Perfusion Computed Tomography Effective for Differentiating Migrainous Aura From Stroke

Perfusion computed tomography (PCT) offers greater accuracy in diagnosing migrainous aura (MA) and differentiating symptoms from those present in stroke when compared with brain non-contrast computed tomography (NCCT) and CT angiography (CTA) in patients presenting with acute onset of neurological symptoms, according to study findings published in Clinical Neurology and Neurosurgery.

Investigators of this study compared perfusion patterns on PCT of patients with MA (n=6) with perfusion patterns of patients with acute ischemic stroke (n=172).  General and neurological examinations were performed using urgent hematological tests and the National Institutes of Health Stroke Scale and all patients underwent NCCT, CTA, and PCT.

Brain CT, CT angiography, and PCT were performed approximately 60-90 minutes following the onset of MA symptoms. Acute lesions or vascular disease were not found in either brain CT or CT angiography groups. Qualitative and quantitative patterns that were compatible with normal perfusion were demonstrated in all 6 patients, and PCT also demonstrated a symmetric perfusion that had higher cerebral blood volume and cerebral blood flow in gray matter vs white matter. Results of the brain-CT scan, specifically for cerebrovascular disease, were normal in all patients.

Based on these results, the study researchers concluded that normal perfusion neuroimaging may suggest MA and that PCT may be a useful tool in the diagnostic algorithm when clinicians are working up causes of acute neurological deficits.

This study was comprised of only 6 patients, which limits the power of the findings and prevents generalizability across a wider MA patient population. In addition, the findings of this imaging study were obtained retrospectively, further limiting the results.

The use of “PCT may add confidence in detecting a potentially treatable stroke, but, when negative, it may lead the clinicians to consider the occurrence of a stroke mimics” while avoiding the use of unnecessary reperfusion therapies.

Reference

Ridolfi M, Granato A, Polverino P, et al. Migrainous aura as stroke-mimic: The role of perfusion-computed tomography. Clin Neurol Neurosurg. 2018;166:131-135