you can do to make the collaterals work less well like smoking cigarettes will block up the collaterals having high blood pressure high cholesterol will block them up but you're kind of born with a set of collaterals so one of the things that you can imagine is since these blood vessels go to different regions of the brain the symptoms of the stroke are going to be quite different depending on what blood vessel is blocked so we'll talk a little bit about that first we'll show a little bit more detailed picture of what this Sokolov