L.R.
Allison, please, please get solid, real, reassuring medical information. You must talk to your son's doctors in great detail about what epilepsy is, and what to expect day to day, and how to cope. You must not sit home and worry -- please get out there and get informed, not via the internet with every crackpot crazy theory but through doctors who are experts. If your child's diagnosis is from the regular pediatrician only, you should see a specialist in epilepsy who can talk to you about living with it. Information is power. Your son deserves a childhood, and so does your other child; you know in your heart that you can't keep them home forever.
Also -- this is really crucial -- you need support not from Mamapedia moms but from parents of children with epilepsy, parents who have been where you are now! Please go to the web site www.epilepsyfoundation.org and connect with people who KNOW what this is all about. There may be family support groups that meet in your area, where you can learn from other families who have kids with epilepsy. This is a condition that CAN be lived with and controlled, but only if you start reaching out for help.
The same goes for the other tests he has had -- please don't let doctors just throw things at you; be aggressive and ask question after question and ensure they talk TO you, not AT you. Be sure your husband comes to every doctor meeting so he too is fully informed and can ask questions. You must not handle this alone.
I'm very sorry about your nephew's condition. But you do know, logically, that meningitis is a totally separate thing from epilepsy; seizures were involved in both cases but your son's seizure was utterly unrelated to your poor nephew's illness. THat doesn't make it less scary for you right now, but the way to fight the fear is to be very bold and assertive and get information from doctors and families.
Please let us know soon that you contacted the Epilepsy Foundation and got into a parent support group!!