There should be instructions about other things to avoid for how long before the test (e.g. chocolate has caffeine). Ask for full patient instructions (if they don't have any, would really wonder about the quality given your prior experience).

Just a note that different kinds of seizure issues have different likelihood of showing up on EEG - absence (and often other generalized) patterns are usually easier and focal is harder (bad smell is a focal seizure, staring can be absence or focal). One can have both focal and generalized types or just one type.

What lasted all of 10-20 minutes? The sleep deprived EEG was longer as the person actually sleeps during the ideal test, our child's last one was ~3 hours.