Microvascular contributions to dementia: exploring the role of blood-brain barrier leakage in cerebral small vessel disease and Alzheimer disease

The blood-brain barrier protects our brain cells through the selective exchange of substances between the blood and the brain. This dissertation used magnetic resonance imaging and microscopy to measure blood-brain barrier damage caused by substance leakage from the blood in people with cerebral microangiopathy (damaged blood vessels in the brain) and people with and without dementia and early-onset dementia. We found a correlation between blood-brain barrier leakage and age, past cerebral infarctions and other signs of vascular damage in the brain, which was linked to slower information processing. Blood-brain barrier damage was also associated with minor intracranial haemorrhages. Protecting the blood-brain barrier may slow brain damage and the development of dementia.