The unusual structure of blood vessels in the brain is not only for supplying nutrition and oxygen but also maintains the delicacy for its optimal functioning. Recent studies indicate that the abnormal growth of blood vessels, especially in the forms of malformations or unusual formations of the vascular structure of the brain, may act as a major early indicator of cognitive decline, especially in diseases related to dementia and Alzheimer’s disease.
Though the idea that brain vascularity might help predict cognitive health is not new, that active area of research is making clear the ways such abnormal growths may serve as an early warning system, long before obvious cognitive impairment arrives. This is the finding that offers early detection and intervention possibilities, thus offering new hope for the millions at risk of cognitive diseases.
Blood Vessel Growth and Cognitive Impairment
Specifically, cognitive impairment, especially dementia, is diagnosed at a rather late stage when irreparable damage has already been done. But then again, scientists are beginning to unravel how the blood vessels of the brain may be linked with cognitive health. Abnormalities in the blood vessels of the brain-the overgrowth or misrouting of blood flow-can potentially affect the brain’s ability to function properly. These changes may trigger an avalanche of problems that disrupt signaling in the brain, leading to memory issues, confusion, and other cognitive difficulties.
Research into the contribution of brain vascular malformations has revealed one shocking trend-that in the early stages of cognitive decline, the brain may actually grow abnormal blood vessels, rather like those occurring during the earliest phases of brain development. This, in turn, supports the concept that when this “embryonic” structure of the brain’s vascular system starts to develop, cognitive problems are well on their way.
Of the vascular disorders, AVMs are most associated with abnormal growth of blood vessels, wherein blood flows directly from the arteries to the veins without passing through the capillaries that normally regulate blood flow. This disrupts normal functioning of the brain and, consequently, may be accompanied by disturbances in memory, processing speed, and even motor skills.
Recent evidence has pointed to a leading role of the endothelial cells, which line blood vessels and control interactions between the circulating blood and surrounding brain tissue. In normal physiology, these cells participate in the maintenance of integrity within the blood-brain barrier that protects the brain against toxins and pathogens. With pathological neovascularization, these cells may begin to assume behaviors that promote disease development.
A Breakthrough in Brain Vascular Research
A big leap in understanding this phenomenon came from an international consortium of researchers that mapped the vascular system of the brain at single-cell resolution both in early development and in disease. The unprecedented study, which analyzed over 600,000 isolated brain cells, showed that blood vessel growth in the brain, once thought to cease in adulthood, may actually be re-activated under certain conditions. These include not only brain tumors and vascular malformations but even the earliest stages of cognitive decline.
Interestingly, the researchers found that when blood vessel growth occurs abnormally in the brain, it activates a biological response much like what happens during early brain development. Such a reactivation of vascular growth pathways does not happen in the adult brain, suggesting that these vascular changes can be an early warning for impending cognitive decline.
The vascular system of a developing brain is highly dynamic, growing and evolving continuously to meet the needs of the growing tissue. These growth pathways are for the most part quiescent in the healthy adult brain. In disease states, such as cognitive decline or vascular malformations, these growth pathways are reactivated, enabling the formation of new vessels in abnormal patterns.
Early Detection and Therapeutic Implications
The biggest consequence of this might be the chance for earlier diagnosis. At the moment, cognitive impairment is diagnosed too late when huge damage has been made and very often until symptoms become self-evident. Scientists consequently hope that through focusing on the vascular changes in the brain, ways to detect the abnormal growth of blood vessels can be developed long before cognitive decline reaches a point of irreversibility.
While this vascular change is of concern, the hope is that early detection may enable treatments for patients to slow or even reverse the course of cognitive diseases. Some treatments may involve targeting the molecular pathways driving the abnormal blood vessel growth or finding ways to stabilize the blood-brain barrier, preventing further damage.
Moreover, the study of the changes of endothelial cells in response to disease can allow the formulation of therapeutic strategies aimed at restoring normal blood vessel function in the brain, either by interventions that correct the vascular abnormalities or even in the development of drugs that block the pathological signaling pathways responsible for promoting these growths.
Researchers are also investigating the possibility of combining vascular therapies with treatments that target the immune system. The theory is that enhancing the brain’s immune response while simultaneously stopping the abnormal blood vessel growth could provide a potent therapeutic combination, especially in early-stage cognitive decline.
A Growing Area of Research
The connection between blood vessel growth and cognitive impairment is still in its infancy, yet the research moves at a rapid clip. A better understanding of how abnormal vascular changes drive cognitive decline may someday lead to revolutionary diagnostic tools and therapies that can alter the course of neurodegenerative diseases.
Given the complexity of the vascular system in the brain, researchers in these studies aim at the creation of full databases of the activity of the blood vessels, especially during the different stages of health and disease in the brain. Studying these patterns is bound to give them a better picture of how vascular diseases like Alzheimer’s or vascular dementia get started.
And even though a great deal of research was required further into the mechanisms leading to this discovery, yet that begets the hope for an early intervention in cognitive diseases. In fact, the promise is towards millions of people who would gain from such insight one day into the fight against cognitive decline in advance.
With increased understanding of the vascular system of the brain, these blood vessel abnormalities may prove to be other than a symptom-an early warning system. The good news could be that by the time such changes are detected, early medical intervention can significantly improve the outcomes for patients with cognitive impairment and change how we approach neurodegenerative diseases.
