Headache

Key considerations: Subarachnoid hemorrhage (SAH), Meningitis / Encephalitis, Intracranial mass / tumor

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history: Onset: sudden (thunderclap → SAH) vs gradual; Quality, severity, location, duration; Associated: nausea, vomiting, photophobia, phonophobia, aura (migraine); Fever, neck stiffness, rash (meningitis); Visual changes, jaw claudication (GCA in elderly); Prior headache history — is this different from usual?; Medications: anticoagulants, OCP (CVST risk), analgesic overuse; exam: Fundoscopic: papilledema (IIH, mass), subhyaloid hemorrhage (SAH); Neck: meningismus (meningitis, SAH); Neurological: focal deficits, cranial nerve palsies; Temporal artery: tenderness, decreased pulsation (GCA); Mental status: confusion, altered consciousness; labs: CBC, BMP, ESR/CRP (GCA: ESR >50 highly suspicious); Blood cultures if meningitis suspected; Coagulation studies if on anticoagulants; COHgb if CO poisoning suspected; Lumbar puncture: opening pressure (IIH), xanthochromia (SAH), cell count/culture (meningitis); imaging: CT head non-contrast: first-line for thunderclap headache, SAH (95% sensitive within 6 hours); CT angiography: aneurysm, CVST, dissection; MRI/MRV: CVST, mass, IIH, posterior fossa lesions; CTA or MRA if SAH suspected but CT negative; bedside: Point-of-care optic nerve sheath diameter (>5mm suggests elevated ICP); Visual acuity if visual symptoms

immediate: Assess for life-threatening causes first — thunderclap headache = SAH until proven otherwise; IV access if concerning features present; Empiric antibiotics + dexamethasone if meningitis suspected — do not delay for LP or imaging; general: Migraine: metoclopramide 10mg IV + diphenhydramine 25mg IV + ketorolac 30mg IV (ED migraine cocktail); IV fluids for dehydration-associated headache; Dark, quiet room for migraine; specific: diagnosis: Subarachnoid Hemorrhage; steps: CT head → if negative and <6 hrs, may not need LP (with CTA); CT head → if negative and >6 hrs, LP for xanthochromia; If SAH confirmed: neurosurgery consult immediately; BP control: nicardipine drip, target SBP <160; Nimodipine 60mg PO q4h for vasospasm prevention; diagnosis: Meningitis; steps: Empiric antibiotics IMMEDIATELY: ceftriaxone 2g IV + vancomycin 25mg/kg IV; Dexamethasone 0.15mg/kg IV before or with first antibiotic dose; LP when safe — do not delay antibiotics for LP; Add ampicillin if >50 years, immunocompromised, or alcoholic (Listeria coverage); diagnosis: Temporal Arteritis; steps: ESR + CRP — if elevated, start prednisone 60-80mg PO immediately; Temporal artery biopsy within 2 weeks (steroids do not affect biopsy for ~2 weeks); Do not wait for biopsy to start steroids — risk of permanent vision loss

admit: SAH confirmed; Meningitis (ICU if severe); New intracranial mass; Cerebral venous sinus thrombosis; Persistent severe headache not responding to treatment; discharge: Migraine responding to treatment with return to baseline; Tension headache with normal exam; Negative SAH workup (CT + LP or CT + CTA within 6 hours); Follow-up with PCP or neurology for new or changing headache pattern; consults: Neurosurgery: SAH, intracranial mass, hydrocephalus; Neurology: first severe migraine, refractory headache, CVST; Ophthalmology: GCA with visual symptoms — emergent

Thunderclap headache (maximal intensity at onset) = SAH until proven otherwise — sensitivity of CT within 6 hours is 98.7%
In meningitis: antibiotics first, imaging/LP second — every minute of delay in antibiotics increases mortality
GCA: ESR >50 + new headache in patient >50 = start steroids immediately — do not wait for biopsy. Vision loss is irreversible
Carbon monoxide poisoning headache: multiple household members with headache is classic — check COHgb
The ED migraine cocktail (metoclopramide + diphenhydramine + ketorolac) is more effective than opioids for migraine

AAN/AHS Headache Guidelines, IDSA Meningitis Guidelines 2017, ACR GCA Guidelines 2021. Last reviewed: 2024-11-01