What Causes Episodes Of Hallucinations Along With Migraines?

I am helping care for a woman who had normal migraines until the change. After that, she started having complex migraines. Usually her confusion only lasted about a week, but she in now on her fifth week and is completely confused and seeing people -- even talking to them -- who are not there. She thinks she is at someone else s home that looks just like hers, and no matter how many times we tell her she is home, within a couple of minutes, she is back to thinking the same thing. She has had Cat scans, MRS s, etc. that show nothing. What is going on and what can we do for her?