Sometimes, even though you feel your seizures are in control, it still positive that there is a very mild activity in your brain . Other times they can’t read a thing with no results.

If that happens, they are better off doing a 3-7 day EEG. Then they can reduce your meds ,so many times a day trying to get big result from you seizuring.

The EEG reads your brain waves. You don't exactly have the physical
siezure but your brain waves will start reacting to the flashing lights in a irrational manner. Showing seizure activity.
Just you thinking about the EEG will cause siezure activity.

Hi Emma I am in the UK I had a EEG a little time ago like people say it's brain patterns they said to me but the brain pattern seem different on the left hand side that's how they know I have epilepsy

they do the eeg test again with more hours and/or less meds. they have to get a seizure during the eeg.

Because of the events that are performed during the test which is routine. They will basically record your brain movements during the test as they ask you to relax during the test. Some people fall asleep like me and they had to wake me up to finish the test. Some folks are nervous about it which isn't good because nervousness can create seizures or auras. Best of health to you!