I don't have any personal experience with any of this. Just a thought from reading what you described.

If it lasts an hour, then is it possible to get the dog to a vet while the symptoms are happening? Just show up, no appointment, don't call first, just get her in there for someone with some medical training to observe? Maybe your vet, maybe another vet, or a vet specialist or emergency vet?

If you consider doing this, be CAREFUL. Some of the types of illnesses you are considering, the dog may bite you, not knowing it is you. Getting the dog out of the house, into the car, into the vet, be careful. And in the vet waiting area, be wary of others who may be there, human or pets.

And pleae let us know how things develop! Wishing all the best for you and your dog.
Sandra