Laboratory Work for Migraine Diagnosis and Management

Introduction to Migraine Diagnosis

The American Academy of Neurology 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

Thunderclap headache or "worst headache of life" is a red flag symptom that requires laboratory workup 1
New-onset headache after age 50 is a red flag symptom that requires laboratory workup 2, 3
Progressive headache worsening over time is a red flag symptom that requires laboratory workup 1
Headache that awakens patient from sleep is a red flag symptom that requires laboratory workup 2, 3
Headache worsened by Valsalva maneuver is a red flag symptom that requires laboratory workup 2, 3
Unexplained abnormal neurological examination findings are a red flag symptom that requires laboratory workup 2, 3
Unexplained fever or neck stiffness is a red flag symptom that requires laboratory workup 1
Focal neurological symptoms or altered consciousness are red flag symptoms that require laboratory workup 1

Thyroid function tests (TSH, free T4) are recommended to evaluate for hypothyroidism or hyperthyroidism that can cause headaches 4
Complete blood count (CBC) is recommended to evaluate for anemia or hematologic abnormalities 4
Basic metabolic panel is recommended to evaluate for electrolyte disturbances, kidney function, and glucose levels 4
Erythrocyte sedimentation rate (ESR) is recommended if temporal arteritis is suspected in patients over 50 4
Liver function tests are recommended to rule out hepatic causes of headache 4
Serum calcium is recommended to evaluate for hyperparathyroidism 4
Urinary drug screen is recommended to rule out illicit substances (cocaine, amphetamines) that can cause headaches 4

Brain MRI with and without contrast is the preferred diagnostic study when secondary causes must be excluded, not laboratory tests 2, 4
MRI is indicated when red flags are present, particularly unexplained neurological findings, progressive symptoms, or atypical features 2, 3
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

Do not order routine laboratory panels for straightforward migraine cases, as 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, as 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

Headache diary documenting frequency, duration, intensity, and associated symptoms (nausea, photophobia, phonophobia) is valuable for migraine management 1, 5
Medication use tracking to identify potential medication overuse headache (analgesics >15 days/month or triptans >10 days/month) is valuable for migraine management 5
Assessment tools like HIT-6 (Headache Impact Test) or MSQ (Migraine-Specific Quality-of-Life Questionnaire) are valuable for measuring disability and treatment response 5