Abnormal EEG for a healthy 4-year old bpu

My healthy 4-year old boy had a seizure about 3 days ago.  On the ride to the hospital he had 2 more small ones in the ambulance.  He has never done this before.  He had a temperature of 102.5 when arrived at the ER.  The ER doctor thought it might be a febrile seizure....But, my son's peditritian said he was puzzled by the 2 more seizures in the ambulance.  All blood work and Cat scan came back normal.  Today we found out that the EEG had some abnormalities on the left side of his brain.  He hasn't had any more seizures and no more fever.  I'm scared and I'm looking for help and answers what this possibly could be.  He is acting normal.  

[nmom]

I just read your comment.  I have a healthy 3yearold boy who had a seizure in April, then a few more seizures.  The cat scan and blood work were normal, eeg came back with slight voltage asymmetry.  He's scheduled for an MRI next week.  He has also been fine ever since but I am so worried.  Have you found out any information?  My pediatrician and I think maybe it was a mild concussion (he hit his head earlier that day) and low blood sugar since we were on vacation and he was very active and had little to eat or drink all day.  Thanks for sharing, look forward to hearing from you.