What is the recommended initial imaging for migraine diagnosis?

From the Guidelines

Neuroimaging is generally not recommended for the initial diagnosis of migraine in patients with typical headache features and a normal neurological examination. Migraine is primarily a clinical diagnosis based on history and physical examination findings [ 1 ]. Routine imaging studies such as CT scans or MRIs are unnecessary for patients with recurrent, stable headache patterns that meet migraine diagnostic criteria and who have no concerning features on neurological examination. However, neuroimaging should be considered when patients present with unusual, new, or particularly severe headaches, headaches that have changed in pattern or intensity, headaches associated with seizures, headaches with focal neurological deficits that persist beyond the aura phase, or headaches that worsen with Valsalva maneuvers [ 1 ]. The rationale for limiting imaging in typical migraine cases is to avoid unnecessary radiation exposure, reduce healthcare costs, prevent patient anxiety from incidental findings, and minimize false positives that could lead to additional unnecessary testing [ 1 ]. When imaging is indicated, MRI is generally preferred over CT because it provides better visualization of posterior fossa structures and does not involve radiation exposure [ 1 ].

Some key points to consider when evaluating a patient with migraine include:

• A thorough history and physical examination to identify any atypical features or red flags [ 1 ]
• The use of neuroimaging should be based on the presence of abnormal findings on neurologic examination or atypical headache patterns [ 1 ]
• The American Academy of Neurology and the U.S. Headache Consortium have developed guidelines for the use of neuroimaging in patients with migraine [ 1 ]
• Electroencephalography is not useful in the routine evaluation of patients with headache but may be appropriate in those who have associated symptoms suggestive of a seizure disorder [ 1 ]

In terms of specific imaging modalities, MRI is generally preferred over CT due to its better visualization of posterior fossa structures and lack of radiation exposure [ 1 ]. However, the choice of imaging modality will depend on the specific clinical scenario and the presence of any contraindications to MRI [ 1 ].

Overall, a thoughtful and individualized approach to the use of neuroimaging in patients with migraine is necessary to balance the potential benefits of imaging with the potential risks and costs [ 1 ].

From the Research

Initial Migraine Imaging

The recommended initial imaging for migraine diagnosis is a topic of discussion among medical professionals.

• According to a study published in 2020 2, there is no necessity to do neuroimaging in patients with headaches consistent with migraine who have a normal neurologic examination, and there are no atypical features or red flags present.
• However, neuroimaging may be considered for presumed migraine for certain reasons, such as unusual, prolonged, or persistent aura; increasing frequency, severity, or change in clinical features; first or worst migraine; migraine with brainstem aura; migraine with confusion; migraine with motor manifestations (hemiplegic migraine); late-life migraine accompaniments; aura without headache; side-locked headache; and posttraumatic headache 2.
• A study published in 2002 3 found that computed tomography (CT) scan was normal in 61.5% of patients with migraine or tension-type headache, while a number of abnormalities were encountered in more than one third of the patients studied, including inflammatory sinus disease, cysticercosis, unruptured cerebral aneurysm, basilar impression, intracranial lipoma, arachnoid cyst, empty sella, intracranial neoplasm, and others.
• Another study published in 2010 4 found that the pre-test probability of significant intracranial abnormalities in persons with chronic headaches defined as headache experienced for at least a 4 week duration with a normal neurological exam was 0.9% (95% CI 0.5,1.4).

Imaging Modalities

• Computed tomography (CT) and magnetic resonance imaging (MRI) are two common imaging modalities used to evaluate patients with migraine.
• A study published in 2015 5 discussed the effectiveness of CT and MRI in the evaluation of a patient with a headache, as well as the utility and cost-effectiveness of performing imaging studies in patients with a headache and a normal neurological exam.
• MRI has been shown to be more sensitive than CT in detecting certain abnormalities, such as small foci of high intensity on T2-weighted and proton-density-weighted images in the white matter 6.

Clinical Considerations

• The decision to perform neuroimaging in patients with migraine should be based on individual clinical considerations, such as the presence of atypical features or red flags.
• A study published in 2020 2 recommended that neuroimaging may be considered for presumed migraine for certain reasons, such as unusual, prolonged, or persistent aura; increasing frequency, severity, or change in clinical features; first or worst migraine; migraine with brainstem aura; migraine with confusion; migraine with motor manifestations (hemiplegic migraine); late-life migraine accompaniments; aura without headache; side-locked headache; and posttraumatic headache.