FFS: Migraine Headache

Pathophysiology

The pathogenesis of migraine involves neurovascular mechanisms, with:

• Initial vasospasm → aura
• Subsequent vasodilation → headache

A central role is played by calcitonin gene-related peptide (CGRP):

• Potent vasodilator of cerebral vessels
• Involved in nociception

CGRP is released from trigeminal perivascular nerve endings, acting on CGRP receptors to mediate vasodilation and pain.

Classification

1. Migraine without aura (common migraine)

• No focal neurological symptoms
• Headache ≥2 of the following (PUMA):
  • Pulsatile
  • Unilateral
  • Moderate–severe intensity
  • Aggravated by movement
• Associated with:
  • Nausea/vomiting
  • Photophobia
  • Phonophobia
• Duration: 4–72 hours
• No alternative explanation

2. Migraine with aura (classic migraine)

• Reversible neurological symptoms precede/accompany headache
• Aura: 10–30 minutes, stereotyped
• Common symptoms:
  • Visual disturbances
  • Dizziness
  • Paraesthesiae
  • Unilateral limb weakness
  • Vertigo
  • Dysphasia
  • Mood changes

Less common types:

• Retinal / Ophthalmoplegic migraine
• Hemiplegic migraine
• Aura without headache (must be distinguished from TIA)
• Vestibular migraine
• Status migrainosus: attack >72 hours

Clinical Assessment

• Confirm diagnosis clinically
• Exclude serious secondary causes, especially if:
  • First migraine episode
  • Atypical features
  • Recurrent drug-seeking behaviour

Important history:

1. Is it a typical migraine episode?
2. Sudden onset? (SAH risk)
3. Anticoagulated patient? (risk of ICH)
4. Combined OCP + aura? (stroke risk)

Important examination findings:

• Fever → infectious cause
• Confusion → encephalitis
• Neck stiffness → meningitis / SAH
• Purpuric rash → meningococcus
• Focal neurology → stroke / space-occupying lesion

Complications

• Status migrainosus: dehydration, electrolyte disturbance
• Hemiplegia
• Visual field loss

Precipitating Factors

• Emotional stress (most common)
• Menstruation
• Sleep deprivation
• Alcohol

Investigations

None required if classic history and no red flags.

Consider CT / CTA brain if:

1. First-ever migraine
2. Atypical presentation
3. Neurological findings
4. Very acute onset
5. Anticoagulation
6. Failure to respond to adequate treatment

Management

Mild symptoms:

1. Simple analgesics
   • Aspirin 600–900 mg PO, soluble form preferred
   • NSAIDs (e.g. ibuprofen) are alternatives but not superior
   • Avoid codeine/oxycodone
2. Antiemetics
   • Metoclopramide 10 mg IV
   • Prochlorperazine 12.5 mg slow IV
   • Ondansetron 4 mg IV (can be used, despite theoretical concerns with triptans)

Moderate to severe symptoms:

1. Avoid opioids — not recommended for migraine
2. Triptans (most effective, specific migraine therapy)

Triptan	Dose	Max Daily Dose
Sumatriptan	50–100 mg PO; 10–20 mg IN; 6 mg SC	PO: 300 mg; IN: 40 mg; SC: 2 doses, ≥1 hr apart
Rizatriptan	10 mg wafer	30 mg
Eletriptan	40 mg PO, repeat after 2 hrs	160 mg
Naratriptan	2.5 mg PO, repeat ≥4 hrs	5 mg
Zolmitriptan	2.5 mg PO, may increase to 5 mg	10 mg

Contraindications for triptans:

• Ergotamine use in prior 24 hrs
• Significant coronary artery disease

3. Chlorpromazine
   • 25 mg IV in 1 L normal saline over 60 minutes
   • Monitor QTc — avoid in cardiac disease, electrolyte abnormalities
4. IV fluids — for dehydration, persistent vomiting
5. Supportive nursing
   • Quiet, dark room
   • Minimise stimulation

Migraine and Contraception

• Combined OCP is contraindicated in migraine with aura due to stroke risk
• Safe options:
  • Progestogen-only methods
• Combined OCP may be used in migraine without aura, with caution

Migraine Prophylaxis

Lifestyle

• Minimise known triggers (especially stress)
• Work–life balance changes may be needed

Pharmacological

Traditional options:

• Amitriptyline
• Beta-blockers
• Sodium valproate
• Topiramate
• Pizotifen
• Gabapentin

CGRP-based therapies:

• Receptor antagonists: Erenumab
• CGRP-binding antibodies: Eptinezumab, Fremanezumab, Galcanezumab

These reduce migraine days by ≥50% in many patients. Long-term safety still under evaluation.

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References

Publications

• Brazis PW, Masdeu JC, Biller J. Localization in Clinical Neurology. 8e 2021
• Fuller G. Neurological Examination Made Easy. 6e 2019

FOAMed

• Coni R. Migraine headache. LITFL
• Coni R. Headache classification. LITFL
• Coni R. Headache Essentials. LITFL