A 42-year-old woman presents to the ED with a sudden severe headache she describes as the worst of her life, with onset during exercise. No fever, no neck stiffness initially. How do we apply the SNOOP4 mnemonic to headache red flags? When is CT head non-contrast sufficient vs LP needed to rule out SAH? What are the other dangerous headache etiologies that must not be missed?
Be specific. Cite references where possible. Your credentials will be shown with your answer.