What tests should be ordered for a patient with aura, headache, and peripheral vision changes?

Diagnostic Testing for Aura with Headache and Peripheral Vision Changes

For a patient presenting with aura, headache, and peripheral vision changes, the primary diagnostic approach is clinical—based on history and examination using ICHD-3 criteria—and neuroimaging is NOT routinely required if the presentation is consistent with typical migraine with aura. 1

Clinical Diagnosis First

The diagnosis of migraine with aura is fundamentally clinical and does not require imaging in typical presentations. 1

• The key diagnostic features to establish are: gradual onset of visual symptoms over ≥5 minutes, duration of 5-60 minutes per symptom, complete reversibility, and headache following within 60 minutes 1, 2
• Visual aura occurs in over 90% of patients with aura and includes positive phenomena (scintillations, fortification spectra, bright dots) or negative phenomena (scotoma) 2, 3
• At least 2 attacks fulfilling these criteria are required for diagnosis 1

When Neuroimaging IS Indicated

Brain MRI (not CT) should be ordered urgently if any atypical features are present that suggest a secondary cause rather than primary migraine. 4

Red Flags Requiring Immediate Imaging:

• Sudden, simultaneous onset of symptoms rather than gradual spread over ≥5 minutes (suggests TIA or stroke) 2, 3
• Prolonged visual aura lasting >60 minutes (suggests structural lesion such as occipital AVM) 3, 4
• First-time aura in a patient where onset timing cannot be clearly established as gradual 3
• Late-onset migraine-like headaches (after age 50) with new visual symptoms 4
• Neurological symptoms corresponding to a single vascular territory rather than spreading pattern 3
• Dramatic increase in aura attack frequency 3
• Associated seizures 4

Specific Testing Algorithm

For Typical Migraine with Aura Presentation:

• No imaging required 1
• Diagnosis based on ICHD-3 criteria application through detailed history 1
• Consider headache diary for diagnostic confirmation and monitoring 1

For Atypical or First-Time Presentations:

• MRI brain with and without contrast is the preferred imaging modality if secondary causes must be excluded 4, 5
• MRI can detect structural lesions (AVM, tumor), perfusion changes, and dilated veins in susceptibility-weighted imaging that may indicate cortical spreading depression 5
• CT head is inadequate for evaluating most causes of visual aura and should not be the primary imaging choice 1

For Acute Vestibular Symptoms:

• If the patient has acute vestibular syndrome (continuous vertigo >24 hours) rather than typical visual aura, imaging may be needed to exclude posterior circulation stroke, particularly if HINTS examination is unavailable or abnormal 1
• However, vestibular migraine with visual aura typically does not require imaging if diagnostic criteria are met 1

Critical Pitfalls to Avoid

• Do not order routine neuroimaging for typical migraine with aura—this leads to unnecessary testing, cost, and potential false-positive findings 1
• Do not rely on CT to exclude serious pathology in patients with visual aura—MRI is far superior for detecting AVMs, small infarcts, and other structural causes 4, 5
• Do not dismiss prolonged aura (>60 minutes) as "just migraine"—this requires urgent imaging to exclude stroke, AVM, or other structural lesions 3, 4
• Do not confuse gradual spreading (migraine) with sudden onset (TIA)—the temporal pattern is the key distinguishing feature 2, 3