What causes that? High blood pressure?
I am not sure of all causes. In my husbands case I think it was a combination of things. He had an artificial aortic valve so he had to be on blood thinners. He takes blood pressure meds so his blood pressure was stable, but he was quite a bit over weight. He had been doing some heavy lifting and I think the strain in lifting put pressure on his brain and caused the vein to break. The next morning I noticed him walking funny and grabbing onto the kitchen counter. He survived and was able to drive again but never the same as before.
A year ago that artificial valve had to be removed because scar tissue was growing around it and narrowing off the opening. This time they put in a pig valve and his Blood Pressure meds were cut back and he no longer has to be on blood thinners. But now he is diagnosed with Parkinsons Disease. He has had a lot of things going on in his life, but he takes it in stride.
I got to UMMC hospital in Baltimre within a few hours (this was, I think a very key factor in recovering) and spent two weeks in their Neural-ICU, pumped full of medicines to relax the blood vessels for stroke prevention. After they found its location in my brain via Angiogram they hit it with the "Gamma-Knife" which got rid of it, and I'm fully recovered now except for some short term memory loss. I was really pretty lucky, and if it hadn't been so scary it might have been fascinating.