BristolGals, it seems the "visitors" are not benign. Is your mum normally lucid?
Perhaps you can persuade to analyse things and ask herself: Does this situation make sense? Is this real?
But I suppose that if she is not lucid during such episodes, then that won't work.
Does she have any favourite movies that might calm her? Or a favourite piece of music?
Presumably, either the medication is causing this, or she has some condition in addition to PD?
Do you mind saying what medication she is on?
My friend is on Ropinirole, and it made her olfactory sense go a little crazy.
It also made her somewhat paranoid. Then she was put on Clopidogrel, a blood-thinner.
This aggravated the paranoia to such an extent that she often views me as the enemy.
Are you ever able to convince her that the "visitors" aren't there?
Maybe a change of medication?
Maybe give her some PEMF (Pulsed ElectroMagnetic Fields) treatment?
I'm really sorry to hear of such suffering, and I wish I could do more to help.
Best of luck, BristolGals.