Seizure?

Henry just had what I think may have been a seizure, very suddenly curling up on his side (I mean with his nose going towards his tail), then went round in circles, then staggering around. The vet said seizures were jerky and I'm not sure that's quite how I'd describe it, and he wasn't totally unaware the entire time I don't necessarily think, so don't know if it was or not. I gave him a cranberry and he ate it, while it didn't last very long, he seemed to go back to normal and then not right, not a seizure exactly but seeming out of it, lying flat again. He went back and forth between those states and is resting now. It did look like what I witnessed before after I seemed to have concussed him, so don't know if there's a connection (of course feel very responsible), but then he'd seemed to be less active and less alert and I wasn't sure if he was well for some time before that.

Before it happened, the last few days I'd started to think he seemed a bit out of it, glazed over at times, not eating as much pellets, at one point he climbed onto my shoulder but felt sort of odd, limp almost. This evening right before it happened, he was playing, I'd just fed him, he'd watched the girls be fed and noticed they'd got a toy (was I think anticipating/wanting), I let him sniff my hand which I think smelt of them since he seemed interested, given him an apple stick, seemed very happy with that. I walked back in after being in the kitchen or about ten minutes and he was lying flatter than usual in his box. I could've thought he was resting after playing (which he's started to be sooner to do but not sure if he is quite right when doing so), but he just didn't look right. He seemed to snap back to normal as I talked to him, but, I don't know, it wasn't like going from resting to active, it was like a light being switched back on, and although he was bouncing round he was moving between things like his dust and bowl quickly almost like he didn't know what he was doing. Then he very suddenly curled onto his side. I sort of wondered if he'd got overly stressed/excited by all the stimulus (food, awareness of the girls, scent, toy) and if that was a trigger. It was horrible to watch and I honestly thought he was going to die suddenly (please can anyone tell me if that's likely? He'd looked fine earlier in the evening so it was such a shock).

I don't know if it was a seizure but would guess it was neurological? I had a rabbit once who caught I think a protozoa infection, it sort of reminded me of that in the way he circled (rabbit recovered initially and lived for some time longer seeming Ok but seemed to die from it eventually).

He's just come down and eaten some hay and looks a bit better right now, but I'm not sure if he'll go back into that sort of state again. I can take him to the vet tomorrow but the one who sees most chins isn't on and I'm not really sure what they should look for or what treatment there might be (that's safe for chins) if any.