@suesa is amazing
You are a scientist, plus you are a graduate of science (natural science).
I have several pairs of your post and pointed to it.
But not what I mean. Before going up the stroke there must be a cause.
I have studied in science as well. The cause of the stroke is due to narrowing of blood vessels leading to the brain so that the blood and oxygen intake to the brain decreases.
Thus the various occurrences of biochemical reactions that make brain blood cells to die.
Is that right @suesa, thanks a great job.