Are Magnetic Resonance Imaging (MRI) scans of the brain indicated in patients with migraines?

From the Guidelines

MRI brain scans are not routinely indicated for patients with typical migraine presentations. For patients with a stable pattern of headaches that meet diagnostic criteria for migraine, who have normal neurological examinations, and who respond to appropriate migraine treatments, neuroimaging is generally unnecessary 1. However, MRI brain scans should be considered in specific situations:

• when patients present with unusual, severe, or sudden-onset headaches;
• when migraines begin after age 50;
• when the pattern of headaches changes significantly;
• when neurological examination reveals abnormalities;
• when headaches are accompanied by concerning symptoms like seizures, altered mental status, or signs of increased intracranial pressure;
• or when patients have risk factors such as cancer, immunosuppression, or HIV. The rationale for selective imaging is that typical migraines are a primary headache disorder with a well-established pathophysiology involving neurovascular mechanisms, and the likelihood of finding clinically significant abnormalities on MRI in patients with typical migraines is very low 1. Unnecessary imaging increases healthcare costs, may cause patient anxiety, and can lead to incidental findings that result in further unnecessary testing. Some key points to consider when deciding to perform an MRI include:
• The presence of signs of increased intracranial pressure, which would necessitate an MRI with and without contrast 1
• The suspicion of a Chiari I deformity, which would require a noncontrast MRI scan of the brain to include a sagittal T2-weighted sequence of the cranio-cervical junction 1
• The presence of seizures, which would indicate an MRI without IV contrast 1
• The suspicion of venous sinus thrombosis or pseudotumor cerebri, which would require an MRI with and without contrast, as well as an MRV 1. It is essential to weigh the benefits and risks of imaging and to consider the clinical context and patient-specific factors when making decisions about neuroimaging in patients with migraines 1.

From the Research

Indications for MRI Brain in Migraine Patients

• MRI brain is not necessarily indicated in patients with migraines who have a normal neurologic examination and no atypical features or red flags present 2
• Neuroimaging may be considered for presumed migraine in certain situations, such as:
  • Unusual, prolonged, or persistent aura
  • Increasing frequency, severity, or change in clinical features
  • First or worst migraine
  • Migraine with brainstem aura, confusion, or motor manifestations (hemiplegic migraine)
  • Late-life migraine accompaniments
  • Aura without headache
  • Side-locked headache
  • Posttraumatic headache 2

Incidental Findings on MRI

• Incidental MRI findings were discovered in 57% of scans in a study of adult patients with chronic migraine, with 8.3% of these findings being clinically significant 3
• Patients aged over 40 years were more likely to have an abnormal scan 3
• Clinically significant MRI findings were found in up to 8% of patients with migraines who did not respond as expected to treatment 3

Relationship Between Migraine and Stroke

• There is an association between migraines and stroke, particularly between migraine with aura and ischemic stroke 4, 5
• Migraine with aura may increase the risk of ischemic stroke, especially in young women 4, 5
• White matter changes similar to those seen in patients with stroke may be found on imaging in migraine patients 4