What lab work is recommended for patients presenting with migraines?

Laboratory Work for Migraine

Routine laboratory tests are not recommended for typical migraine presentations, as migraine is a clinical diagnosis based on validated criteria, not laboratory findings. 1

When Laboratory Testing is NOT Indicated

• For uncomplicated migraine with normal neurological examination, no laboratory tests are warranted. 1
• The American Academy of Neurology specifically recommends against ordering unnecessary laboratory tests for typical migraine presentations without red flags. 1
• Migraine diagnosis should rely on clinical features using validated criteria from the International Headache Society, not laboratory investigations. 1
• Validated screening tools like the three-item ID-Migraine questionnaire (sensitivity 0.81, specificity 0.75) are more valuable than laboratory tests for diagnosis. 1

When Laboratory Testing IS Indicated

Laboratory work becomes necessary only when red flags suggest a secondary headache disorder rather than primary migraine. 1, 2

Red Flag Symptoms Requiring Workup:

• Thunderclap headache or "worst headache of life" 1
• New-onset headache after age 50 3, 2
• Progressive headache worsening over time 1
• Headache that awakens patient from sleep 3, 2
• Headache worsened by Valsalva maneuver 3, 2
• Unexplained abnormal neurological examination findings 3, 2
• Unexplained fever or neck stiffness 1
• Focal neurological symptoms or altered consciousness 1

Recommended Laboratory Tests When Red Flags Present:

Basic metabolic and hematologic screening:

• Thyroid function tests (TSH, free T4) - both hypothyroidism and hyperthyroidism can cause headaches 4
• Complete blood count (CBC) to evaluate for anemia or hematologic abnormalities 4
• Basic metabolic panel for electrolyte disturbances, kidney function, and glucose levels 4
• Erythrocyte sedimentation rate (ESR) if temporal arteritis suspected in patients over 50 4

Additional tests based on clinical suspicion:

• Liver function tests to rule out hepatic causes 4
• Serum calcium to evaluate for hyperparathyroidism 4
• Urinary drug screen to rule out illicit substances (cocaine, amphetamines) 4

Neuroimaging vs. Laboratory Tests

Brain MRI with and without contrast is the preferred diagnostic study when secondary causes must be excluded, not laboratory tests. 4, 2

• MRI is indicated when red flags are present, particularly unexplained neurological findings, progressive symptoms, or atypical features. 3, 2
• MRI is preferred over CT due to higher resolution and absence of radiation exposure. 2
• Neuroimaging is more valuable than laboratory work for ruling out structural causes (tumors, vascular malformations, inflammatory processes). 4

Common Pitfalls to Avoid

• Do not order routine laboratory panels for straightforward migraine cases - this leads to unnecessary costs and potential false-positive results requiring further workup. 1
• Do not rely on laboratory tests rather than clinical criteria for primary migraine diagnosis. 1
• Do not overlook the need for neuroimaging when red flags are present - laboratory tests alone are insufficient to rule out serious secondary causes. 1
• Consider lumbar puncture if increased intracranial pressure is suspected, especially with papilledema on fundoscopic examination. 4

What IS Valuable for Migraine Management

Instead of laboratory tests, focus on:

• Headache diary documenting frequency, duration, intensity, and associated symptoms (nausea, photophobia, phonophobia). 3, 1
• Medication use tracking to identify potential medication overuse headache (analgesics >15 days/month or triptans >10 days/month). 3
• Assessment tools like HIT-6 (Headache Impact Test) or MSQ (Migraine-Specific Quality-of-Life Questionnaire) to measure disability and treatment response. 3