My son had a normal eeg before taking phenobarbital on a daily basis. his eeg for the next two consecutive years became abnormal. why is that so?

Abnormal EEG: I suspect the first EEG did not appreciate the seizure activity until a later date. There obviously was some clinical reason to start Phenobarbital, and it it safe to say your child will remain on medication until such time as the EEG is normal for several years. You should make sure the PB dose is adequate, as the abnormal EEG could be telling you your child needs a higher dose... Check w/ Neuro