My brother was in a car accident but did not suffer any injuries to the head or brain. He was awake and gave the ER my mom s number before they took him into surgery for his ankle. It s now been 10 days and he still hasn t woken up. They did 3 EEG s which showed normal brain activity and 2 CT scans which were normal. He opens his eyes but has a blank stare and he moves his mouth, hands, and leg. Does anyone know what could be the reason he s not waking up.

Summarized question: What leads to unresponsiveness while having normal vital signs?