I have the same surging blood pressure occasionally as I wake up. I had an acute case of it for two months this year, where it was a multiple, everyday episode. It made me very sick and I missed some work days. I've had it for about one year now.
My BP will usually be 99/57 at full rest, awake. When the surge happens, I will wake up very suddenly with that surging feeling and have BP of 148/92 or more, spiking further when I get up. I wind up shivering cold with the shakes after a few minutes (5-20mins) - my body temperature drops.
Early on in these extreme episodes, I would have a rapid pulse that went over 100. It was a full throttle panic attack, but none like I had ever had before. I too truly thought I was going to have a stroke and went to the emergency room a number of times. It happens during sleep, between 4am - 9am for me. It has also happened just before & just after waking up during my two months of intense, daily episodes.
Something hormonal or nerurological is happening, beyond the possible panic attack/pre-menopausal diagnosis. It is a rather severe reaction. It physically hurts and is disruptive to somebody who is in relatively good health - and for one who works at being healthy (me).
I take Paroxetine - that helps - but I still don't have a sufficient answer on the mechanics of this problem, or a name for it. The Paroxitine doesn't hinder the waking BP spike from cropping up a couple of times a month, but it does help quiet the panic reflex.
We know that beta blockers quell the high blood pressure process for some cases, and how it does that. I think this 'blood pressure spiking condition' needs more explanation in it's relationship to panic disorder or whatever it is really related to.
I think it is a dangerous condition. I would love to have some better explanations about why this happens.