Unfortunately, if it's an actual epileptic seizure, it would show on the scans. You might ask about an EMU (epileptic monitoring unit) stay to try and get a closer look.

You can also get a take home portable EEG unit. When I first started having seizures and we were trying to figure it all out one of the tests we used was the portable EEG. The Leeds are glued to your head as usual, and the Leeds plug into a small box with a strap that you can wear. I wore it at home for 3 days and found it much more convenient and cheaper to do it outpatient than inpatient.

I have epileptic seizures and they only show up on eegs about half of the time. It sounds like an EMU might do you good though.