New research, published recently in Headache, is giving new insight into the experiences associated with visual aura and how they differ for people with migraine and epilepsy. These are some of the key findings from the study.
Visual auras last longer for migraine patients
People with migraine often describe a slow onset of visual symptoms prior to the headache phase of a migraine attack—sensations that can take several minutes to fully manifest and last just as long. In this latest analysis, the average duration of the aura was 20 minutes, with the majority lasting between 10 to 30 minutes, which is consistent with previous research. Conversely, epileptic individuals had much shorter visual disruptions, with most lasting between 30 seconds and 2 minutes. Researchers also reported that the onset of auras with an epileptic origin was much quicker.
Epileptic auras consistently affect one side
Another noteworthy difference had to do with the “lateralization” of the auras, which refers to how the disturbances affect all or part of the field of vision. Among those with epileptic aura, symptoms were generally restricted to one side of their visual field. In fact, 74% of patients cited that they experienced this particular sensation. In addition, the aura consistently affected the same side from episode to episode. Those in the migraine group, on the other hand, were much less likely to experience auras that only impacted a portion of their vision (30%)—and even then, it was variable between attacks.
Generally, there was not much difference in the type of symptoms observed by patients with either migraine or epilepsy auras. Both could be characterized by white spots or rings as well as negative visual symptoms such as tunnel vision or blind spots. The one notable divergence related to the spreading of the disturbance across the visual field, which occurred for one out of every three migraineurs.
Nausea and photophobia are hallmarks of migraine aura
More than 63% of people with migraine reported painful light sensitivity (photophobia) and nausea or vomiting as accompanying symptoms of their visual auras. In addition, head pain was much more likely to occur immediately following the aura, making it a clear marker for migraine. In contrast, epilepsy patients were more likely to have other sensory disruptions—such as abdominal, auditory or otherwise involving the head (e.g. dull feeling or tingling). These sensations also rarely lasted more than a few minutes and were not necessarily followed by seizures.
What does it mean for patients?
The most important aspect of this study revolves around the further differentiation between aura symptoms of specific neurological conditions. Researchers believe the clinical characteristics described herein (as well as those of future studies) can be diagnostic reference points for medical professionals who treat patients with visual symptoms that do not present a clear underlying cause.
Hartl, E., Angel, J., Rémi, J., Schankin, C. J. and Noachtar, S. (2017), Visual Auras in Epilepsy and Migraine – An Analysis of Clinical Characteristics. Headache: The Journal of Head and Face Pain, 57: 908–916. doi:10.1111/head.13113
Queiroz, L. P., Rapoport, A. M., Weeks, R. E., Sheftell, F. D., Siegel, S. E. and Baskin, S. M. (1997), Characteristics of Migraine Visual Aura. Headache: The Journal of Head and Face Pain, 37: 137–141. doi:10.1046/j.1526-4610.1997.3703137.x
Queiroz LP, Friedman DI, Rapoport AM, Purdy RA. Characteristics of migraine visual aura in Southern Brazil and Northern USA. Cephalalgia. 2011 Dec;31(16):1652-8. doi: 10.1177/0333102411430263. Epub 2011 Nov 24.
Liu Y, Guo X-M, Wu X, Li P, Wang W-W. Clinical Analysis of Partial Epilepsy with Auras. Chinese Medical Journal. 2017;130(3):318-322. doi:10.4103/0366-6999.198918.