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The guidelines included a review of 23 studies, suggesting that patients with normal neurological examinations do not require neuroimaging assessments as part of migraine treatment.
Randolph W. Evans, MD
The American Headache Society (AHS) has published new neuroimaging guidelines for the care of patients with migraine, suggesting that in those with normal neurologic examination without atypical features or red flags, there is no need for neuroimaging.
The review, conducted by a group of authors including Randolph W. Evans, MD, clinical professor of neurology, Baylor College of Medicine, consisted of 23 articles that attempted to evaluate neuroimaging in migraine.
“There is no evidence that routine imaging for migraine meeting International Classification of Headache Disorders 3rd edition criteria is more likely to reveal meaningful abnormalities compared to the general healthy population in the absence of worrisome features,” Evans and colleagues wrote. “Several studies affirm that routine neuroimaging for migraine meeting the criteria is more likely to identify incidental abnormalities than identify serious problems, potentially creating anxiety or leading to further work‐up.”
Notably, this review did not assess the emerging neuroimaging research into functional neuroimaging, or those studies used to investigate secondary headache disorders such as cerebrospinal fluid flow studies, or MRI venograms to evaluate for transverse sinus stenosis.
"I believe these new guidelines support current practice in that Migraine is a diagnosis based on clinical symptoms in a setting of normal Neurological exam. Having guidelines that support this just allows us to continue to practice the way we have been and provide some comfort that data supports what we do," Jessica Ailani, MD, FAHS, director, MedStar Georgetown Headache Center, and associate professor of neurology, MedStar Georgetown University Hospital, told NeurologyLive. "I do believe there are times we need to consider imaging, and having Grade A recommendations to image a patient in specific conditions (for example, unusual aura, late in life migraine, change in symptoms), again supports what we do clinically with evidence."
The group identified a number of reasons for which neuroimaging may be considered for migraine, including the following: 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.
“Reducing the overutilization of neuroimaging is a high priority as we move toward value‐based care delivery models,” Evans et al detailed. “In many cases, clinicians may overestimate the patient's desire to receive neuroimaging. The threshold to perform neuroimaging varies considerably from provider to provider, even among specialists.”
Evans and colleagues began the work with 2269 publications, which was narrowed to 85 articles and finalized to 23 which met inclusion criteria. The majority of studies were retrospective cohort or cross‐sectional studies, and 4 prospective observational studies.
They wrote that while sometimes the justification for neuroimaging is to relieve the anxiety of patients, studies suggest that this anxiety often is reduced within the first year of treatment for many patients. Although, as it can reduce costs for those with elevated psychiatric co‐morbidity, the group recommended establishing strong relationships with and education of patients about the low yield of neuroimaging as an alternative.
Additionally, reevaluating patients is necessary in light of changes in disease characterization or resistance to medication. Patients, Evans et al. recommend, should be reassured that neuroimaging can be performed later if new symptoms develop.
“Patients with potential warning signs of catastrophic headache (e.g., thunderclap headache, neurologic deficits) in need of urgent attention rarely present in an outpatient setting and are an exception,” they wrote.
Of the 23 articles, 18 focused on the use of neuroimaging in the setting of a normal neurological exam and diagnosis of migraine, while the other 5 focused on migraine subjects with more worrisome signs or symptoms raising concern for a secondary cause. As far as neuroimaging methods, 10 studies assessed CT scan results, 9 evaluated the results of MRI, and 4 included subjects who had undergone either MRI or CT.
The CT studies found mixed results due to varying study parameters, with the percentage of patients with abnormalities ranging from 0.002% to 47.1%. The MRI studies showed that 16% (30 of 185 patients) had white matter abnormalities, with a higher prevalence in subjects older than 50 and those with risk factors such as hypertension, heart disease, or diabetes. In the 4 studies with either CT or MRI, 0% (0 of the 382 subjects) undergoing CT had significant abnormalities, while 0.67% (3 of 688 subjects) 3 of the migraine subjects had imaging abnormalities receiving MRI.
Evans RW, Burch RC, Frishberg BM, et al. Neuroimaging for Migraine: The American Headache Society Systematic Review and Evidence‐Based Guideline. Headache. Published December 31, 2019. doi: 10.1111/head.13720.