My Mom will look like she is sleeping. The nursing home used to call her "unresponsive" and send her to the hospital. They would do a bunch of tests, stop and change meds, keep her there for up to ten days and in the end she would go back on the same meds. After a few episodes of this we discovered she was really not "unresponsive". if you annoyed her she would grimace or push you away! But she would not move otherwise. She would not take her meds, go to a more comfortable chair or bed,... but if we left her alone, after a while she will "wake up" and act like nothing happened. We now say she is "playing opossum" and leave her be. It sure beats long hospital stays. I think accepting many of the idiosyncracies of this disease is important to surviving as a caregiver and a patient. So my theory is that sleeping may not always be sleeping!