developing VCID.
“The same risk factors that lead to heart disease, like high blood pressure, diabetes and inflammation, are heavily involved in brain injury, too,” Seshadri said. “So, managing blood pressure, staying physically active and avoiding smoking can all reduce your risk.”
Seshadri emphasized that maintaining good vascular health is always a good idea, no matter the condition.
“Even if someone has Alzheimer’s or a different type of dementia, hypertension adds to more risk and more injury,” she said. “So, regardless of whatever type of dementia someone may have, it’s important to remember that there could be vascular factors that have the potential to be managed, which can slow down that disease.”
A new era of dementia care
In South Texas, where dementia rates are higher than the national average, specialty care and focused research efforts are critical for the health of the community.
“While we don’t fully understand why South Texans are at greater risk, we do know that this region has higher rates of vascular risk factors like diabetes and obesity, which contribute to vascular dementia,” Seshadri said.
At the Biggs Institute, vascular cognitive impairment and dementia are a key focus for clinical care, community outreach and major research initiatives. In addition, UT San Antonio’s Biggs Institute, in collaboration with UT Rio Grande Valley, holds the premier designation by the National Institute on Aging (NIA) as an Alzheimer’s Disease Research Center (ADRC). The South Texas ADRC is one of 33 funded by NIA at major medical centers across the United States and is the first one in Texas.
The recent opening of UT Health San Antonio’s Center for Brain Health in December 2025, which houses the Biggs Institute, will further bolster the university’s efforts to serve the community. The new facility advances comprehensive brain health research and provides innovative expert care for patients with a wide variety of neurodegenerative diseases, movement disorders and complex neurologic conditions.
The center’s current and future research efforts will benefit from significant recruitment of South Texans into clinical trials, helping to expand the nation’s understanding of how brain-related diseases affect populations in this region. The center also serves as a training venue for medical residents and postgraduate trainees, ensuring the future of sustained neurological care for the community.