Question about my cat Chevy

Question
Please help. My cat is having what looks like muscle spasms on his back. They are so bad, he doesn't know what is happening and starts running around the house, and also tries to lick the spot. We can see his whole back moving, and we are worried. What do you think this is?

Answer
Your cat is most likely having what is called 'neuritis,' which is a nerve pain that comes from around the root of the tail. It usually radiates up and causes the cat to twitch it's back and vigorously lick the area trying to relieve the pain.
Unfortunately, the only thing you can do is take him into the vets and have them give him a steroid injection for the inflammation.
Some vets put them on prednisone for a few days too or instead of the injection.
We have used both on cats and they work equally as well. The injection works faster however.
Some vets have never seen this condition so hopefully your's is a vet with some experience and can figure this out.
It is not as uncommon as you think. We have seen cats with it for decades. I have no idea what causes it, I don't think any one knows for sure.
One thing for sure is, the cat does act crazy while it is feeling this pain!
He will be ok until you get him in.One thing is, do NOT give him any kind of painkillers from home. They are all toxic to cats!!
Let me know what you do and what the vet does.