My thoughts and prayers go out to your sister and her child.
my hubby and I were epileptic. he was epileptic for age of 2 to age 14. went through numerous tests and different heavy medications during those years. they never figured out why he got them. But he outgrew them. Me, I suddenly had a grand mal seizure when I was 18 after a serious migraine. I, too, underwent many tests and medications. But there seemed to be nothing wrong with my brain or its activity. After my 2nd grand mal seizure, i havent had once since then. its been 5 years. I'm still on medication but my doctor says that i may be able to get "weened" off of them in a few years.
When I was pregnant with my son, we were really worried that he would be epileptic because of the epileptic history in the family. Luckily he was born without any signs.
my hubby's former boss has a daughter who suddenly became epileptic at the age of 2 months. it was a very fearful and trying time for the family. I remember hubby telling me that the boss was greatly stressed and had very little sleep because his daughter would have numerous seizures. The cause was from the fact that there was a huge hole in her brain because that part never developed. She's now 4 years old, healthy and happy. unfortunately in her case, because her brain never developed in that one spot, she has a learning disability and she processes things slower than kids her age.
I do hope that your sister's child wont have to go through that. its hard on any parent who has to see their children in any sort of condition like that.