Deterioration in blood vessels in the brain is connected to the onset of neurodegeneration - which is an ongoing process, starting long before someone is diagnosed with dementia. It is one of the mechanisms by which brain health is connected to general health. Here, researchers shine a light on failing blood vessels in the brain: "A small amount of bleeding in the brain seems to be common among older individuals ... cerebral microbleeds are highly prevalent in the aging brain - and not primarily products of stroke-related injury, hypertension or neurodegenerative diseases such as Alzheimer's, as had been thought. ... Prior work relied on brain imaging to show cerebral microbleeds. But in this study, deep regions of the brain were closely examined under a microscope, and nearly all subjects had evidence of small areas of bleeding. ... [Researchers] studied postmortem brain specimens from 33 individuals, ranging in age from 71 to 105, with no history of stroke. Cerebral microbleeds were identified in 22 cases - all occurring in capillaries, the small blood vessels of the brain. This is a substantially higher rate of incidence than that reported in MRI studies, which have shown microbleeds in 18 percent of people between 60 and 69 and in 38 percent of those over 80. ... Results from [the] study also indicate that leakiness of brain blood vessels increases with age, [despite] the fact that a specific barrier (known as the blood-brain barrier) exists to prevent leakiness."