Migraine Headaches

Detailed Overview

It is a highly disabling condition, ranking among the top causes of disability worldwide. About one-third of patients experience an aura—transient focal neurological symptoms (usually visual)—preceding the headache. The pathophysiology involves trigeminovascular system activation and calcitonin gene-related peptide (CGRP) release. Management is divided into acute abortive therapy to stop attacks and prophylactic therapy to reduce their frequency.

Epidemiology & Demographics

Global prevalence is ~15%. Three times more common in women (18%) than men (6%). Peak incidence occurs between ages 25 and 55, causing significant occupational disability.

Etiological Mechanism

A complex interplay of genetic and environmental factors resulting in a state of neuronal hyperexcitability. A strong family history is present in 70-80% of sufferers.

Primary Causes

Triggers include hormonal fluctuations (menstruation), stress, lack of sleep, sensory stimuli (bright lights, strong smells), and certain foods (aged cheese, alcohol, MSG).

• Female Sex: Estrogen fluctuations tightly regulate migraine frequency, often peaking perimenstrually.
• Family History: Polygenic inheritance; having a parent with migraines significantly increases risk.
• High Stress / Poor Sleep: Shift work, sleep apnea, or high anxiety environments are potent triggers.

Migraine involves primary neuronal dysfunction. It begins with Cortical Spreading Depression (CSD), a wave of neuronal depolarization followed by sustained depression, which correlates with the aura. This activates the Trigeminal Cervical Complex. The trigeminal nerve endings in the meninges release potent vasodilators and inflammatory neuropeptides, most notably Calcitonin Gene-Related Peptide (CGRP) and Substance P. This causes neurogenic inflammation of the meningeal blood vessels, leading to the throbbing pain, which is transmitted back to the brainstem and thalamus (central sensitization).

Characteristic Clinical Presentation

• Pulsating Headache: Unilateral, moderate-to-severe throbbing pain that worsens with routine physical activity (e.g., walking stairs).
• Photophobia and Phonophobia: Extreme sensitivity to light and sound, causing the patient to seek a dark, quiet room.
• Visual Aura: Scintillating scotoma (flickering zig-zag lines) or spreading blind spots occurring 15-60 minutes before the headache.

Physical Examination Signs

• Patient often lies perfectly still in a dark room (contrast with cluster headache patients who pace)
• Cutaneous allodynia (pain from normal touch, like brushing hair, during a severe attack)
• Normal comprehensive neurologic exam between attacks

• Medication Overuse Headache (MOH): Rebound daily headaches caused by frequent use (>10-15 days/month) of acute abortive medications (triptans, NSAIDs).
• Status Migrainosus: A debilitating migraine attack lasting longer than 72 hours despite treatment.

Diagnostic Criteria & Guidelines

ICHD-3 Criteria for Migraine without Aura: At least 5 attacks fulfilling: 1) Lasting 4-72 hours. 2) Two of: unilateral, pulsating, moderate/severe intensity, aggravated by routine activity. 3) One of: nausea/vomiting, or photophobia AND phonophobia. 4) Normal neuro exam.

Differential Diagnosis

• Tension-Type Headache
• Cluster Headache
• Subarachnoid Hemorrhage ('Thunderclap' headache)
• Meningitis

Laboratory Tests & Biomarkers

• None: Diagnosis is strictly clinical. Labs (ESR/CRP) only if temporal arteritis is suspected in older patients.

Imaging Modalities & Findings

• MRI Brain: Usually normal. Indicated ONLY if 'red flags' are present (e.g., new abnormal neurologic exam, sudden onset thunderclap headache). May show benign non-specific white matter hyperintensities in chronic sufferers.

• Prodrome
  Hours to days before. Mood changes, food cravings, yawning, neck stiffness.
• Aura
  Present in 30%. Visual, sensory, or speech disturbances lasting 5-60 minutes.
• Headache Phase
  Throbbing pain, nausea, photophobia lasting 4-72 hours.
• Postdrome
  'Migraine hangover.' Fatigue, cognitive fogginess, and scalp tenderness lasting 24-48 hours.

Second-Line & Adjunctive Therapy

Abortive: CGRP receptor antagonists (Ubrogepant 50mg PO) or Lasmiditan. Preventive: Anti-CGRP monoclonal antibodies (Erenumab 70mg SubQ monthly, Fremanezumab) or Amitriptyline 10-25mg PO at bedtime.

Surgical & Procedural Management

Botulinum Toxin A (Botox) injections every 12 weeks for Chronic Migraine (≥15 headache days/month).

Recommended Lifestyle Changes

• Maintain a headache diary to identify and eliminate specific food or environmental triggers.
• Keep highly regular sleep and meal schedules; do not skip meals.
• Limit caffeine intake to < 200mg/day to prevent withdrawal headaches.

Patient Counseling & Advice

Warn strongly against taking acute abortive medications more than 2-3 days per week to prevent Medication Overuse Headache. Counsel women with Migraine WITH Aura to avoid estrogen-containing oral contraceptives due to increased stroke risk.

Follow-Up & Monitoring Schedule

Review headache diary every 3 months. Assess efficacy of preventive therapy (success is defined as a >50% reduction in headache frequency or severity).

Preventive Strategies

Initiate preventive daily medications if the patient experiences ≥ 4 debilitating headache days per month, or if acute treatments are contraindicated or overused.

Migraine is a chronic condition without a cure, but it is highly manageable. Frequency and severity often decrease naturally post-menopause in women and in later life for men.