Hello and welcome to the NeuroTalk support groups!
For a start, here is the link to the
Epilepsy Forum
You should perhaps talk with the Doctor who knows your son's medical history and voice your concerns about the future and ask for a referral for NeuroPsychological testing. I'm not in your country but I do know that where I am, we need a referral. Sometimes they're done by private Psychologists and sometimes they can be done at big institutions such as Universities. I'm not sure if it's the same in the US but imagine it is. If your son sees a Psychiatrist, then I'm sure she/he would be able to give you advise as well.