Well he will always have seizures, but with medication they should be able to control it. Just make sure that he goes in for all the tests he is asked to. I know there will be follow up blood tests that will check for certain antibodies.
Were they ever able to tell you why his eeg and scans were normal for so long and then changed? My sister has been having seizures for 7 months nnow and all test are normal but they are becoming more frequent and severe. What doctors were able to help him (neuro, biophysiology)?