I too had seizures before surgery. In fact, that is how my AN was diagnosed,, through MRI for my first seizure. Dr. came back and said ," don't know why you are having seizures, but you do have a brain tumor"! Imagine my surprise! That was 7 years ago, had about 8 total over a three yr period before I had surgery in 2011. To this day, neurologist says they aren't related. But I never had seizures until this tumor came along. So,,,,,, yeah I think they can be related...but I'm no Dr. However,,, I don't think all Drs know "a lot" about these tumors either.
I had a similar "episode" as your husband. Not a lot of tremors as usual seizure,, mostly a "sense" it was going to happen, a vertigo type dizziness, even if sitting, and poof,,,out I'd go..usually only lasted a few minutes if that and I'd come out of it. I never vomited though,, but did have the open eye stare.
No one suggested heart problems for me.. I have a healthy heart though as documented by cardiologist.
Does sound similar to mine. But few others have mentioned it on here,, if any that I can remember.
Good luck,, I don't know either whether you are "barking up the wrong tree" with surgery,,, have you had a second opinion for the surgery?? There are several Dr.s who will give free phone consults if you send a copy of MRI .... just a thought. ...
Let us know how he does,,,,, Jane