The spectrum of migraine aura: Towards a precise phenotypic classification

IntroductionTypical migraine aura is characterized by transient focal neurologic symptoms, visual, sensory, dysphasic or other higher cortical dysfunctions. Their manifestations are multi-faceted, with inter and intra-variability.ObjectiveTo provide a narrative review describing contributions that assist in achieving a precise phenotypic classification of migraine aura.MethodsWe conducted a comprehensive review of the literature to identify and analyze the full spectrum of migraine aura variables. Based on the findings, we proposed a prospective diary model for systematically recording these elements in clinical or research settings.ResultsVisual symptoms are the most multifaceted with many peculiarities such as quality (26 elementary visual symptoms have been described), colour, intermittence, localization and laterality in visual field and direction of spreading. Sensory and dysphasic symptoms have lower level of complexity. The combinations of symptoms, such as their time relationships or duration, are also extremely variable. Furthermore, headache can have five different patterns of presentation with respect to aura onset/end. Higher cortical dysfunctions need to be further investigated in wider populations. After collecting the full spectrum of migraine aura features, we created a diary which we propose can prospectively record those variables.ConclusionThe findings of this review show that migraine auras present a wide and multi-faceted spectrum of symptoms, generating hundreds of possible scenarios. Therefore, a detailed aura diary to complete during attacks will be of utmost importance to move toward a precise phenotypic classification.