What is the appropriate evaluation and workup for a patient presenting with headache, including red‑flag assessment, history, physical examination, investigations, and management?

Headache Workup: Evaluation and Management

Initial Assessment Framework

The cornerstone of headache evaluation is identifying red flags through focused history and neurological examination to distinguish life-threatening secondary causes from benign primary headache disorders. 1, 2

Critical Red Flags Requiring Immediate Action

• Thunderclap headache ("worst headache of life") suggests subarachnoid hemorrhage and requires non-contrast CT head within 6 hours (sensitivity 95% on day 0, declining to 74% by day 3) 1, 3
• Fever with neck stiffness indicates possible meningitis and mandates immediate evaluation 1, 2
• Papilledema on fundoscopy signals increased intracranial pressure 1, 4
• Focal neurological deficits (abnormal reflexes, gait disturbance, cranial nerve findings, altered sensation) 1, 5
• New-onset headache after age 50 raises concern for giant cell arteritis or mass lesion 1, 5
• Progressive worsening over weeks to months suggests space-occupying lesion 1, 5
• Headache worsened by Valsalva, cough, or exertion indicates possible increased intracranial pressure 1, 5
• Altered consciousness, memory, or personality changes 1, 2
• Headache awakening patient from sleep (less specific but concerning) 1, 5

Essential History Components

Document these specific features to differentiate primary from secondary headaches:

• Onset timing: Abrupt (seconds to minutes) vs. gradual (hours to days) 6, 2
• Duration of episodes: Migraine 4-72 hours; cluster 15-180 minutes; tension-type variable 1
• Frequency: Episodic vs. chronic (≥15 days/month for >3 months) 7, 1
• Pain location: Strictly unilateral (migraine, cluster) vs. bilateral (tension-type) 1
• Pain quality: Pulsating (migraine) vs. pressing/tightening (tension-type) vs. severe stabbing (cluster) 1
• Pain severity: Moderate-to-severe (migraine, cluster) vs. mild-to-moderate (tension-type) 1
• Aggravating factors: Routine activity worsens migraine but not tension-type 1
• Associated symptoms: Nausea/vomiting, photophobia, phonophobia (migraine); ipsilateral lacrimation, conjunctival injection, nasal congestion, ptosis (cluster) 1
• Aura symptoms: Visual/hemisensory disturbances lasting <60 minutes preceding headache 1
• Medication use: Document frequency of acute medication use (≥15 days/month non-opioid analgesics or ≥10 days/month other acute medications for >3 months suggests medication-overuse headache) 1

Common pitfall: Pediatric migraineurs have cranial autonomic symptoms (rhinorrhea, nasal congestion) in 62% of cases, frequently misdiagnosed as "sinus headache" 7, 4

Physical Examination Essentials

Perform a complete neurological examination including:

• Vital signs with blood pressure (hypertension may indicate increased intracranial pressure) 4
• Fundoscopic examination for papilledema (present in 60% of children with brain tumors) 7, 4
• Cranial nerve assessment (all 12 nerves) 4
• Motor and sensory testing 4
• Cerebellar function (finger-to-nose, heel-to-shin, rapid alternating movements) 4
• Gait evaluation (abnormalities suggest posterior fossa pathology) 4
• Mental status assessment 4
• Neck examination for stiffness or limited flexion (meningeal irritation) 1, 2
• Temporal artery palpation for tenderness in patients >50 years 1

Critical point: A normal neurological examination in primary headache has a <1% yield for clinically significant findings on neuroimaging 1, 4

Diagnostic Testing Algorithm

When Neuroimaging is NOT Indicated

Do not order neuroimaging for patients with:

• Normal neurological examination AND
• No red flags AND
• Headache pattern consistent with primary headache disorder (migraine, tension-type, cluster) 7, 1, 2

Evidence: In 449 children with headache, 21% had MRI abnormalities but <1% had relevant findings explaining the headache 7

When Neuroimaging IS Indicated

Emergent non-contrast CT head:

• Thunderclap headache presenting <6 hours from onset 1, 3
• Acute head trauma 5
• Any red flag with concern for hemorrhage or acute mass effect 3, 2

MRI brain (with and without contrast preferred):

• Any abnormal neurological finding 1, 4
• Progressive headache pattern over weeks to months 1, 5
• New-onset headache after age 50 1, 5
• Atypical aura (focal neurological symptoms or duration >60 minutes) 1
• Suspected tumor, inflammatory process, or posterior fossa pathology 7, 3
• Subacute presentations where CT is insufficient 1

Common pitfall: MRI is superior to CT for detecting tumors, stroke, and parenchymal abnormalities, but CT is faster and appropriate for acute hemorrhage evaluation 4, 3

Additional Investigations Based on Clinical Suspicion

Lumbar puncture (after neuroimaging if indicated):

• Normal CT but high suspicion for subarachnoid hemorrhage 3, 2
• Suspected meningitis or encephalitis 1, 2
• Suspected idiopathic intracranial hypertension (opening pressure measurement) 5, 3
• Suspected spontaneous intracranial hypotension (orthostatic headache pattern) 1

ESR/CRP:

• Suspected giant cell arteritis in patients >50 years with new-onset headache, scalp tenderness, or jaw claudication (note: ESR can be normal in 10-36% of cases) 1

TSH and free T4:

• Symptoms of hypothyroidism (cold intolerance, lightheadedness) 1

Screening questionnaires for primary headache:

• ID-Migraine (3-item): Sensitivity 0.81, specificity 0.75, positive predictive value 0.93 1
• Migraine Screen Questionnaire (5-item): Sensitivity 0.93, specificity 0.81, positive predictive value 0.83 1

Headache diary:

• Essential for chronic or recurrent headaches to document frequency, duration, triggers, associated symptoms, and medication use 1, 4

Diagnosis of Primary Headache Disorders

Migraine Without Aura

Diagnostic criteria require ALL of the following:

• ≥5 lifetime attacks lasting 4-72 hours (untreated or unsuccessfully treated) 1
• ≥2 pain characteristics: Unilateral location, pulsating quality, moderate-to-severe intensity, OR aggravation by routine physical activity 1
• ≥1 associated symptom: Nausea/vomiting OR both photophobia AND phonophobia 1

Key differentiator: The combination of photophobia with nausea strongly supports migraine over tension-type headache 1

Chronic Migraine

Diagnostic criteria:

• ≥15 headache days per month for >3 months 7, 1
• ≥8 days per month meeting migraine criteria 7, 1

Management implication: Chronic migraine requires prophylactic treatment initiation and has substantially greater disability than episodic migraine 7, 1

Tension-Type Headache

Clinical features:

• Bilateral location 1
• Pressing/tightening quality (non-pulsating) 1
• Mild-to-moderate intensity 1
• NOT aggravated by routine physical activity 1
• Lacks nausea/vomiting AND lacks the combination of photophobia plus phonophobia 1
• Duration: 30 minutes to 7 days 1

Chronic tension-type headache: ≥15 days per month for >3 months; first-line preventive therapy is amitriptyline 1

Cluster Headache

Diagnostic features:

• Strictly unilateral severe pain 1
• Duration 15-180 minutes 1
• Ipsilateral autonomic symptoms: Lacrimation, conjunctival injection, nasal congestion, rhinorrhea, ptosis, miosis 1
• Prevalence: 0.1% of population 1

Acute treatment: High-flow oxygen (100% at 12-15 L/min) first-line; subcutaneous or intranasal triptans alternative 1

Medication-Overuse Headache

Diagnostic criteria:

• ≥15 headache days per month 1
• Regular overuse of acute medications for >3 months: Non-opioid analgesics ≥15 days/month OR other acute medications ≥10 days/month 1

Management: Requires withdrawal of overused medication and preventive therapy 1

Management and Referral

Acute Treatment

Mild-to-moderate migraine:

• NSAIDs or acetaminophen first-line 1

Moderate-to-severe migraine or NSAID failure:

• Triptans or ergot derivatives 1
• Antiemetics for nausea/vomiting 1

Pediatric acute treatment:

• Ibuprofen 10 mg/kg every 6-8 hours (maximum 400 mg per dose) first-line 4
• Acetaminophen 15 mg/kg every 4-6 hours (maximum 650 mg per dose) alternative 4
• Nasal spray triptans (sumatriptan, zolmitriptan) for adolescents 12-17 years 4

Preventive Therapy Indications

Initiate prophylactic treatment for:

• Chronic migraine (≥15 headache days/month with ≥8 migraine days) 7, 1
• Frequent episodic migraine interfering with function despite optimized acute treatment 4
• Chronic tension-type headache (amitriptyline first-line) 1

Referral Criteria

Emergency admission (immediate):

• Any red flag present (thunderclap headache, focal neurological signs, papilledema, altered consciousness, meningeal signs) 1, 2
• Patient unable to self-care without help 1

Urgent neurology referral (within 48 hours):

• Suspected spontaneous intracranial hypotension 1
• Patient unable to self-care but has help available 1

Urgent specialist referral (within 1 month):

• Diagnosis uncertain 1
• First-line treatments fail 1
• Rapid clinical deterioration 1

Routine neurology referral (2-4 weeks):

• Suspected primary headache disorder requiring specialist confirmation 1
• Need for preventive therapy 1, 4
• Insufficient pain relief from acute medication 4

Rheumatology referral:

• Suspected giant cell arteritis (ESR/CRP elevated, age >50, temporal artery tenderness, jaw claudication) 1

Special Populations: Pediatric Considerations

Key differences in children:

• Migraine attacks are shorter (2-72 hours), often bilateral, and frequently accompanied by gastrointestinal symptoms 4
• 94% of children with brain tumors have abnormal neurological findings at diagnosis; 60% have papilledema 7, 4
• Neuroimaging yield is <1% for clinically significant findings in children with normal examination and no red flags 7, 4
• Cranial autonomic symptoms occur in 62% of pediatric migraineurs, leading to frequent misdiagnosis as "sinus headache" 7, 4
• Occipital location is rare in children and warrants caution 4

Pediatric-specific red flags:

• Posterior fossa signs (cerebellar dysfunction, gait abnormalities) 4
• Increased head circumference in infants <1 year (may prevent rapid symptom development from increased intracranial pressure) 7