Excessive & Abnormal Brain Blood Vessel Formation Linked to Alzheimer’s

A new study shows that altered permeability in the blood-brain barrier is a key factor associated with amyloid beta excess. Previously it has been shown that leakiness of the blood-brain barrier allows substances to enter the brain that provoke brain inflammation and consequent excessive production of amyloid beta. This study adds a new twist, actually showing that amyloid beta acts on the blood-brain barrier to make it more permeable. In essence, this now becomes a chicken-and-egg issue and means that once the problem gets going it is likely to become self-perpetuating.

The researchers found that excessive levels of amyloid beta were associated with excessive levels of new and abnormal blood vessels lining the blood-brain barrier. These new blood vessels were not of proper structure or function, thus they allowed even higher levels of irritants into the brain, provoking even more damage. This was documented using specialized gene knockout animals and this excessive level of new blood vessels was confirmed in humans via post-mortem brain analysis.

As I reported in my previous article, there is new evidence of microscopic blood vessel damage at the blood-brain barrier in individuals with Parkinson’s-like symptoms, a finding that would surely be found in issues of cognitive decline if researchers every get around to testing for it. A natural response to such blood vessel damage would be to try to make new blood vessels. Interestingly, this same sort of response actually goes on in the blood supply within large arteries and is responsible for atrial fibrillation and arterial plaquing.

Here we see the process of abnormal blood vessel formation associated with Alzheimer’s and cognitive decline. It is likely that the process is being driven from within the brain as well as from problems in the vascular system. The take home message is that any person with any level of declining memory or cognitive ability is likely to have structural malfunction at the blood-brain barrier and everything should be done to interrupt this nasty catch-22 that is associated with declining nervous system function.