Greater Incremental Damage to Brain Tissue Means a Greater Risk of Stroke and Death
It shouldn't be too surprising to find that people with greater levels of minor brain damage are at greater risk of stroke and death, as noted by these researchers. Blood vessel integrity deteriorates with age, and as a result, many tiny areas of damage accumulate in the brain where small blood vessels suffer breakage. This destroyed tissue contributes to cognitive impairment, one small disaster at a time, all of them going individually unnoticed. The amount of this brain damage in any given individual is a reflection of the degree of deterioration that has occurred in blood vessels and other important structures, caused by underlying forms of cellular and molecular damage that accumulate throughout the body. Since aging is a global process, more damage in one location usually correlates well with more damage everywhere:
The researchers analyzed brain magnetic resonance imaging (MRI) data from nearly 1,900 individuals participating in the Atherosclerosis Risk in Communities (ARIC) Study who were 50 to 73 years of age with no prior history of stroke, tracking their health over about 15 years. Risk of stroke or stroke mortality in people with small lesions was three times greater compared with people with no lesions. People with both very small and larger lesions had seven to eight times higher risk of these poor outcomes."The lesions on the brain imaging were very small, less than 3 millimeters, and are typically ignored in clinical practice. This is because we have been uncertain as to their meaning; no studies have looked to see if these very small lesions are related to important clinical outcomes. Our findings suggest they are at least as important as 3 millimeter or larger lesions that are typically considered abnormal, even in absence of other lesions. We know that modifiable risk factors like hypertension and diabetes are associated with the larger structural changes in the brain, and those larger lesions are not only associated with stroke risk but with mobility impairments and cognitive impairments as well. Ongoing trials may determine whether treatment of risk factors, like high blood pressure, reduce the incidence of these lesions, stroke and associated death and disability."
Link: http://www.sciencedaily.com/releases/2015/07/150706183247.htm