It is known that visual feedback and stimuli can trigger attacks of migraine headaches. This is assumed to occur due to the stimulation of a specific part of the brain called the visual cortex. Tinted corrected lenses have been examined in this study to check if their use can prevent attacks of migraine. Brain scans show that there is a normalization of the visual cortex activation when migraine sufferers wear corrected tinted lenses. The authors suggest that these may have a role in prevention of migraine.
Certain patterns such as stripes act as visual triggers that can start an attack of migraine in a prone individual. In epileptics, these have been known to start seizures or epileptic fits as well. Brain scans and functional magnetic resonance imaging (fMRI) scans have shown that special areas of the brain called the visual cortex are activated when these stimuli are provided; this activation may be responsible for the migraine attacks. Some studies have shown that color filters and tinted glasses may prevent this visual stimulation and reduce the discomfort in migraine sufferers. This study is the first in its attempt to check, by brain scan, the effects of the precision or corrected tinted glasses on the visual cortex and other areas of the brain in migraine sufferers.
- For this study, 11 migraine sufferers were chosen. For each of the participants, a gender- and age-matched healthy volunteer was also selected.
- All participants were asked to view migraine attack-inducing as well as non-stressful stripe patterns for the test. They viewed these with the help of gray, colored, or corrected tinted lenses.
- Simultaneous brain fMRI scans were also performed on all the participants.
- The results showed that all participants with all types of glasses had similar responses to the non-stressful stripes.
- On those other hand, when shown the migraine-triggering stripes, the migraine sufferers who wore colored or gray lenses had a pronounced activation of their visual cortex part of the brain. This was significantly more compared to those in the healthy volunteer group.
- It was noted that when the migraine sufferers wore precision tinted lenses, they experienced a normalization of their visual cortex activation to a large extent. These lenses also reduced visual discomfort better than both the other types of glasses in migraine sufferers.
The authors agree that the exact mechanism by which these striped patterns lead to visual stress is unknown. They admit that this mechanism of visual stress differs from the aversion to light, commonly termed photophobia, which occurs in migraine sufferers. They suggest further studies to explore these mechanisms in detail.
This study shows that when faced with a visually stressful pattern, migraine sufferers wearing gray or colored glasses show higher activation of the visual cortex of the brain when compared to healthy volunteers. This activation is normalized to a large extent if they view the striped patterns through corrected precision tinted lenses. The authors conclude that suppressing the activation of the visual cortex in the brain could prevent the continuous collective activation of the sites, which leads to a migraine attack. This activation of the cortex indicates that these stimuli may trigger an attack but the exact mechanism is not yet clear. These lenses could be used safely in the prevention of migraine attacks, due to their therapeutic effect in migraine sufferers who are prone to attacks when faced with a visually challenging pattern.
For More Information:
Brain Scan Evidence that Precision Tinted Lenses Reduce Visual Cortex Activation in Migraine
Publication Journal: Cephalalgia, May 2011
By Jie Huang; Xiaopeng Zong
From the Michigan State University, East Lansing, Michigan
*FYI Living Lab Reports Are Summaries of the Original Research.