If you live with photosensitive epilepsy, you are probably already aware of how light can impact you. But you may not realize that some types of static visual images can also trigger seizures in people with epilepsy and may even impact people with migraine, according to authors of a recent study.
More specifically, researchers noted how looking at these static patterns—typically some arrangement of vertical stripes—increased the intensity of a certain type of brain wave, called gamma oscillations. Even people without epileptic tendencies experience this type of neural activity, which can lead to feelings of discomfort. But it is especially influential in seizure provocation in photosensitive epilepsy. In fact, they acknowledged that stationary patterns can lead to seizures in about 30% of people with the condition, and they hypothesize it stems from gamma oscillations.1
Why do static, vertical stripe patterns cause problems?
It may be understandable that the flickering or movement of light could overstimulate the brain, but how do static patterns produce these results?
Some researchers have hypothesized that our brains are just not comfortable with extreme stripe patterns because they are not found in the natural world. Stripes in nature, such as on animals like zebras, are not perfectly uniform. When we encounter a perfect striped pattern -- especially with high contrast—our brains simply do not know exactly how to process the visual input. So whether you're healthy or have a neurological deficit, your brain distrusts the information.
Why are people with migraine also vulnerable?
It’s important to note that this new research does not specifically address migraine. However, we already know that harsh light and visual patterns can bring on attacks, and other studies have found connections between migraine attacks and gamma oscillations. In one study, children in the middle of a migraine attack had high gamma oscillations as well as other abnormal brain activity.2 Another analysis showed that striped patterns specifically yielded dysfunction in the visual cortex of patients—which is also associated with gamma oscillations—and they reported visual distortions that, in some cases, mimicked the illusion of movement. As a result, they were more likely to experience discomfort or even the onset of a migraine attack after looking at them for a sustained period of time.3
Is it possible to minimize the impact of vertical stripe patterns?
With the prevalence of these patterns in society—from crosswalks on the streets to window blinds in your home—it is important to find ways to minimize their impact on your health. If you have control over your exposure to these visuals, researchers suggest:
- blurring the edges of the lines
- avoiding sharp contrast designs
- making the stripes vary in size
- creating slightly wavy lines
- overlaying perpendicular lines to create a checkerboard pattern
If you do not have direct control over the type of pattern, then avoiding or covering them may be your best option. In addition, precision tinted lenses may be an effective solution for helping reduce the hyperreactivity that occurs upon viewing these types of images. These simple changes helps the brain interpret visual information without such a strong reaction.
1 Hermes D, Kasteleijn-Nolst Trenite D.G.A, Winawer J. Gamma oscillations and photosensitive epilepsy. Current Biology. 2017; 27(9); doi: 10.1016/j.cub.2017.03.076.
2 Guo X, Xiang J, Wang Y, et al. Aberrant Neuromagnetic Activation in the Motor Cortex in Children with Acute Migraine: A Magnetoencephalography Study. Paul F, ed. PLoS ONE. 2012;7(11):e50095. doi:10.1371/journal.pone.0050095.
3 Huang J, Zong X, Wilkins A, Jenkins B, Bozoki A, Cao Y. fMRI evidence that precision ophthalmic tints reduce cortical hyperactivation in migraine. Cephalalgia : an international journal of headache. 2011;31(8):925-936. doi:10.1177/0333102411409076.