I'm new to critical care and work in the cardiac ICU. My patient the other night was a vented elderly man showing minimal response. Pos gag/cough, neg babinksi, intermittent corneal's and response to pain; PERRLA; no response to voice. He recently started yawning occasionally, and when another nurse saw that she said, "well that's not good." I asked her what she meant, and she said that it was a "neuro yawn." She said she didn't know much, only that it meant that it was a bad sign, like it's another basic reflex that only shows up when a patient is or is nearly brain dead. Anyone able to explain this "neuro yawn" ?