Of course I cannot give medical advise so these are just my personal opinions:

I would get on the books for another appt, but if the events get worse or he appears to be in distress (which he doesn't look to be now), then by all means don't wait. Mom's have good instincts for when to throw in the towel. I think you will know what the best call is based upon what you see and feel.

You said the EEG was coming up...when?

Can he relate to you anything he feels during these times? Does he feel tired, have any chest discomfort or strange feelings in his chest (pressure, shaking/jumping/fluttering), any breathing changes, etc? Have you checked his pulse during these times for high or low rates?

Have you checked side-effects to any of his meds?

BTW, he is a handsome young man!!!