Migraine

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 Migraine: 

Definition

Migraine is a primary headache disorder characterized by recurrent episodes of head pain, typically unilateral and localized, often associated with nausea, vomiting, photophobia (sensitivity to light), and phonophobia (sensitivity to sound). Approximately 25% of migraine patients experience an aura, which consists of transient, reversible neurological symptoms preceding or accompanying the headache. Migraine is primarily a clinical diagnosis, and neuroimaging is generally not required unless atypical features or “red flags” are present.

Epidemiology

  • Prevalence:

    • Women: ~17%

    • Men: ~6%

  • Peak incidence: 30–39 years

  • Relative frequency: Second most common type of headache; most common cause among patients presenting to emergency departments with headache.

Etiology

The exact cause of migraine remains incompletely understood, but it is thought to involve a combination of genetic susceptibility and environmental triggers.

Genetic Predisposition

  • Individuals with migraine may have hyperexcitable brains due to altered neuronal habituation.

  • Familial cases, especially hemiplegic migraine, demonstrate autosomal dominant inheritance patterns.

Common Triggers

  • Dietary: chocolate, alcohol, tyramine-containing foods, dairy, citrus, nicotine

  • Lifestyle: fasting, dehydration, poor sleep, stress

  • Hormonal: menstruation, hormonal therapy (oral contraceptives)

  • Environmental: weather changes, sensory stimuli (light, noise)

Pathophysiology

Migraine involves complex neurovascular and neuroinflammatory mechanisms:

  1. Activation of meningeal nociceptors

    • Leads to pain perception.

  2. Trigeminovascular pathway activation

    • Trigeminal neurons release vasoactive peptides (substance P, CGRP) → vasodilatation and neurogenic inflammation.

  3. Cortical spreading depression (CSD)

    • Waves of cortical excitation and inhibition → activation of meningeal nociceptors, triggering aura.

  4. Autonomic system dysregulation

    • Hypothalamic responses to stress or hormonal changes influence cranial vascular tone and parasympathetic output.

  5. Vasodilation

    • Considered secondary, not the primary cause of pain.

Clinical Features

Migraine attacks typically follow four stages, though not all stages occur in every patient.

1. Prodrome (24–48 hours before headache)

  • Mood changes (irritability, euphoria, depression)

  • Fatigue or excessive yawning

  • Food cravings or anorexia

  • Difficulty concentrating, reading, or writing

2. Aura (25% of cases)

  • Typical aura: fully reversible, lasts ≤ 60 minutes

    • Visual: scintillating scotoma, flashing lights, fortification spectra, central scotoma, color distortion

    • Sensory: paresthesia, numbness

    • Speech: dysphasia/aphasia

    • Gradual onset, spreads over minutes

  • Atypical aura: may include paresis, persistent or prolonged symptoms, cranial nerve III palsy (rare, usually with vascular lesions)

3. Headache

  • Localization: usually unilateral, but may be bilateral; commonly frontal, frontotemporal, or retro-orbital

  • Duration: 4–24 hours, rarely >72 hours

  • Character: pulsating, throbbing, or pounding

  • Exacerbating factors: physical activity, movement

  • Associated symptoms: nausea, vomiting, photophobia, phonophobia

Mnemonic: “POUND” – Pulsatile, One-day duration, Unilateral, Nausea, Disabling intensity

4. Postdrome

  • Fatigue, euphoria, muscle weakness, anorexia or cravings

Migraine Subtypes and Variants

  1. Migraine with aura – includes visual, sensory, speech, or motor symptoms

  2. Migraine without aura – no preceding neurological symptoms

  3. Hemiplegic migraine – motor weakness in aura, may be familial or sporadic

  4. Brainstem aura (basilar-type) – reversible brainstem symptoms (vertigo, dysarthria, diplopia), no motor deficits

  5. Vestibular migraine – episodic vertigo associated with migraine

  6. Retinal migraine – monocular visual symptoms, fully reversible

  7. Silent migraine – aura occurs without headache

  8. Chronic migraine – ≥15 headache days/month for ≥3 months; ≥8 days with migraine features

  9. Menstrual migraine – linked to menstrual cycle; can be pure (only during menstruation) or menstrually related

Diagnosis

Clinical

  • Diagnosis is based on history and physical examination.

  • Rule out “red flags” suggesting secondary headaches (e.g., infection, hemorrhage, intracranial mass).

Diagnostic Criteria (ICHD-3)

Feature Migraine without aura Migraine with aura
Attacks ≥5 lifetime ≥2 lifetime
Duration 4–72 hrs N/A
Characteristics ≥2: unilateral, pulsating, moderate/severe, worsened by activity ≥1 aura symptom (visual, sensory, speech, motor, brainstem, retinal)
Concomitant ≥1: nausea/vomiting, photophobia, phonophobia ≥3 aura features: gradual spread ≥5 min, multiple aura in succession, each 5–60 min, unilateral, positive symptoms; headache within 60 min

Investigations

  • Laboratory tests: usually not indicated; pregnancy test in women of childbearing age

  • Imaging: MRI preferred if red flags present or atypical features (e.g., first aura after age 40, prolonged aura, change in baseline pattern)

  • Peripheral findings: usually normal; nonspecific white-matter changes may be seen

Differential Diagnosis

  • Paroxysmal hemicrania

  • Medication overuse headache

  • TIA or stroke in atypical aura

Management

Acute Treatment

General Measures

  • Reduce sensory stimuli (light/noise)

  • Rest in a dark, quiet room

  • Ensure adequate hydration

Mild–Moderate Headache

  • NSAIDs (ibuprofen, aspirin)

  • Acetaminophen

  • Combination therapy with caffeine (e.g., acetaminophen-aspirin-caffeine)

  • Parenteral NSAIDs if nausea/vomiting (ketorolac, diclofenac)

Moderate–Severe Headache

  • First-line: Triptans (sumatriptan, zolmitriptan) orally, subcutaneously, or intranasally

  • Second-line: Ergot alkaloids (dihydroergotamine)

  • Adjuncts: Antiemetics (metoclopramide, prochlorperazine), IV dexamethasone to prevent recurrence

Caution: Avoid opioids as first-line therapy; monitor for serotonin syndrome if combining triptans with other serotonergic drugs.

Migraine Prophylaxis

Indications

  • ≥3 attacks/month or attacks with severe disability

  • Poor response to acute therapy

  • Specific subtypes (hemiplegic, brainstem aura)

  • Contraindication to acute therapy

Non-Pharmacologic

  • Lifestyle modifications: regular sleep, moderate exercise, trigger avoidance, healthy diet

  • Behavioral therapy: relaxation, biofeedback, CBT

  • Acupuncture or noninvasive neuromodulation (adjunctive evidence)

Pharmacologic

  • Beta-blockers: propranolol, metoprolol

  • Anticonvulsants: topiramate, valproate

  • Antidepressants: amitriptyline, venlafaxine

  • CGRP-targeted therapies: monoclonal antibodies (erenumab, fremanezumab), oral antagonists (ubrogepant, rimegepant)

  • Others: candesartan, botulinum toxin for chronic migraine

Menstrual Migraine

  • Short-term prophylaxis with triptans (frovatriptan preferred) for 5–7 days around menstruation

  • Continuous combined hormonal contraception can be considered in women without aura

  • Migraine with aura is an absolute contraindication for estrogen-containing contraceptives

Special Populations

Pregnancy

  • Acute: acetaminophen first-line; sumatriptan has evidence for safety

  • Avoid: NSAIDs in 3rd trimester, opioids, ergot derivatives

  • Prophylaxis: calcium channel blockers, cyproheptadine; avoid beta-blockers unless specialist-approved

Children

  • Shorter attack duration (2–72 hours), often bilateral headaches

  • Aura uncommon; photophobia/phonophobia inferred from behavior

  • Treatment: ibuprofen preferred; triptans for older children (≥6 yrs)

  • Avoid aspirin (Reye syndrome risk)

  • Preventive therapy: lifestyle, amitriptyline + CBT, topiramate, propranolol

Complications

  • Status Migrainosus: debilitating migraine lasting ≥72 hours; may require hospitalization

    • Stepwise treatment: IV fluids, antiemetics, NSAIDs, dihydroergotamine, dexamethasone, valproate, magnesium sulfate (under specialist guidance)

  • Medication overuse headache

  • Rare: persistent neurological deficits, vascular events in migraine with aura

Summary of Acute Management Checklist

  1. Evaluate for red flags → consider imaging if indicated.

  2. Reduce sensory stimuli and maintain hydration.

  3. Initiate pharmacologic therapy early:

    • Mild–moderate: NSAIDs, acetaminophen

    • Moderate–severe: triptans or ergot alkaloids + antiemetics

    • Prevent recurrence: IV dexamethasone

  4. Status migrainosus: escalate therapy, consider hospitalization.

  5. Counsel on lifestyle modification and preventive strategies.

Disposition and Follow-Up

  • Most patients can be managed outpatient.

  • Hospitalize for:

    • Status migrainosus refractory to initial therapy

    • Inability to maintain hydration/nutrition

    • Chronic migraine with medication overuse requiring supervised withdrawal

  • Neurology or headache clinic referral for:

    • Frequent, severe, or disabling migraines

    • Preventive therapy optimization


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