I'm sorry to hear about the poor wee cat.
My Zara, a black DLH, is epileptic too. She has one 15mg dose of phenobarbital a day and it stops all seizures, thank goodness. If we miss a dose, she has petit mal ones, and freaks out a bit in between them. You can see a huge difference in her behaviour: she sort of has a mad few seconds, gets scratchy and irritable with people, freezes, and then goes on with her day. Which basically means: don't miss a dose. Her grand mal seizures have body stiffness mixed with traditional "fitting" episodes, and foaming at the mouth. Like Splodge, she is very affectionate after. Thankfully, it's been a couple of years since she last had a grand mal seizure.
She was diagnosed with epilepsy at around 2 years, and she's just passed her 6th birthday now.