cat seziures

I have a black long hair cat named Raven who is about 11 yrs old.. Shes always been very reserved and most people dont even know I have her cause she stays out of site.. she has her spots she lays at and her routines and shes never been a problem.. one of her places she sleeps is in on the corner of an accent table in my dining room.. One day a couple of weeks ago I was sitting in my living room and heard a thud.. then Raven started crying.. not like she was hurt kind of cry just sorta yowling.. I got up and found her sitting on the dining room floor with her face covered in what looked like spit up or something from from her stomach ,like she has scarfed up a fur ball or something but I didnt see a fur ball.. she quickly calmed down, I cleaned her up and everything was fine.. Last night she was sleeping with me and I was suddenly woken up by her running over the top of me howling at the top of her lungs like she was being chased by something.. she ran over the top of me, on to the top of Graces kennel, then fell to the floor between the kennel and the wall.. Im scrambling to get the lights on and trying to figure out what in the world was going on.. When I finally found Raven( I had thought shed run out of the room) it was obvious that shed had a seiure of some kind.. her face was coverd in the same fluid again and she was dazed and confused ..when I looked at her it was like she didnt see me. her eyes were dilated. After about a min her eyes refoucused on me and she quickly calmed down.. She let me pick her up and clean her face. Then she ran to her dish and gobbled up some of her food like she was starved.. Ive been around other cats that have had seziures before and the vet said that unless he sees her have one theres not a lot he can do for her.. anyone else have to deal with anything like this??? suggestions for me?? do you think its age related?? she a strickley an indoor cat and Ive not changed anything like her food or litter. I had gone out of town for a few days but shes never gotten upset when I did it before.. While she loves attention when SHE wants it the rest of the time shes very quiet.. I recently bought some organic catnip and gave it to both my cats.. they hadnt had it in a long time, both insidents happened after they had been given it but not like right after They get it about once a week.. maybe its related to whats happening? Although Canyon ,my manx is just fine...
any comments or help will be greatfully appreciated