Professor Matthew Kiernan

So little parts and little holes start developing, small strokes, micro strokes at a very molecular level.

So you wouldn't see it if you had the brain in front of you, but if you put it under a microscope, you'd see it.

And you probably can't detect it either while someone's alive.

Unless there's a certain amount happening, like a volume.

It's a volume effect.

So we start to see it with MRI scans, but by that stage, it's more often than not more severe.

More problem.

So right at the beginning, and that's the trouble.

We don't know when this begins.

So it could be beginning 20 or 30 years before the patient manifests any symptoms.

Reduction in blood supply.

And it's really been driven, the understanding through vascular research, so cardiovascular health, so understanding that the wall of the blood vessel gets thicker, the sort of the lumen or the hole in the middle gets smaller, less blood gets out there.

Sometimes the vessel actually breaks apart a little bit.

A bit of ooze and blood and proteins escape into the brain.

That's the process.

And that happens in general areas.

Interestingly, one of the key problems that you see is people start falling over.

And everyone thinks, oh, falls are normal.

No, if you have a fall, that's abnormal.

I mean, obviously, if you have a fall, you're running and you trip on a gutter, that's understood.