Migraine

Introduction
Migraine is a common, chronic neurological disorder characterized by recurrent episodes of moderate-to-severe headache, often accompanied by sensory disturbances. Attacks can last from 4 to 72 hours and are frequently associated with nausea, vomiting, photophobia (sensitivity to light), and phonophobia (sensitivity to sound). Migraines can be disabling, affecting quality of life and daily functioning, and are classified among the most burdensome neurological disorders worldwide.

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Epidemiology

• Affects around 12–15% of the global population.

• More common in women than men (approximately 3:1 ratio).

• Often begins in adolescence or early adulthood.

• Peak prevalence between 25 and 55 years of age.

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Pathophysiology

Migraine is believed to involve a combination of genetic, vascular, and neurological factors.
Key mechanisms include:

• Cortical spreading depression: A wave of neuronal and glial depolarization spreading across the cortex, associated with aura symptoms.

• Trigeminovascular activation: Stimulation of the trigeminal nerve leading to release of vasoactive neuropeptides (CGRP, substance P), causing inflammation and vasodilation of cranial blood vessels.

• Serotonin (5-HT) imbalance: Altered serotonin signaling contributes to vascular and pain pathway changes during migraine.

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Types of Migraine

1. Migraine without Aura

   • Most common type.

   • Moderate-to-severe unilateral headache with pulsating quality.

2. Migraine with Aura

   • Aura refers to reversible focal neurological symptoms preceding or accompanying headache.

   • Common aura symptoms: visual disturbances (flashing lights, zigzag lines), sensory symptoms (numbness, tingling), speech disturbances.

3. Chronic Migraine

   • Headache occurring on ≥15 days per month for >3 months, with migraine features on at least 8 days/month.

4. Migraine with Brainstem Aura

   • Aura symptoms include vertigo, tinnitus, dysarthria, diplopia, without motor weakness.

5. Hemiplegic Migraine

   • Rare; aura includes motor weakness.

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Triggers

Common migraine triggers include:

• Dietary: Alcohol (especially red wine), aged cheese, processed meats, caffeine overuse or withdrawal, MSG.

• Hormonal: Menstrual cycle fluctuations, pregnancy, menopause.

• Environmental: Bright lights, loud sounds, strong odors, weather changes.

• Lifestyle: Stress, irregular sleep, skipping meals, dehydration.

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Clinical Features

Headache Phase

• Typically unilateral (but can be bilateral).

• Pulsating or throbbing pain.

• Moderate to severe intensity.

• Aggravated by physical activity.

Associated Symptoms

• Nausea and/or vomiting.

• Photophobia and phonophobia.

• Neck stiffness in some cases.

Aura Phase (if present)

• Develops gradually over 5–20 minutes.

• Lasts less than 60 minutes.

Prodrome and Postdrome

• Prodrome: Hours to days before attack; mood changes, food cravings, fatigue.

• Postdrome: After headache resolves; tiredness, difficulty concentrating, mild residual pain.

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Diagnosis

Diagnosis is clinical, based on International Classification of Headache Disorders (ICHD-3) criteria.
Investigations may be performed to exclude secondary causes in atypical or first-time presentations:

• MRI or CT head.

• Blood tests if indicated.

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Management

Goals:

• Relieve acute attacks.

• Prevent future attacks (prophylaxis).

• Improve quality of life.

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1. Acute (Abortive) Treatment

Simple Analgesics

• Paracetamol: 1000 mg orally at onset (max 4 g/day).

• Ibuprofen: 400–600 mg orally at onset; can repeat every 6–8 hours (max 2400 mg/day).

• Naproxen: 500–550 mg orally initially, then 250 mg every 6–8 hours as needed.

Triptans (serotonin 5-HT₁B/₁D receptor agonists – specific anti-migraine drugs)

• Sumatriptan: 50–100 mg orally at onset; may repeat after 2 hours (max 200 mg/day) or 6 mg SC once (max 12 mg/day).

• Rizatriptan: 10 mg orally at onset; may repeat after 2 hours (max 30 mg/day).

• Zolmitriptan: 2.5–5 mg orally at onset; may repeat after 2 hours (max 10 mg/day).

Antiemetics (for nausea/vomiting and to improve analgesic absorption)

• Metoclopramide: 10 mg orally or IM at onset, up to 3 times/day.

• Prochlorperazine: 5–10 mg orally or buccally at onset, up to 3 times/day.

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2. Preventive (Prophylactic) Treatment

Considered if:

• ≥4 attacks/month, or

• Attacks significantly interfere with life despite acute treatment, or

• Acute treatments are contraindicated or ineffective.

Beta-blockers

• Propranolol: 40 mg twice daily, titrate to 80–160 mg/day.

Antidepressants

• Amitriptyline: 10–25 mg at night; may increase to 50–75 mg/day.

Anticonvulsants

• Topiramate: Start 25 mg nightly; titrate to 50–100 mg/day in divided doses.

• Valproate: 250–500 mg twice daily (avoid in pregnancy).

CGRP Monoclonal Antibodies (for resistant cases)

• Erenumab: 70–140 mg SC once monthly.

• Fremanezumab: 225 mg SC monthly or 675 mg every 3 months.

Calcium Channel Blockers

• Flunarizine: 5–10 mg at night (not available in all countries).

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3. Lifestyle and Trigger Management

• Keep a headache diary to identify and avoid triggers.

• Maintain regular sleep, meals, and hydration.

• Manage stress with relaxation techniques or cognitive-behavioural therapy (CBT).

• Regular moderate exercise.

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Complications

• Medication overuse headache (from frequent analgesic use).

• Status migrainosus (severe migraine lasting >72 hours).

• Increased risk of ischemic stroke in migraine with aura (especially in women <45 years who smoke and use oral contraceptives).

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Prognosis

• Migraine is a chronic disorder with variable frequency and severity.

• Many patients achieve good control with a combination of acute and preventive therapy.

• Some experience spontaneous remission over time.