What are the red flag symptoms of migraines?

Red Flag Symptoms of Migraines

The most critical red flag symptoms of migraines that require urgent medical evaluation include sudden onset severe headache ("thunderclap"), focal neurological deficits, headache onset after age 50, and headache that awakens patients from sleep. 1

Key Red Flags in Patient History

• Thunderclap headache: Sudden onset headache reaching maximum intensity within seconds to minutes may indicate subarachnoid hemorrhage 1
• "Worst headache of life": Abrupt onset of severe headache may indicate serious vascular pathology 1
• Marked change in headache pattern: Significant change in previously stable headache characteristics requires further investigation 1
• Atypical aura: May indicate transient ischemic attack, stroke, epilepsy, or arteriovenous malformations 1
• Progressive headache: Worsening over time could indicate an intracranial space-occupying lesion 1
• Headache aggravated by Valsalva maneuvers: Headaches worsened by coughing, sneezing, or exercise could indicate increased intracranial pressure 2, 1
• Headache onset after age 50: Suggests secondary headache and consideration of temporal arteritis 1
• Headache that awakens patient from sleep: May indicate increased intracranial pressure 1
• Persistent headache following head trauma: May indicate intracranial injury 2, 1
• Headache associated with weight loss and/or change in memory/personality: Suggests secondary headache 1

Red Flags on Physical Examination

• Unexplained fever: May indicate meningitis or systemic infection 1
• Neck stiffness: Possible indicator of meningitis or subarachnoid hemorrhage 1
• Focal neurological signs: Suggest secondary headache and require urgent evaluation 2, 1
• Papilledema: Indicates increased intracranial pressure 3
• Impaired memory, altered consciousness, or personality changes: Suggests secondary headache 1
• Uncoordination: May indicate cerebellar pathology 2, 1

Clinical Significance and Approach

• Neuroimaging is indicated when red flags are present to rule out secondary causes of headache 1
• MRI is preferred over CT due to higher resolution and absence of radiation exposure, except when acute intracranial hemorrhage is suspected, then CT without contrast is recommended 1
• The American Academy of Neurology suggests that neuroimaging should be considered in patients with migraine who have atypical headache patterns or neurologic signs 2

Distinguishing from Typical Migraine Features

Typical migraine features (not red flags) include:

• Recurrent headache attacks lasting 4-72 hours 2
• Unilateral location, pulsating quality, moderate to severe intensity 2
• Aggravation by routine physical activity 2
• Associated symptoms like nausea, vomiting, photophobia, and phonophobia 2, 4
• Fully reversible aura symptoms (visual, sensory, speech/language) that develop gradually and last 5-60 minutes 2

Common Pitfalls to Avoid

• Overlooking the need for neuroimaging when red flags are present 1
• Assuming that a patient with a history of migraine cannot develop a secondary headache disorder 3
• Failing to recognize that sumatriptan and other triptans are contraindicated in patients with cerebrovascular events, as these medications may cause cerebral hemorrhage, subarachnoid hemorrhage, and stroke 5
• Missing the diagnosis of medication overuse headache, which can present as migraine-like daily headaches or increased frequency of migraine attacks 5

Remember that while migraine is a common primary headache disorder, the presence of any red flag symptoms warrants further investigation to rule out potentially life-threatening secondary causes of headache 2, 1, 6.