Headache in the Emergency Department: 13 Dangerous Causes

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Also: RCVS and PRES, especially pregnant/postpartum (who are also at particular risk for CVST and of course preeclampsia).

emergency clinicians do not rule in migraine or other benign causes of headache. unless the headache is congruent to an established pattern for that patient, the history and physical specifically targets these 13 conditions.

subarachnoid hemorrhage: family history, PCKD, known berry aneurysm, sudden and maximal intensity at onset, posterior location

intracerebral hemorrhage: trauma, coagulopathy, decreased level of consciousness, hypertension

CNS infection: fever, immunocompromise, CNS instrumentation, recent head/face infection, meningismus

increased intracranial pressure: slowly progressive, cancer history, worse in morning, worse with head in dependent position, papilledema

carbon monoxide toxicity: contacts with similar illness, locationality (worse at home or at work)

acute angle closure glaucoma: unilateral anterior location, precipitated by darkness, change in vision, red eye

temporal (giant cell) arteritis: elderly, temporal location, jaw claudication, shoulder girdle symptoms

cervical artery dissection: unilateral pain involving neck/face, trauma history

cerebral venous sinus thrombosis: thrombophilia, neurologic signs/symptoms in non-arterial distribution, eyelid edema, proptosis

hypertensive encephalopathy: altered mentation, marked hypertension, improves with antihypertensive therapy

ENT/dental infection: ear, sinus, dental findings

idiopathic intracranial hypertension: young overweight female, hormone use, vision changes

preeclampsia: late pregnancy or postpartum


Ottawa SAH Rule / ACEP Headache Clinical Policy, June 2019

1. Neck pain/stiffness

2. Age ≥40

3. Witnessed LOC

4. Onset during exertion

5. Thunderclap (peak intensity at onset)

6. Limited neck flexion on exam

If one or more features present, CT. If negative CT within 6 hours of onset and neuro exam normal, SAH ruled out. Otherwise CT angio or LP may be used as second test.