This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
Hypotension in acute spinal injury is due to: 
Select and explain. 
A. Loss of sympathetic tone, B. Loss of parasympathetic tone, C. Orthostatic hypotension, D. Vasovagal attack
A: Loss of sympathetic tone
Answer: A: Loss of sympathetic tone 
Explanation: • High spinal cord injuries can also result in systemic hypotension because of loss of sympathetic tone.
• The patient will usually have hypotension and relative bradycardia and will show evidence of good peripheral perfusion on physical examination.
• The term neurogenic shock is used but is somewhat of a misnomer because these patients are typically hyperdynamic, with high cardiac output secondary to loss of sympathetic vascular tone.
Treatment
• Hypotension associated with high spinal injury can be treated by alpha-agonist phenylephrine.