What Causes Visual Hallucination And Severe Agitation?

Hi My mother 82 years old, she was fine before 8 month ago, then she became agitated and aggressive and saw a visual hallucination ,, Sometimes she become semi-normal and then return to the same condition, She remembers her name, her family name and our names, but she does not like to talk, Do drugs that she take have a relationship or side effects may be the cause? I want send you her midical report but i do not know how to .