Have the doctors tested your vitamin levels (Calcium, etc.), blood sugar around the time you've gone out, and electrolytes? With my daughter all of these are low and the way I understand when your calcium is too low, blood sugar, or electrolytes are too low you can have seizures. Then you can find out from your doctors if this is the problem whether you can supplement in some way to get these under control. I don"t know if any of this will help, but I thought I would just mention it.
God bless you.