Hello!
Thank you for asking on HCM!
Regarding your concern, I would explain that as this
artery was 100% closed, his brain has functioned without it during this time.
This has happened using the collateral blood circulation, which are small branches that connect different arteries in the brain.
It is true that when an artery is 100% closed, it causes a brain
stroke and there is no need to open it again, as the consequences are irreversible.
From the other hand, it happens during dissection of the artery that the blood flow may start again.
This is a good thing, because it helps the collateral circulation function better.
From the other hand, as there are dead brain cells, hemorrhages can occur in this damaged area of the brain.
That is why it is important maintaining a normal blood pressure and avoid possible spikes in blood pressure which can lead to hemorrhage.
Hope you will find this answer helpful!
Best wishes,
Dr. Iliri