Tam.
I'm going to add one more thing to this idea of mine. It is how the synapses work. A lot more information enters our brain than needs to or that we can process so a good bit of it is rejected. The synapses have multi ports for information and they do not all open to pass on the information. They pass on related information and reject what you don't need. This is how medication works. It slows down the information flow and some times you get a fuzzy not quite there feeling. I also figure this is where weird dreams come from. The random mixing of unrelated information.
So to get back to the attacks. And I think this probably does happen more when you are tired or resting because the information flow is already less. Take your tingle. You register the tingle but not why because you are busy doing some thing else. Watching a movie. The tingle is something foreign so your fight or flight system springs into action to check it out. Shutting down all unnecessary information and going into hyper-vigilance. Or in our case over hyper-vigilance since if you have had a panic attack before you have the tendency to have another.
So instead of calmly looking at why you have this tingle you jump up to escape. Two roads here. You took the wrong one is all.
I'm taking a medication right now that does this to me. (same effect just more intense because it is a side effect of the medication) I can be calmly watching a movie or worse yet sleeping and something will wake me. Often it was so quick that I don't register what it was, it just was. This may be why it is thought there is no reason for the panic. I start to go into panic mode, I start to jump up, but then because I have taught myself to do this, I dig for the reason I'm panicking. (like the ten questions) I either come up with "there is nothing there" or "it is just mixed information" Both of no concern and I can tell it to go away by accepting, First that it happened and second that it is nothing to be concerned with. Fight or flight shuts down. It is still in the background for a while like a top slowly spinning down but it is harmless because I know it is and believe it is. Over time this winding down has got shorter and some times doesn't happen depending on how close the trigger was to one of my previous panic triggers.
In your case, the tingle is too close to your fear of death in the form of an aneurism.
So this is why I say there is always a trigger even if it happens so fast you don't register what it was. Or you were asleep and it woke you but didn't register.
This is just how I see it, how it happens to me, and how I get rid of it.
I will admit that when I get weird pains the first thing I think of still is that I'm dying. But by questioning them I keep from going into panic mode.
My therapist said that if attacks are the side effect of a medication (in my case an antibiotic) that it takes medication to get rid of them because they are so strong. And for a while it did take half a valium. But lately I have been able to tell them to go on my own. Still if they won't go I use the valium to slow down the information flow.
Here for you,
Davit