A. There are a number of possibilities that could cause your cat's symptoms; ingestion or exposure to toxin, neurological disease, seizure activity, just to name a few. The ear scratching may or may not be related, it's possible that an ear infection is bothering him enough the make him painful and shaky. I recommend getting him seen by a vet as soon as possible for an exam and labwork, possibly x-rays, so your cat's condition can be diagnosed and he can be started on treatment as soon as possible so he can get some relief.
Your account has been reactivated.