My mother has had three surgeries - 1994, 2010, 2011 for meningioma - right temporal lobe. She also had radiation in 94 and 2011. She now has radiation necrosis for which she has gone through a round of steroids. Recently, she was admitted to the hospital due to extreme weakness and confusion. The EEG was abnormal but did not show seizures. She is on Levipil. She also suffered a heart attack while in the hospital. As of now, she is delirious and has slurred speech. What could be the cause of this?