The frequency of the 'visual snow' phenomenon in patients with migraine

Abstract

Introduction: "Visual Snow" phenomenon represents visual disturbances, which consist of small, dynamic, flickering dots present in both eyes, in the entire visual field, like the interference of static electricity, so-called "snow" on the old, analog TVs. Symptoms occur constantly and can last for years. Objective parameters so that this phenomenon can be measured do not exist at the moment, so these people are often diagnosed simulation, psychiatric disorders or persistent migraine aura. Aim: To assess the prevalence of the "visual snow" phenomenon in patients with migraine without aura, migraine with aura, and for people who do not have migraines. Materials and Methods:This cross-sectional study included 150 subjects of both genders, ages 18 to 60 years. Subjects were classified into 3 groups. The first group consisted of 50 patients with migraine with aura (MA), the other 50 patients with migraine without aura (MO), and the third 50 healthy subjects (ZK). The research was conducted with the interview, respondents were given 6 photos with signs characteristic of "visual snow" syndrome. These groups were compared with each other by age, gender and the presence of visual symptoms characteristic of the "visual snow" syndrome. Results: The frequency of "visual snow" phenomenon did not differ significantly in compared groups (8% vs. 6% vs. 6%). Additional visual symptoms were significantly more frequent in groups MA and MO compared to the ZK, "visual snow" in the dark (38% vs.32% vs. 14%), the presence of spots in the visual field (48% vs. 24% vs. 2%), the presence of "blue field" entoptic phenomenon (20% vs. 10% vs. 4%), "after image" of steady (18% vs. 16% vs. 0%) and movable object (12% vs. 10% vs. 2%). Additional visual symptoms were significantly more common in people with migraine, especially MA, compared to healthy subjects (68% vs. 54% vs. 22%). Conclusion: "Visual snow" phenomenon occurs in about 7 % of people, equally often in those with migraine and without migraine. Other visual symptoms, such as "visual snow" in the dark, palinopsia and entoptic phenomena, occur more frequently in patients with migraine (with and without aura), compared to people without migraines. Further studies are needed to understand the connection between these phenomena in the pathophysiology of migraine.