Daughter can't speak 10 days after first seizure

Sorry, this is going to be a long post, but we are at the end of our rope. My daughter is 4 years old. She is TPN dependent and has mild CP. The CP only causes left side muscle weakness. She is a very smart child and has been ahead of all of her mental milestones and only slightly behind her physical. She was in the hospital last week for a line infection (she has a central line) and had her first seizure after she was admitted. The seizure lasted about 10 minutes and she had to be given Adavan, Phenobarbatal, and Keppra to stop the seizure. They put her on Trileptal to control any future seizures. She was also put on a ventilator because of all the meds she was given. The doctors expected her to wake up within a few hours, but it took almost 30. When she woke up and they took her off of the vent, she was unable to open her eyes for the next several hours, but she stayed awake for about 24 hours. She was unable to speak or communicate at all. By the next night, we were able to tell that she was at least aware of her surroundings and could talk a bit. She started having hallucinations. The would see Minnie Mouse and try to catch her and giggle. She would also tell me she was afraid of the girl in hte corner. Every half hour or so she would scream in fear and sometimes didn't want me to be anywhere near her so the nurse would have to console her. The hallucinations stopped over the next couple of days, but she could barely sit up or stand. She slurred words and mumbled and appeared drunk. Over the past few days her balance and demeanor have gotten closer to normal. She laughs and plays. But she can't communicate. She can sing her ABC's and songs that she had memorized, but if you ask her simple questions she can't answer. Every now and then she'll say "Daddy I want a ..." and then she just stares blankly at you like she doesn't know the word. Occasionally, if you really make her concentrate, she can name her stuffed animals and things like that, but it's like pulling teeth. It is frustrating her and breaking our hearts. This was a kid who would say things to her nurse like "I have allergies to Vancomycin. Did you give me Benadryl?". Now she can't tell you what kind of pet she has at home or the name of her favorite place to shop. Has anyone been through something like this? IF she is improving, it is very very slowly. The doctors can't tell us if it is postical psychosis, side effects of the trileptal, or something else. Her EEG and CT were normal and we are doing a MRI on Monday. Sorry for rambling and thanks in advance for any help/advice.