What is the diagnostic approach for migraines?

Diagnosing Migraines: A Systematic Approach

The diagnosis of migraine is primarily based on a detailed medical history, with physical examination serving mainly to exclude secondary causes of headache. 1

Clinical Features to Identify Migraine

Migraine Without Aura

• Suspect migraine without aura in patients with recurrent moderate to severe headache, particularly if pain is unilateral and/or pulsating, with accompanying symptoms such as photophobia, phonophobia, nausea, and/or vomiting 1
• Headache attacks typically last 4-72 hours 1
• Pain is aggravated by routine physical activity 1
• Bilateral pain occurs in approximately 40% of migraine cases 1
• Prodromal symptoms may include depressed mood, yawning, fatigue, and food cravings 1
• Postdromal symptoms can last up to 48 hours and often include tiredness, concentration difficulties, and neck stiffness 1

Migraine With Aura

• Suspect migraine with aura in patients with recurrent, short-lasting visual and/or hemisensory disturbances that precede or accompany headache 1
• Visual aura occurs in >90% of affected individuals, classically as fortification spectra 1
• Sensory symptoms occur in ~31% of patients, usually as unilateral paresthesia that spreads gradually in the face or arm 1
• Aura symptoms typically develop gradually over ≥5 minutes, last 5-60 minutes, and may be followed by headache within 60 minutes 1

Chronic Migraine

• Suspect chronic migraine in patients with ≥15 headache days per month for >3 months 1
• At least 8 days per month should have features of migraine 1

Diagnostic Algorithm

Step 1: Comprehensive Medical History

Obtain the following essential information:

• Age at onset of headache 1
• Duration of headache episodes 1
• Frequency of headache episodes 1
• Pain characteristics (location, quality, severity, aggravating factors, relieving factors) 1
• Accompanying symptoms (photophobia, phonophobia, nausea, vomiting) 1
• Aura symptoms, if any 1
• History of acute and preventive medication use 1
• Family history of migraine 1

Step 2: Apply POUND Mnemonic

The POUND mnemonic is highly effective for diagnosing migraine 2:

• Pulsating quality
• Duration of 4-72 hOurs
• Unilateral location
• Nausea or vomiting
• Disabling intensity

If 4 of these 5 criteria are met, the likelihood ratio for definite or possible migraine is 24; if 3 are met, the likelihood ratio is 3.5 2

Step 3: Apply ICHD-3 Criteria

Apply the International Classification of Headache Disorders (ICHD-3) criteria to confirm the diagnosis 1

Step 4: Physical Examination

• Perform a neurological examination to exclude secondary headache disorders 1
• Physical examination is most often confirmatory rather than diagnostic 1

Step 5: Consider Diagnostic Aids

• Headache diaries are valuable for recording pattern and frequency of headaches and accompanying symptoms 1
• Headache calendars help track temporal occurrence of headaches and related events such as menstruation 1
• Screening questionnaires like ID-Migraine (three questions about nausea, photophobia, and disability) or Migraine Screen Questionnaire (MS-Q) can help identify likely migraine cases 1

Step 6: Consider Neuroimaging

Neuroimaging is indicated when there are red flags suggesting secondary headache 3, 2:

• Recent head or neck injury 3
• New, worse, worsening, or abrupt onset headache 3
• Headache brought on by Valsalva maneuver, cough, or exertion 3, 2
• Headache associated with sexual activity 3
• Headache in patients over age ~50 3
• Neurological findings or symptoms 3, 2
• Systemic signs or symptoms 3
• Secondary risk factors such as cancer or HIV infection 3
• Cluster-type headache 2
• Undefined headache (not cluster, migraine, or tension-type) 2
• Headache with vomiting 2

Common Pitfalls in Migraine Diagnosis

• Misdiagnosis of secondary headache: Always consider red flags that might indicate a secondary cause requiring neuroimaging 3, 2
• Overlooking medication overuse headache: Consider this diagnosis in patients with headache on ≥15 days/month and regular overuse of acute headache medications for >3 months 1
• Failure to recognize chronic migraine: This is defined as headache on ≥15 days/month for >3 months, with migraine features on ≥8 days/month 1
• Ignoring family history: Migraine has a strong genetic component, and a positive family history strengthens the diagnosis 1
• Relying solely on unilateral pain as a diagnostic feature: Bilateral pain occurs in approximately 40% of migraine cases 1
• Missing probable migraine: Consider "probable migraine" diagnosis for migraine-like attacks missing one feature required to fulfill all criteria 1