I Have A Son Who's 29 Years Old And He's

I have a son who's 29 years old and he's been seizure free for 20 years now. last march he had grand mall seizure and hes been on different meds and nothings working. where can I go to have him tested again. hes having them really bad at night. and tonight his 6 year old son witneested tonight. we need answers cause its not healthy for him. and we are starting to get scarred for him. please help. live near greeenbay wi.