Actually it was seizure like activity that made them come to the conclusion that my husband was DID. They called them pseudo seizures.

Then last semester in my psych class, my professor was telling us about this little girl who she was almost certain that she had DID but didn't know for sure at the time, but she had these crazy seizures that were eventually linked to her switching between alters.

So no it is not uncommon at all. I am sorry you are dealing with this.