A 24-year-old man found unconscious after head trauma has blood pressure of 190/110 mmHg, heart rate of 44 beats per minute, and irregular respirations. Pupils are equal and reactive. This combination most strongly suggests:

• A Spinal shock from cervical cord injury
• B Neurogenic shock from high thoracic injury
• C Acute intracranial hypertension with impending herniation ✓
• D Traumatic aortic injury with hypoperfusion

Explanation

The Cushing reflex is the brainstem response to critically raised ICP: sympathetic-mediated systemic hypertension to preserve cerebral perfusion, followed by baroreceptor-triggered bradycardia, plus irregular breathing from medullary compression. Spinal and neurogenic shock both cause hypotension with bradycardia, the opposite pattern. Aortic injury would present with pulse deficits and hypotension rather than this classic triad.

Reference: Guyton and Hall Textbook of Medical Physiology, 14th ed.

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Written and medically reviewed by the StethoPrep medical team.