A 30-year-old man is brought to the emergency department following a high-speed car accident. He was the driver, and the windshield of the car was broken. On examination, he is alert, awake, oriented, and in no respiratory distress. He is unable to move any of his four extremities; however, his extremities are warm and pink. His vital signs on admission are HR 54 bpm and BP 70/40 mm Hg. What is the diagnosis?