Cat Seizure

So I think Puma had a seizure yesterday. I've never seen a cat have a seizure so I'm not entirely sure, but that seems like what it was. I was reading to Ammon in the living room and heard a noise on the stairs. I thought the cats were just play fighting like they do a lot, but then Puma just started tumbling down the stairs. Nala stood there looking confused and concerned while he fell all the way to the bottom and then took a few dizzy steps and sat down by the chair I was in. His head kept going back and forth and when we tried to hold his head still, his eyes would go back and forth. It was the strangest thing! Finally after about five minutes his head stopped moving and he slowly got up and walked away. Thankfully he has been fine ever since. I called the vet and they couldn't fit him in until next week. I hope it is nothing serious because I really can't afford to fix a cat right now!