Chin had a long seizure, took him to the vet, have an xray,need an opinion

A week after we got him he had a seizure for 3-4 minutes. We thought
he was done for, but he suddenly continued with
his usual business and was cheerful.

After a month he had a problem with his right eye. He would close it
sometimes and sometimes it would look fine.
Eye didn't look wet, but the hair around is was messed up. It seamed
to resolved itself after a week.

He poops and eats regularly even now. We have another chin that is
completely fine. Food wasn't changed and they get a raisin every 2-3
days.

-- 1 months later, last night

After his normal 10-15min time out of the cage (we let them out 4-5
times a day out of the cage), he just went into the cage and:

First had a spasm then, his whole body was shaking (small twitched)
for a second. every 3 seconds, every 1-2min several times that night.
He didn't have control over his legs, he was running and jumping badly
into things, but like he had brain damage.
He was tumbling all over, with his bum going to the side when he walked.

After few minutes of moving he would have a spasm and look like he is
going to die.
I massaged his belly and it seamed to help as he would go out of
spasm, and start running jumping again.
A few times he seamed completely fine, jumping well off the walls and such.

This was repeated for almost 2 hour until he lay in his cage shaking
uncontrollably.
Then the second chin lay next to him and he calmed down, so shaking stopped.

So he got through the night, and i went to the vet this morning. He
took an xray, which i attached.
He was much better this morning but not the same.
The vet said teeth are piercing (don't know a better word) through his
sinuses, and gave him this medicine: Cobactan 0.2ml and Cortisone
0.3ml
He said i should come tomorrow for a treatment but he doesn't know
what it will be.

He also said he will treat the sinuses/infection/teeth's situation but
doesn't know why he had that seizure.

---

So I'm posting here because frankly i trust you more then my vet, and
want an opinion about situation and xray.
I have x ray picture but I can't submit it, forum doesn't allow me.

I also have a few videos of him from last night if it helps ill upload them.

Thanks and sorry for my bad english.