Patients with hypertension and diabetes have slower articulation between neurons and blood microvessels, even before they have brain damage or stroke, according to researchers at the Faculty of Medicine, University of Porto (FMUP), Portugal.

One of the coordinators of the work said that neurological activity may be affected and occur at a reduced speed "sluggish, slow and less intense" in patients even "before they have brain damage, vascular dementia and stroke. This significant joint deficit or dysfunction is detectable even without any symptoms of cerebrovascular disease.

Elsa Azevedo, a US researcher, said that the connection between neuronal activity and vascular response is essential to ensure normal brain function.

"Normally, it is necessary to increase the blood supply to the brain areas that are most active at a given time, and this is achieved by the physiological mechanism of neurovascular coupling, that is, of articulation between neurons and the blood vessels that supply them," he explained.

The discovery is "promising", but the researcher has some reservations because more studies are needed before it can be used routinely in clinical practice.

"The goal is to go further back and understand what is at the root of that brain damage so that you can correct and prevent strokes," he stressed.

Patients with hypertension who had never had a stroke participated in the study, and were subjected to non-invasive imaging tests, including transcranial Doppler to analyze the main mechanisms regulating cerebral vasoreactivity and magnetic resonance imaging to assess the volume of white matter lesions in the brain.

Doppler is a non-invasive test to estimate the flow of blood through blood vessels using ultrasound that is focused on blood cells.

During visual stimulation, the researchers found that hypertensive patients have a slower acceleration of blood flow in the artery supplying the visual cortex, a slower response to increased stimulus needs, and less flexibility in response compared to healthy people without hypertension, she said.

In patients with hypertension and diabetes, the results were even worse, which points to early deficits in neurovascular coupling, prior to the onset of symptoms of cerebrovascular disease," he added.

Thus, the study shows that diseases such as hypertension and diabetes can negatively affect the brain even before the onset of cerebrovascular diseases such as stroke or cognitive changes.