01Approach to the Critical Patient/attcp61

Immediate stabilization

›Airway and mental status threats

›GCS < 13 or rapidly declining consciousness

›Immediate CT head without contrast

›Prepare for definitive airway if unable to protect

›Thunderclap onset headache with altered sensorium

›Activate stroke or neurosurgical team

›IV access, continuous cardiac monitoring

›Signs of herniation

›Unequal pupils or fixed dilated pupil

›Posturing or Cushing response

›Hemodynamic and vital sign threats

›Severe hypertension (SBP > 180 mmHg) with headache

›Hypertensive emergency consideration

›Posterior reversible encephalopathy syndrome (PRES) risk

›Fever above 38.5 C with meningismus

›Immediate blood cultures and LP consideration

›Empiric antibiotics within 30 minutes if bacterial meningitis suspected

›Hypotension with headache

›SAH with cardiac stunning or volume depletion

›Septic shock from CNS infection

Key decision points

›Thunderclap headache triage

›Peak intensity within 60 seconds

›SAH until proven otherwise

›CT head without contrast as first test

›CT head sensitivity for SAH

›98.7% sensitivity within 6 hours of onset

02History/hx124

Headache characterization

›Onset and timing

›Thunderclap onset (peak within seconds to 1 minute)

›Highest risk for SAH

›>40% pretest probability for serious pathology

›Gradual onset over hours to days

›Subacute mass lesion or CVT pattern

›Tension-type or migraine

›Time of day

›Morning headache with raised ICP

›Nocturnal cluster attacks

›Location and character

›Unilateral location

›Migraine predominant

›Cluster (orbital or temporal)

›Bilateral location

›Tension-type headache predominant

›Raised ICP pattern

›Occipital or posterior

›SAH radiation to neck

›Posterior fossa lesion

›Pressing or tightening quality

›Tension-type headache

›Pulsating or throbbing quality

›Migraine

›Boring or stabbing quality

›Cluster headache

›Severity

›Mild to moderate severity

›Tension-type headache typical

›Moderate to severe severity

›Migraine typical

›Worst headache of life

›SAH red flag

›RCVS thunderclap variant

Associated symptoms and red flags

›Neurologic symptoms

›Visual aura

›Migraine with aura

›Homonymous field cut suggests posterior lesion

›Focal weakness or sensory loss

›Stroke or mass lesion

›Hemiplegic migraine rare variant

›Altered level of consciousness

›SAH, meningitis, encephalitis

›Intracranial mass with herniation

›Seizure activity

›CVT, abscess, or mass lesion

›Ophthalmologic symptoms

›Eye pain with injection and halos

›Acute angle-closure glaucoma

›Requires urgent IOP measurement

›Ipsilateral ptosis and miosis

›Cluster headache autonomic features

›Horner syndrome if posterior circulation aneurysm

›Diplopia

›Third nerve palsy (posterior communicating aneurysm)

›Raised ICP with sixth nerve palsy

›Transient visual obscurations

›Idiopathic intracranial hypertension

›Systemic symptoms

›Fever and neck stiffness

›Bacterial meningitis classic triad

›Triad present in only 40-50% of confirmed cases

›Jaw claudication and scalp tenderness

›Giant cell arteritis (age >50)

›ESR and CRP elevation expected

›Weight loss and night sweats

›Malignancy or CNS lymphoma

›Opportunistic infection in immunocompromised

Headache pattern and history

›Duration per episode

›30 minutes to 7 days

›Tension-type headache

›4 to 72 hours

›Migraine

›15 minutes to 3 hours

›Cluster headache

›Aggravating and alleviating factors

›Worsened by routine physical activity

›Migraine diagnostic criterion

›Positional component

›Orthostatic (worse upright) suggests CSF leak

›Worse supine suggests raised ICP

›Triggered by cough, Valsalva, or exertion

›Posterior fossa lesion or Chiari malformation

›SAH consideration

›Relief with dark and quiet environment

›Migraine photophobia and phonophobia

›Prior headache history

›Established primary headache diagnosis

›Identical to prior attacks (reassuring for primary)

›Pattern change is a red flag

›Previous similar headache with prior negative workup

›Associated with lower risk (OR 0.4 for SAH)

›New headache type in patient >50

›Requires imaging to exclude secondary cause

Risk factors and context

›Migraine risk factors

›Female sex

›3:1 female predominance

›Age 20 to 50 years

›Family history of migraine

›Obesity, depression, anxiety, and sleep disorders

›Vascular risk factors

›SAH risk

›Hypertension, smoking, heavy alcohol use

›Family history of aneurysm or SAH

›Polycystic kidney disease and connective tissue disorders

›CVT risk

›Oral contraceptives (8-fold increased odds)

›Pregnancy and puerperium

›Thrombophilia (factor V Leiden, protein C/S deficiency)

›Malignancy, autoimmune disease, dehydration

›Infection risk

›Immunosuppression (HIV, transplant, steroids)

›Opportunistic CNS infection

›Cryptococcal meningitis consideration

›Recent travel or sick contacts

›Bacterial or viral meningitis

›Medication history

›Acute analgesic frequency

›Analgesics ≥15 days per month suggests MOH

›Triptans, ergots, opioids ≥10 days per month suggests MOH

›Anticoagulant use

›Intracranial hemorrhage risk

›Nitrates, PDE5 inhibitors, oral contraceptives

›Medication-induced headache consideration

03Physical Exam/exam78

Vital signs and general assessment

›Vital sign interpretation

›Temperature

›Fever with headache and meningismus (meningitis/encephalitis)

›Temperature above 38.5 C as infection threshold

›Blood pressure

›SBP >180 mmHg (hypertensive emergency, PRES)

›Widened pulse pressure (Cushing response with herniation)

›Heart rate

›Bradycardia with hypertension (Cushing triad)

›Respiratory rate

›Irregular breathing pattern (herniation)

›General appearance

›Level of consciousness

›GCS scoring

›Confusion or agitation

›Photophobia and phonophobia

›Migraine or meningitis

›Degree of sensitivity

Neurologic examination

›Mental status

›Orientation and attention

›Encephalopathy versus focal deficit

›Language assessment

›Aphasia suggesting dominant hemisphere lesion

›Cranial nerve examination

›Pupillary size and reactivity

›Unilateral fixed dilated pupil (posterior communicating aneurysm, herniation)

04Differential Diagnosis/ddx89

Life-threatening secondary causes

›Subarachnoid hemorrhage (SAH)

›ICD-10 I60.9

›Thunderclap onset

›Approximately 5% of acute-onset ED headaches

›Aneurysmal SAH in 85% of spontaneous cases

›Posterior communicating artery most common site

›Third nerve palsy as sentinel sign

›Bacterial meningitis and encephalitis

›ICD-10 G00.9 bacterial meningitis

›Classic triad (headache, fever, neck stiffness) in 40-50%

›Altered mental status in 78% at presentation

›Viral encephalitis

›HSV encephalitis most common treatable cause

›Behavioural change and fever with headache

›Intracranial mass

›ICD-10 C71.9 malignant neoplasm of brain

›Progressive subacute headache

›Focal neurologic deficits and papilledema

›Brain abscess

›Fever, headache, focal deficit triad

›Ring-enhancing lesion on CT with contrast

›Cerebral venous sinus thrombosis (CVT)

›ICD-10 G08

›Subacute progressive headache in 90%

›Young women on oral contraceptives most common

›May present with seizures, focal deficits, or papilledema

›Diagnosis requires MRI/MRV or CT venography

›Intracranial hemorrhage

›ICD-10 I61.9 intracerebral hemorrhage

›Focal neurologic deficits with sudden headache

›Hypertension most common etiology

Vascular and hypertensive causes

›Hypertensive emergency

›ICD-10 I10 with target organ damage

›SBP >180 mmHg with end-organ dysfunction

›PRES pattern on MRI

›Differentiated from hypertensive urgency by end-organ damage

›Giant cell arteritis (GCA)

›ICD-10 M31.6

›Age >50 years mandatory criterion

›Visual loss in up to 20% if untreated

›ESR >50 mm/hr in 90%, CRP elevated

›Temporal artery biopsy for confirmation

›RCVS (reversible cerebral vasoconstriction syndrome)

›Recurrent thunderclap headaches

›Multiple episodes over days to weeks

›Triggered by sexual activity, exertion, or emotion

›Diagnosis by CTA or MRA showing segmental vasospasm

Primary headache disorders

›Tension-type headache

›ICD-10 G44.2

›Most common headache overall

›Bilateral, pressing, mild to moderate severity

›Not worsened by routine activity

›No nausea, photophobia, or phonophobia (or only one)

›Migraine

›ICD-10 G43.909

›Most common disabling headache presenting to care

›Unilateral, pulsating, moderate to severe

›ICHD-3 criteria: 2 of 4 (unilateral, pulsating, moderate-severe, worse with activity) plus nausea or photo/phonophobia

›Cluster headache

›ICD-10 G44.009

›Male predominance 3:1

›Strictly unilateral orbital or temporal, excruciating

›Ipsilateral autonomic features required

›Lacrimation, rhinorrhea, ptosis, conjunctival injection

›Medication overuse headache (MOH)

›ICD-10 G44.40

›≥15 headache days per month for >3 months

›With regular overuse of acute headache medications

›Opioids and barbiturates carry highest MOH risk

›Triptans carry relatively lower risk

Other secondary causes

›Acute angle-closure glaucoma

›ICD-10 H40.219

›Eye pain, conjunctival injection, halos, blurred vision

›Mid-dilated fixed pupil

›IOP elevation above 21 mmHg

›Ophthalmology emergency

›Idiopathic intracranial hypertension (IIH)

›ICD-10 G93.2

›Young obese women most commonly

›Papilledema, pulsatile tinnitus, transient visual obscurations

›CSF opening pressure above 25 cmH2O

›Cervicogenic headache

›ICD-10 M54.2

›Neck pain with limited cervical ROM

›Headache reproduced by cervical provocation

›Carbon monoxide poisoning

›ICD-10 T58.91XA

›Multiple affected individuals in same environment

›Carboxyhemoglobin elevation on co-oximetry

05Laboratory Tests/lt62

Core investigations for secondary cause

›Complete blood count

›Leukocytosis in meningitis, encephalitis, abscess

›Sensitivity limited; normal CBC does not exclude infection

›Thrombocytopenia in CVT-associated conditions

›Anemia contributing to headache in severe cases

›Comprehensive metabolic panel

›Electrolyte derangements causing headache

›Hyponatremia (osmotic change)

›Hypercalcemia

›Renal function for antibiotic and medication dosing

›Glucose

›Hypoglycemia as headache mimic

›Inflammatory markers

›ESR

›Above 50 mm/hr in 90% of GCA cases

›Above 100 mm/hr strongly associated with GCA

›CRP

›Elevated in GCA, meningitis, and secondary headaches

›More sensitive than ESR in some GCA cases

›Coagulation studies

›PT/INR and aPTT in anticoagulated patients

›Intracranial hemorrhage risk assessment

›D-dimer

›CVT screening (sensitive but not specific)

›Normal D-dimer does not exclude CVT

Specific diagnostic labs

›Blood cultures

06Diagnostic Tests/dt136

Scoring Systems

›Ottawa Subarachnoid Hemorrhage Rule

›Applies to alert patients ≥15 years with non-traumatic acute severe headache

›Age ≥40 years

›Neck pain or stiffness

›Witnessed loss of consciousness

›Onset with exertion

›Thunderclap headache

›Limited neck flexion on exam

›Any single criterion positive

›Sensitivity 100%, specificity 13.6% for SAH

›ACEP Level B recommendation to guide CT decision

›SNNOOP10 Mnemonic (secondary headache red flags)

›Systemic illness, Neoplasm history, Neurologic deficit

›New onset headache after age 50

›Onset thunderclap

›Onset with exertion, Valsalva, or positional change

›Papilledema, Prior headache type change

›Postpartum period

›Progressive headache pattern

›Presence of any flag mandates secondary workup

›Imaging minimum requirement

›ICHD-3 Migraine Diagnostic Criteria

›At least 5 attacks meeting criteria

›Duration 4-72 hours

›At least 2 of: unilateral, pulsating, moderate-severe, worse with activity

›At least 1 of: nausea/vomiting, photophobia and phonophobia

›Not attributed to another disorder

›Hunt and Hess Scale (SAH severity grading)

›Grade I: Asymptomatic or mild headache

›Mortality approximately 1%

›Grade II: Moderate-severe headache, no neurologic deficit except CN palsy

›Mortality approximately 5%

›Grade III: Drowsiness, confusion, or mild focal deficit

›Mortality approximately 19%

›Grade IV: Stupor, moderate-severe hemiparesis

›Mortality approximately 42%

›Grade V: Coma, decerebrate posturing

›Mortality approximately 77%

MRI

›MRI head without contrast (first-line for suspected CVT, posterior fossa, IIH)

›Indications

›Subacute progressive headache with negative CT

›Suspected CVT (requires MRV addition)

›Posterior fossa pathology concern

›IIH evaluation

›Sequence selection

›FLAIR for subarachnoid blood (sensitive after 4 hours)

›DWI for acute ischemic stroke

›T2 for demyelination and structural lesions

›T1 post-gadolinium for leptomeningeal enhancement

›Sensitivity and limitations

›Superior to CT for posterior fossa lesions

›Less available in acute ED setting

›FLAIR sensitivity for SAH 94% vs CT 98.7% within 6 hours

›MRI with gadolinium contrast

›Leptomeningeal carcinomatosis

›Enhancement pattern along sulci

›Brain abscess

›Ring-enhancing lesion with DWI restriction

›CNS infection

›Meningeal enhancement pattern

›MRA (MR angiography)

›Intracranial aneurysm detection

›Sensitivity 86-99% for aneurysms ≥3 mm

›Lower sensitivity for aneurysms <3 mm

›RCVS diagnosis

›Segmental vasoconstriction pattern

›May be normal early in RCVS course

›MRV (MR venography)

›CVT diagnosis

›Sensitivity 90-95% for sinus thrombosis

›Absent flow in affected sinus

›AHA/ASA 2024 Class I recommendation for CVT diagnosis

CT

›CT head without contrast (first-line acute headache with red flags)

›Indications

›Thunderclap headache

›Altered mental status

›Focal neurologic deficits

›Papilledema or signs of raised ICP

›New headache in immunocompromised patient

›SAH detection

›Sensitivity 98.7% within 6 hours of onset

›Sensitivity decreases to 85-90% after 24 hours

›Blood appears hyperdense in subarachnoid space

›Other findings

›Intracranial hemorrhage

›Hydrocephalus

›Mass lesion

›Midline shift

›CT angiography (CTA) head

›Indications

›Positive CT for SAH (aneurysm localization)

›Negative CT but high clinical suspicion (alternative to LP)

›Suspected RCVS or vasculitis

›Aneurysm detection

›Sensitivity 96-98% for aneurysms >3 mm

›ACEP Level B recommendation as alternative to DSA for SAH diagnosis

›Radiation and contrast considerations

›Contrast nephropathy risk in renal impairment

›Iodinated contrast allergy premedication protocol

›CT venography (CTV)

›CVT when MRV unavailable

›Sensitivity 75-100% for major sinus thrombosis

›Hyperdense sinus sign on non-contrast CT

›Combined CTA/CTV

›Single contrast bolus for both arterial and venous assessment

›CT head with contrast

›Brain abscess or neoplasm

›Ring-enhancing lesion detection

›Leptomeningeal enhancement

Ultrasound

›Point-of-care ultrasound (POCUS) optic nerve sheath diameter

›Measurement technique

›Linear probe (7.5-10 MHz) over closed upper eyelid

›Measure 3 mm posterior to globe

›Normal <5.0 mm

›Raised ICP detection

›Diameter >5.0-5.7 mm suggests ICP >20 mmHg

›Sensitivity 74-90%, specificity 85-95%

›Clinical utility

›Rapid bedside screen when LP or CT delayed

›Not a replacement for definitive imaging

›ACEP Level C evidence for ICP estimation

›Transcranial Doppler (TCD)

›Vasospasm detection post-SAH

›Mean velocity >120 cm/sec suggests vasospasm

›Lindegaard ratio >3 distinguishes cerebral from systemic hyperemia

›Not routinely performed in ED

›Carotid and vertebral duplex ultrasound

›Cervical artery dissection

›Limited sensitivity compared to CTA or MRA

›May show reduced flow or intimal flap

›Indicated when CTA/MRA unavailable and dissection suspected

›Temporal artery ultrasound

›GCA diagnosis

›Hypoechoic halo sign around temporal artery

›Sensitivity 69%, specificity 82% for GCA

›Reduces need for biopsy in high-probability cases

07Disposition/dispo44

Admission criteria

›Immediate ICU or neurosurgical admission

›Confirmed SAH

›Neurosurgical consultation for aneurysm coiling or clipping

›Nimodipine 60 mg every 4 hours for vasospasm prophylaxis

›Bacterial meningitis or encephalitis

›Empiric antibiotics initiated

›Neurologic monitoring required

›Intracranial hemorrhage with mass effect

›Herniation monitoring

›Neurosurgical evaluation for evacuation

›Altered mental status with undetermined etiology

›General ward admission

›Status migrainosus

›Refractory to ED parenteral treatment

›IV hydration and repeat antiemetic dosing

›CVT diagnosis requiring anticoagulation monitoring

›IIH with visual threat requiring ophthalmologic monitoring

›Intractable vomiting preventing oral intake

›New focal neurologic deficit requiring serial assessment

Observation indications

›Diagnostic uncertainty requiring further workup

›Awaiting LP results after negative CT

›Xanthochromia interpretation

›Awaiting MRI or MRV availability

›Subacute CVT or posterior fossa concern

›Partial treatment response requiring repeat dosing

›Migraine responding partially to first antiemetic dose

08Treatment/t148

Migraine (ED parenteral therapy)

›First-line antiemetics

›Prochlorperazine

›10 mg IV over 15 minutes

›Pre-treat with diphenhydramine 25 mg IV to prevent akathisia

›Level A evidence (must offer) per AHS 2025 guideline

›Repeat dose at 20-30 minutes if partial response

›Metoclopramide

›10 mg IV over 15 minutes

›Diphenhydramine pre-treatment also recommended

›Level B evidence per AHS 2025 guideline

›Alternative when prochlorperazine unavailable

›Second-line and adjunct therapies

›Ketorolac

›15-30 mg IV (30 mg IM)

›Useful adjunct to antiemetics

›Avoid in renal impairment and GI bleeding history

›Dexamethasone

›8-10 mg IV single dose

›Reduces migraine recurrence within 24-72 hours

›NNT approximately 9 for recurrence prevention

›Valproate sodium

›500-1000 mg IV over 30 minutes

›Consider when antiemetics fail

›Avoid in pregnancy (Category X)

›Diphenhydramine

›25-50 mg IV

›Adjunct for rescue and akathisia prevention

›Rescue therapy for refractory migraine

›Dihydroergotamine (DHE)

›1 mg IV or IM with antiemetic pre-treatment

›Highly effective for status migrainosus

›Contraindicated in CAD, stroke, basilar migraine, pregnancy

›Magnesium sulfate

›1-2 g IV over 15-60 minutes

›Particularly effective in migraine with aura

›May reduce frequency in menstrual migraine

›Opioids

›Must NOT be offered for migraine (Level A must-not-offer per AHS 2025)

›Increase risk of MOH and emergency department recidivism

›Hydromorphone IV specifically contraindicated

Tension-type headache treatment

›First-line therapy

›Acetaminophen

›1000 mg PO

›Maximum 4000 mg per 24 hours

›Ibuprofen

›400 mg PO

›Avoid in renal impairment, GI bleeding, and cardiac disease

›Naproxen sodium

›550 mg PO

›Alternative NSAID option

Cluster headache treatment

›Abortive therapy

›High-flow oxygen

›12-15 L/min via non-rebreather mask

›Continue for 15-20 minutes

›Response rate 78-98%

›First-line treatment per ICHD guidelines

›Sumatriptan

›6 mg subcutaneous injection

›Onset of relief within 15 minutes in 75% of patients

›Contraindicated in CAD, prior stroke, and uncontrolled hypertension

›Zolmitriptan

›5 mg nasal spray

›Alternative to sumatriptan injection

›Onset 15-30 minutes

Secondary headache treatment

›SAH management

›Blood pressure control

›Target SBP <160 mmHg before aneurysm secured

›Nicardipine 5 mg/hr IV titrated to target

›Labetalol 10-20 mg IV bolus as alternative

›Nimodipine

›60 mg PO every 4 hours for 21 days

›Reduces delayed cerebral ischemia from vasospasm

›AHA/ASA 2023 Class I recommendation

›Neurosurgical intervention

›Endovascular coiling preferred for most aneurysms

›Open surgical clipping for select morphologies

›Venous thromboprophylaxis after aneurysm secured

›Sequential compression devices until mobilized

›Bacterial meningitis treatment

›Empiric antibiotics

›Ceftriaxone 2 g IV every 12 hours

›Add ampicillin 2 g IV every 4 hours if Listeria risk (age >50, immunocompromised)

›Add vancomycin 25-30 mg/kg IV loading dose if MRSA risk or resistant pneumococcus concern

›Dexamethasone

›0.15 mg/kg IV every 6 hours for 4 days

›Start 15-20 minutes before or with first antibiotic dose

›Reduces hearing loss and neurologic sequelae in S. pneumoniae meningitis

›IV herpes coverage

›Acyclovir 10 mg/kg IV every 8 hours if HSV encephalitis cannot be excluded

›Dose adjusted for renal function

›CVT treatment

›Anticoagulation

›Low-molecular-weight heparin preferred initial therapy

›Enoxaparin 1 mg/kg subcutaneous every 12 hours

›Continue despite presence of hemorrhagic transformation

›AHA/ASA 2024 Class I recommendation

›Direct oral anticoagulants

›Dabigatran or rivaroxaban for long-term treatment

›Duration 3-12 months depending on risk factors

›GCA treatment

›Prednisone

›1 mg/kg PO per day (maximum 60 mg)

›Start immediately when GCA suspected

›Do not delay for temporal artery biopsy

›If visual symptoms present

›Methylprednisolone 1 g IV daily for 3 days

›Ophthalmology consultation same day

›IIH treatment

›Acetazolamide

›250-500 mg PO twice daily

›Reduces CSF production

›Avoid in sulfonamide allergy

›Weight loss

›5-10% body weight reduction associated with symptom improvement

›LP therapeutique

›Transient relief of ICP

›Opening pressure monitored

›Ophthalmology referral

›Visual field monitoring mandatory

Outpatient migraine prescriptions

›Acute outpatient medications

›NSAIDs

›Ibuprofen 400-600 mg PO as first-line

›Naproxen sodium 500-550 mg PO alternative

›Triptans

›Rizatriptan 10 mg PO (fastest oral onset)

›Sumatriptan 50-100 mg PO or 6 mg SC

›Contraindicated in CAD, stroke, PAD, uncontrolled hypertension

›CGRP receptor antagonists (gepants)

›Ubrogepant 50-100 mg PO

›Rimegepant 75 mg PO (also preventive approval)

›No cardiovascular contraindications like triptans

›Lasmiditan (5-HT1F agonist)

›50-200 mg PO

›No vasoconstriction; safe in cardiovascular disease

›Driving restriction for 8 hours after dose

›Preventive therapy indications

›Prescribe when 4 or more headache days per month

›Significant disability (MIDAS score elevated)

›Medication overuse pattern

›First-line preventive options

›Topiramate 25-100 mg PO nightly

›Amitriptyline 10-75 mg PO nightly

›Propranolol 40-80 mg PO twice daily

›Valproate 250-500 mg PO twice daily (avoid in pregnancy)

›CGRP monoclonal antibodies

›Erenumab, fremanezumab, or galcanezumab monthly SC

›Indicated for ≥4 migraine days per month

›Prescribed by neurology or headache specialist

09Special Populations/sp103

Pregnancy

›Risk profile and unique etiologies

›CVT risk highest in postpartum period

›11.6 per 100,000 deliveries overall

›Peaked incidence in first postpartum week

›Present with progressive headache, focal deficits, or seizures

›Preeclampsia-associated headache

›New or worsening headache after 20 weeks gestation

›Associated with hypertension (SBP ≥140 mmHg or DBP ≥90 mmHg)

›Proteinuria and organ dysfunction

›RCVS in postpartum period

›Recurrent thunderclap headaches

›Highest incidence at 1-2 weeks postpartum

›Eclampsia

›Seizure in context of preeclampsia

›Magnesium sulfate for prevention and treatment

›Safe diagnostic imaging

›CT head without contrast

›Fetal radiation dose <1 mGy (below threshold for concern)

›Justified when clinical indication strong

›MRI without gadolinium

›Preferred for subacute presentations

›Gadolinium avoided in first trimester

›LP

›Safe in pregnancy

›Positional changes may be required

›Safe and contraindicated treatments

›Safe acute analgesics

›Acetaminophen 1000 mg PO (preferred across all trimesters)

›Magnesium sulfate 4-6 g IV loading for eclampsia prophylaxis

›Prochlorperazine safe in pregnancy for nausea and headache

›Treatments to avoid in pregnancy

›Triptans (Category C; avoid in first trimester)

›NSAIDs after 20 weeks (premature ductus arteriosus closure risk)

›Valproate (Category X; major teratogen)

›Ergotamine and DHE (Category X)

›Migraine management in pregnancy

›Acetaminophen as mainstay

›IV fluids for dehydration-associated migraine

›Metoclopramide safe for nausea

Geriatric

›Unique risk considerations

›New headache after age 50 always requires secondary exclusion

›GCA most common new vascular headache in this group

›Brain metastases peak incidence over 60

›Higher prevalence of intracranial aneurysms

›Prevalence approximately 3% in general population

›SAH risk increases with age

›Subdural hematoma mimicking headache

›History of minor trauma often absent

›Anticoagulant or antiplatelet use increases risk

›Chronic subdural may present as progressive headache

›GCA vigilance

›All patients >50 with new headache

›ESR and CRP at minimum

›Temporal artery tenderness examination essential

›Pharmacologic adjustments

›NSAIDs

›Increased GI, renal, and cardiovascular risk

›Use lowest effective dose for shortest duration

›Proton pump inhibitor co-prescription if NSAIDs used

›Dopamine antagonists (prochlorperazine, metoclopramide)

›Increased risk of extrapyramidal side effects and akathisia

›Diphenhydramine pre-treatment especially important

›Monitor for tardive dyskinesia with repeated use

›Triptans

›Use with caution given higher cardiovascular risk

›Relative contraindication in uncontrolled hypertension

›Opioids

›Heightened delirium and fall risk

›Contraindicated for migraine regardless of age

›Acetaminophen dosing

›Maximum 2000 mg per 24 hours in hepatic impairment or malnutrition

Pediatrics

›Age-specific headache patterns

›Migraine in children

›Duration may be shorter (2-72 hours)

›Often bilateral in prepubertal children (unlike adults)

›Abdominal migraine variant (cyclic vomiting, abdominal pain)

›Prevalence 5-10% school-age, rising to 15-28% in adolescence

›Secondary causes of greater concern

›Posterior fossa tumors more common than in adults

›Medulloblastoma and ependymoma common pediatric brain tumors

›Intracranial hypertension from obstructive hydrocephalus

›Warning signs requiring urgent imaging

›Vomiting without nausea (posterior fossa sign)

›Worsening headache in morning with improvement during day

›Gait disturbance or behavioral change

›Age <5 years with new-onset headache

›Pediatric medication dosing

›Acetaminophen

›15 mg/kg PO or PR every 4-6 hours

›Maximum 75 mg/kg per day

›Ibuprofen

›10 mg/kg PO every 6-8 hours

›Maximum 40 mg/kg per day

›Prochlorperazine

›0.1-0.15 mg/kg IV (maximum 10 mg per dose)

›Age 2 years and over

›Ketorolac

›0.5 mg/kg IV (maximum 15-30 mg)

›Sumatriptan

›Approved for ages 12 and over in many jurisdictions

›10-20 mg nasal spray or 25-50 mg PO based on weight

›Magnesium sulfate

›25-50 mg/kg IV over 30-60 minutes (maximum 2 g)

10Background/b97

Epidemiology

›Prevalence and incidence

›Headache disorders affect approximately 90% of people during their lifetime

›Fourth leading cause of ED visits in the US

›Approximately 4.5% of all ED visits

›Primary headache types

›Tension-type headache: lifetime prevalence 30-78% globally

›Migraine: lifetime prevalence 14% globally

›Cluster headache: prevalence 0.1%, male predominance 3:1

›Secondary headache burden

›SAH approximately 5% of acute severe headache in ED

›Bacterial meningitis 2-5 per 100,000 per year

›CVT 3-4 per million per year (higher in younger women)

›Sex and age distribution

›Migraine: female-to-male ratio 3:1, peak ages 20-50

›Cluster: male predominance, peak onset age 20-40

›GCA: exclusively over age 50, female predominance 3:1

›Disability burden

›Migraine is the second leading cause of global disability

›Lost workdays and economic impact exceeds most chronic conditions

›High emergency department recidivism without proper outpatient management

Pathophysiology

›Primary headache mechanisms

›Migraine pathophysiology

›Cortical spreading depression (CSD) generates aura

›Slow wave of depolarisation spreading at 3-5 mm/min

›Triggers trigeminal activation via meningeal receptors

›Trigeminovascular activation

›CGRP release from trigeminal nerve terminals

›Neurogenic inflammation of dural blood vessels

›Central sensitization leads to allodynia

›Serotonin (5-HT1B/1D) receptor modulation as triptan mechanism

›Cranial vasoconstriction and CGRP release inhibition

›Tension-type headache pathophysiology

›Peripheral sensitization from pericranial muscle tenderness

›Central sensitization in chronic TTH

›Stress, sleep deprivation, and poor posture as modulators

›Cluster headache pathophysiology

›Hypothalamic activation (posterior hypothalamus)

›Trigeminoautonomic reflex drives ipsilateral autonomic features

›Circadian periodicity linked to suprachiasmatic nucleus

›Secondary headache mechanisms

›SAH pathophysiology

›Sudden ICP elevation causes acute pain at time of rupture

›Blood in subarachnoid space triggers meningeal irritation

›Vasospasm peaks at 4-10 days post-rupture

›Delayed cerebral ischemia affects 30% of survivors

›ICP elevation headache

›Dural stretching and traction on pain-sensitive structures

›Venous obstruction in CVT causes ICP rise

›CSF absorption failure in IIH

›Meningeal inflammation

›Cytokine release from infected or irritated meninges

›TNF-alpha, IL-1, and IL-6 activation of pain pathways

›Blood products in SAH act as chemical irritants

Therapeutic Considerations

›ED headache management principles

›Distinguish primary from secondary headache before treatment

›Red flags mandate imaging before symptomatic treatment

›Treatment of primary headache does not exclude secondary cause

›Avoid opioids in all ED headache presentations

›Level A must-not-offer per AHS 2025 for migraine

›Increases MOH risk and delays appropriate diagnosis

›Dopamine antagonists as backbone of ED migraine therapy

›Prochlorperazine Level A (must offer) per AHS 2025

›Address nausea, pain, and sensitization simultaneously

›MOH prevention and management

›MOH definition: acute medication use ≥10-15 days per month

›Analgesics and triptans ≥15 and ≥10 days respectively

›Opioids and barbiturates carry highest transformation risk

›Withdrawal approach

›Abrupt discontinuation of overused medication

›Bridge therapy with alternative class

›Prophylactic therapy initiation

›Education at ED discharge

›Maximum 2 days per week of acute analgesics

›Headache diary to track frequency and medication use

›CGRP pathway therapeutics

›Gepants (CGRP receptor antagonists)

›No vasoconstriction; triptan-free option

›Ubrogepant and rimegepant FDA-approved acute therapy

›Rimegepant also approved for preventive use

›CGRP monoclonal antibodies (preventive)

›Erenumab, fremanezumab, galcanezumab, eptinezumab

›Monthly or quarterly dosing

›Indicated when ≥4 migraine days per month

›Lasmiditan (5-HT1F agonist)

›Selective for 5-HT1F receptor without vasoconstriction

›Safe in cardiovascular disease

›CNS sedation and dizziness; 8-hour driving restriction

›Diagnostic approach limitations

›CT head overtesting is common

›Kaiser Permanente 2024 study: CT use increased 37% from 2015 to 2021 for ED headache

›Only 1.3% of ED headache CT scans identified serious findings

›LP underutilization post-negative CT

›Ottawa rule and clinical judgment guide LP decision

›Xanthochromia peaks at 12 hours and persists up to 2 weeks

›Clinical decision rules

›Ottawa SAH rule: 100% sensitivity for SAH in validated cohorts

›ACEP Level B: CTA as alternative to LP after negative CT in selected patients

11Patient Discharge Instructions/pdi29

copy discharge instructions

›Discharge instructions for Headache (Undifferentiated)

›Your diagnosis

›You were evaluated for your headache in the emergency department

›A serious cause of your headache was not identified today

›You have been diagnosed with a primary headache disorder (e.g., migraine or tension-type headache)

›Your medications

›Take prescribed medications as directed

›Avoid using pain medications more than 2 days per week to prevent rebound headache

›Do not take opioids for headache — they worsen the condition over time

›If prescribed a triptan, do not take within 24 hours of an ergotamine medication

›Care at home

›Rest in a quiet, dark room during a migraine attack

›Drink fluids to stay hydrated

›Apply ice pack to head or neck for comfort

›Keep a headache diary tracking frequency, duration, severity, and triggers

›Identify and avoid your personal triggers (alcohol, caffeine, poor sleep, stress, dehydration)

›Follow-up instructions

›See your family doctor within 1-2 weeks

›Ask about preventive headache medications if headaches occur 4 or more times per month

›You may need an outpatient MRI if imaging was not done today — your doctor will arrange this

›Return to the emergency department immediately if

›You develop the worst headache of your life or a sudden severe headache

›Your headache is associated with fever, neck stiffness, or a rash

›You develop new weakness, numbness, vision loss, difficulty speaking, or confusion

›You have a seizure

›Your headache is rapidly worsening or not improving with prescribed treatment

›You are vomiting and cannot keep fluids down

12References/r50

Guidelines and key sources

›Primary guideline references

›Robbins MS — Diagnosis and Management of Headache: A Review — JAMA 2021

›Comprehensive review of primary and secondary headache evaluation

›ICHD-3 criteria and clinical decision making framework

›Viera AJ, Antono B — Acute Headache in Adults: A Diagnostic Approach — AAFP 2022

›Ottawa SAH rule application and clinical decision algorithm

›Red flag identification and diagnostic pathway

›Do TP et al — SNNOOP10 List — Neurology 2019

›Red and orange flags for secondary headaches in clinical practice

›Evidence-based mnemonic for secondary headache screening

›Robblee J et al — 2025 AHS Guideline Update for Acute Migraine Treatment in the ED — Headache 2025

›Level A: prochlorperazine must offer; opioids must not offer

›Evidence assessment of parenteral pharmacotherapies

›VanderPluym JH et al — Acute Treatments for Episodic Migraine — JAMA 2021

›Systematic review and meta-analysis of acute migraine treatments

›Ashina M — Migraine — NEJM 2020

›Pathophysiology, CGRP pathway, and modern therapeutics

Vascular and secondary headache references

›SAH and aneurysm guidelines

›Hoh BL et al — 2023 AHA/ASA Guideline for Aneurysmal SAH — Stroke 2023

›Nimodipine Class I recommendation

›Endovascular versus surgical management criteria

›Claassen J, Park S — Spontaneous Subarachnoid Haemorrhage — Lancet 2022

›Vasospasm management and delayed cerebral ischemia prevention

›Lawton MT, Vates GE — Subarachnoid Hemorrhage — NEJM 2017

›Hunt and Hess grading and outcome prediction

›Walton M et al — Management of Sudden Onset Severe Headache in ED — EMJ 2022

Evidence & Review