What is the appropriate evaluation and treatment for a new‑onset severe headache with possible red‑flag features?

Severe New-Onset Headache: Evaluation and Treatment

For a new-onset severe headache, immediately assess for red-flag features that mandate urgent neuroimaging and rule out life-threatening causes before considering primary headache treatment.

Immediate Red-Flag Assessment

Critical red flags requiring urgent evaluation include: 1

• Thunderclap onset (abrupt, reaching maximum intensity within seconds to minutes) – suggests subarachnoid hemorrhage 1
• Rapidly increasing frequency or progressive worsening 1
• Marked change in headache pattern from any prior headaches 1
• Persistent headache following head trauma 1
• Headache awakening patient from sleep 1
• Fever with neck stiffness – suggests meningitis 1
• Focal neurological signs or symptoms (weakness, numbness, vision changes) 1, 2
• Altered mental status or impaired consciousness 2, 3
• New headache in patient >50 years 4, 2, 3
• Headache aggravated by Valsalva maneuver, coughing, or sneezing 1, 4
• Sudden unilateral hearing loss (suggests arterial dissection) 1

Neuroimaging Decision Algorithm

If ANY red flag is present: 1

1. Order MRI brain without contrast immediately – this is the preferred first-line imaging modality with 4% diagnostic yield versus <1% for CT 1, 5
2. If MRI unavailable or significantly delayed, obtain non-contrast CT head – recognizing it has 98% sensitivity for acute subarachnoid hemorrhage but misses most posterior circulation strokes 1, 5
3. Do NOT rely on normal neurologic examination alone – 75-80% of patients with posterior circulation stroke have no focal deficits 6

If NO red flags are present and headache meets criteria for primary headache disorder (migraine, tension-type): 1

• Neuroimaging is not indicated 1
• Proceed directly to acute treatment 1, 5

Acute Treatment for Primary Headache (After Excluding Secondary Causes)

First-Line Treatment

For mild-to-moderate severity: 1, 5

• NSAIDs: Ibuprofen 400-800 mg, naproxen sodium 500-825 mg, or aspirin 1000 mg 1, 5
• Combination therapy: Acetaminophen 1000 mg + aspirin 500-1000 mg + caffeine 130 mg achieves pain reduction in 59.3% at 2 hours 5

For moderate-to-severe severity or NSAID failure: 1, 5

• Triptans: Sumatriptan 50-100 mg, rizatriptan 10 mg, or eletriptan 40 mg 1, 5
• Take early when pain is still mild for maximum effectiveness 1
• Combination approach: Triptan + NSAID is superior to either alone 1, 5

Parenteral Options for Severe Headache with Vomiting

IV "headache cocktail": 5

• Metoclopramide 10 mg IV – provides direct analgesic effects beyond antiemetic properties 5
• Ketorolac 30 mg IV (or 60 mg IM if <65 years) – rapid onset, 6-hour duration, minimal rebound risk 1, 5
• Prochlorperazine 10 mg IV – comparable efficacy to metoclopramide 5

Critical Medication Frequency Limit

Limit ALL acute headache medications to ≤2 days per week (≤10 days per month) to prevent medication-overuse headache, which paradoxically increases headache frequency and can lead to daily headaches. 1, 5

Medications to Absolutely Avoid

Never prescribe for acute headache: 1, 5

• Opioids (hydrocodone, oxycodone, meperidine, hydromorphone) – questionable efficacy, high risk of dependence, rebound headaches, and medication-overuse headache 1, 5
• Butalbital-containing compounds – high risk of medication-overuse headache and dependency 1, 5
• Oral ergot alkaloids – poorly effective and potentially toxic 1

Essential History Elements

Document these specific details: 1

• Time to peak intensity – seconds suggests thunderclap/SAH, minutes-to-hours suggests migraine 7, 8
• Duration – hours versus days 1
• Location – unilateral versus bilateral, frontal versus occipital 1
• Character – throbbing, stabbing, pressure-like 1
• Associated symptoms – nausea/vomiting, photophobia, phonophobia, visual changes 1
• Triggers – exertion, sexual activity, position changes 1, 4
• Prior headache history – frequency, pattern, previous diagnoses 1
• Medication history – current analgesic use frequency (to assess for medication-overuse) 1, 5

Common Diagnostic Pitfalls to Avoid

• Do not assume normal neurologic exam excludes serious pathology – most posterior circulation strokes present without focal deficits 6
• Do not use CT as substitute for MRI when stroke suspected – CT misses majority of posterior circulation infarcts 1, 5, 6
• Do not allow patients to increase acute medication frequency when treatment fails – this creates medication-overuse headache cycle; instead initiate preventive therapy 1, 5
• Do not prescribe opioids simply because patient requests them or reports "nothing else works" without ensuring adequate trials of NSAIDs and triptans first 5

When to Refer to Neurology

Immediate referral indicated for: 1

• Any positive neuroimaging finding
• Refractory headaches requiring >2 days/week of acute medication despite optimization
• Atypical features not fitting primary headache criteria
• Need for preventive therapy initiation