[Characterization of a German cohort with visual snow syndrome].

Background: Visual snow is a disorder of visual perception that is manifested as a constant flickering or "TV-like" noise in the entire visual field. Visual snow syndrome (VSS) describes a combination with other additional visual symptoms, such as sensitivity to light, afterimages, night blindness and entoptic phenomena. Cases of VS have been described in the literature using a wide variety of terms, often misunderstood as persistent migraine aura. Established diagnostic criteria have existed for more than 10 years now; however, the pathophysiology is still incompletely understood. The exact prevalence also remains unknown and high numbers of unreported cases are suspected. This is the first detailed description of a cohort of VSS patients from Germany.

Methods: Patients with VSS from several studies conducted at our center were pooled and retrospectively evaluated with respect to demographic, epidemiological and clinical data.

Results: In this study 66 patients with VSS were included (age 31.3 ± 8.3 years, 30 women). The most commonly associated visual symptoms were photophobia (67%) and afterimages (65%). Of the patients 36 (54%) had comorbid migraine of whom 25 (70%) had migraine with aura, 26 (39%) reported depressive symptoms and 32 (48%) symptoms of an anxiety disorder. Tinnitus was reported by 32 (48%) patients.

Conclusion: The characteristics of the German cohort described here are similar to other international descriptions. Due to the frequent psychological comorbidity there is still a risk of psychosomatic stigmatization.