Abstract
In their recent report, Queiroz et al. (1) supplement their previous study on the characteristics of migraine visual aura (2). They confirm previous studies by stating that: the visual aura of migraine commonly lasts 5 to 30 minutes, has a gradual onset, usually begins peripherally, is unilateral, and shimmers. It is slightly more often without color, and is often described as small bright dots and zigzag lines (1).
They have also found that in some patients migraine visual aura may develop quickly, is short and may have multicoloured or rounded features. Nothing of this is new, as documented in numerous prospective and retrospective studies (cited by the authors), as well as illustrations of visual aura of migraine by patients (3).
My particular concern is that the authors isolate some features of migraine visual aura such as colour to question the differential criteria between the visual aura of migraine and visual occipital epileptic seizures. It should be remembered that: visual hallucinations of occipital seizures are entirely different from visual aura of migraine when individual elements of colour, shape, size, location, movement, speed of development, duration, and progress are synthesised together (4,5).
Elementary visual hallucinations of occipital seizures develop in seconds, usually last for 1–3 min, are mainly coloured and circular, commonly start unilaterally from the periphery moving towards the other side and may progress to other occipital seizure manifestations. No one of these elements in isolation, including colour, is sufficent to conclusively differentiate them from the visual aura of migraine for which they are often misdiagnosed exactly because some authors misunderstand the above basic principles of differential diagnosis.
It would be significant in this discussion to know if any of the 122 migraine patients of Queiroz et al. (1) had the clustering of features previously described (4,5), which appears to be characteristic of visual epileptic seizures and not of migraine. If yes, these cases should be clearly presented and analysed as truly challenging the differental criteria between the visual aura of migraine and visual epileptic seizures. Such cases should always raise the possibility of misdiagnosing epileptic seizures as migraine.