PLEASE PLEASE consider the TCVM ***first*** -- you really don't need testing. It's going to be super inconclusive with something like this. EVERYTHING you are saying more and more says neural to me -- and so many things can contribute.
Did you realize that even silly small things like the flickering of a television, very common household clearers, and even dog shampoos sold right at the grocery store - ALL THESE can cause seizures in one form or another.
Very often seizures aren't the thrashing around/foaming at the mouth thing you'd expect. Any time an animal is really "out of it" mentally -- where you can't easily just call their name quietly and have them look at you immediately -- that can be a seizure.
I can *NOT* stress enough this does *not* have to be expensive. There are a ton of TCVM vets in Jersey (3 pages of them) -- from Cape May all the way north. Because a lot of south/central Jersey is pretty much farm territory there are MORE TCVM vets there than you'd believe. Please -- just go to that link http://www.tcvm.com -- go to the left hand side and plug in your zip code and see what you get. Look also at the Pennsylvania list -- there might be someone just over the border that would work for you since you're so close to Philly.
In your written list of what's going on -- think further back in the day.
1. Was the dog, that day, anywhere near a pine tree -- particularly close enough to get pine sap on it (or playing with pine cones).
2. Anybody clean that day with Pine Sol or any pine cleaner?
3. Anybody cook with rosemary that night? or could the dog have gotten into rosemary (it's a pine related herb)
4. Did the dog have a bath that day? get heartworm meds? flea meds?
5. WAs the lawn fertilized? mown?
6. Did your city spray for mosquitos or any kind of city spray or fly-over spray? (you may not even know)
7. Did a *neighbor* have their lawn treated/mown/fertilized?
8. Is it a particular night of the week? A particular TV show or commercial that may have been on (weird repetitive sounds, lights)
9. What phase of the moon was it? Full moon? nearly full? New?
10. Is there any sign prior that the dog is very tired? How about the dog's position? It can even be related to the dog sleeping with it's head ON something, or laying in maybe a typical, but potentially neck-stressing position. (or in a draft -- ANYTHING that might stress the cervical area).
My next questions would be about where the dog lies -- you might want to try a crate JUST for late evening "chill out time" -- you can put in a nice blanket or a marrow bone ... keep it a "good place to be" -- but it's also a safer place maybe
No vet is going to condemn a dog for something like this -- at least not a *decent* vet. But I can promise you -- a TCVM vet is gong to take this seriously. If you want to email me I can tell you pretty much what their costs might be and I suspect if they use herbs it could be a very easy not-expensive thing.
My very last suggestion may seem overly simple. But before you rise, have you tried calling her to come to you and having her "sit" in front of you? In other words -- get her up and **moving** so you KNOW she's awake.
I would likely try simply re-arranging things first ... either make her a new "bed" or buy an inexpensive one but re-arrange things a bit. First off -- I would either use a couple of baby gates (you can make them CHEAP with a slab of wooden lattice -- cut it in thirds and screw a piece of cheap molding to the top and bottom of each piece -- and suddenly you have three "baby gates" and you can prop them up or even hook/eye them together to make a 3-sided area that is a small "den" for her but provides a safety barrier until you work this out and find out the real cause.
Make the bed seem like some new terrific thing for her -- don't segregate her far away from you ... but arrange it so she's ultimately behind the enclosure when she settles to sleep. Then ... it will give you some bit of barrier for safety.
But please -- try the TCVM. There will be no big tests, no big expensive anything. Just the cost of the initial vet visit (which will be a couple of hundred dollars but they will spend a couple of hours examining her AND giving treatment). Beyond that will only be some herbs.
I'm going to ask Megan to jump in here -- Pirate seizes and often his seizures are nothing more than him acting "nervous" -- but they ARE seizures. But some of his were very similar to this -- and the timetable was VERY close. (and incidentally -- my "list" above? a good share of those things were things she discovered triggered Pirate! The rosemary in particular -- and there is rosemary in some dogfoods!)