Yes, that could be a shock or some kind of paralysis, or a cerebral disorder, and IMO this poor guy needs to go to the vet as soon as possible!

And did I get that right that your girls are in the same house now? Better make sure they don't have any contact with that kitty since you can't be sure about viral diseases (FIP for example can also cause cerebral disorders when the brain is affected!).

Poor kitty! Please keep us updated!

Kirsten