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Visual Snow Syndrome as a Network Disorder: A Systematic Review
Antonia Klein1, Christoph J Schankin1
1Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
Frontiers in Neurology
|October 21, 2021
Summary
Visual snow syndrome (VSS) is a complex network disorder affecting visual and extra-visual brain areas. Research indicates disruptions in large-scale brain networks, impacting visual processing and attention.
Area of Science:
- Neuroscience
- Ophthalmology
- Neurology
Background:
- Visual snow syndrome (VSS) presents with persistent visual disturbances resembling static, impacting quality of life.
- The exact prevalence of VSS is unknown, but it may affect up to 2.2% of the population.
- Current understanding of VSS pathophysiology and effective treatments remains limited.
Approach:
- A systematic review of clinical and paraclinical studies on visual snow (VS) and VSS was conducted.
- Studies were identified through searches of PubMed and Google Scholar using the term "visual snow."
- Included studies were original research in English or German, excluding reviews and non-retrievable articles.
Key Points:
- VSS encompasses a spectrum of visual disturbances (e.g., floaters, photophobia) and is associated with perceptual, affective, and cognitive symptoms.
- Studies reveal structural, functional, and metabolic alterations in visual cortex and pre-cortical pathways.
- Disruptions in large-scale brain networks, including the default mode and salience networks, are implicated in VSS.
Conclusions:
- The clinical presentation and widespread brain alterations strongly suggest VSS is a network disorder.
- Impaired filtering and prioritization of stimuli due to pre-cortical and attentional network involvement may lead to overactivation of visual cortices.
- Further research is needed to standardize VSS definitions and improve control group matching in studies.
Keywords:
electrophysiologyimagingnetwork disorderneuroophtalmologyperceptual disordersystematic (literature) reviewvisual disturbancevisual snow syndromeMore Related Videos
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