Visual snow syndrome (VSS) has long been recognized as a constellation of symptoms in the absence of signs but has either been attributed to untreatable migraine or psychogenic causes. This dichotomy has caused incredible stress for afflicted individuals who felt dismissed. In 1995 however, for the first time, it was recognized as a clinicopathological entity on its own, separable from other disorders. The definition was further refined over the first decade of this century, and finally recognized as an entity in the International Headache Classification, but as a “rare” entity. More recent information indicates that it may affect as many as 2-4% of the community. Significant progress has been made in demonstrating that this is a physiologically aberrant function, but much still remains to be done.
Recent investigations with functional imaging, psychophysical evaluations of visual perception, and physiological studies of central processing in visual, integrated sensorimotor systems, have demonstrated both structure-related functional abnormalities (fMRI) and a neurophysiological signature for this disorder that differentiates it from migraine and proves it is not “psychogenic”. We still do not understand the locus of pathology nor the mechanism of dysfunction. Moreover, although the syndrome itself is tightly defined, there are a large number of associated disturbances, generally classified as being within other sensory domains e.g. auditory, vestibular, and peripheral sensory perceptions such as paraesthesia. Symptoms such as depersonalization and derealization may be classified as afferent/efferent mismatch of perception of person. Finally, there appear to be several triggers reported by individual patients. Certainly, hallucinogens seem associated with a very similar disruptive process. Whether such drugs cause the disorder or uncover an underlying predisposition is unknown at this stage.
Areas of interest include, but are not limited to the following:
• Localization through structural and functional analysis
• Pathophysiological clarification of VSS
• Analysis of individual symptoms such as nyctalopia, photophobia, and palinopsia
• Analysis of the associated features such as depersonalization, derealization
• Elucidation of associated syndromes such as persistent perceptual postural dizziness, hallucinogen persisting perceptual disorder, persistent migratory paraesthesia, and others
• Analysis of case series and widening of understanding of fundamental abnormalities
We seek original research papers, case series, and review articles of symptomatology and associated syndromes more so than the global syndrome.
We acknowledge the funding of the manuscripts submitted to this Research Topic by the Not-for-Profit Corporation, Visual Snow Initiative. We hereby state publicly that Visual Snow Initiative has had no editorial input in articles included in this Research Topic, thus ensuring that all aspects of this Research Topic are evaluated objectively, unbiased by any specific policy or opinion of Visual Snow Initiative.
Visual snow syndrome (VSS) has long been recognized as a constellation of symptoms in the absence of signs but has either been attributed to untreatable migraine or psychogenic causes. This dichotomy has caused incredible stress for afflicted individuals who felt dismissed. In 1995 however, for the first time, it was recognized as a clinicopathological entity on its own, separable from other disorders. The definition was further refined over the first decade of this century, and finally recognized as an entity in the International Headache Classification, but as a “rare” entity. More recent information indicates that it may affect as many as 2-4% of the community. Significant progress has been made in demonstrating that this is a physiologically aberrant function, but much still remains to be done.
Recent investigations with functional imaging, psychophysical evaluations of visual perception, and physiological studies of central processing in visual, integrated sensorimotor systems, have demonstrated both structure-related functional abnormalities (fMRI) and a neurophysiological signature for this disorder that differentiates it from migraine and proves it is not “psychogenic”. We still do not understand the locus of pathology nor the mechanism of dysfunction. Moreover, although the syndrome itself is tightly defined, there are a large number of associated disturbances, generally classified as being within other sensory domains e.g. auditory, vestibular, and peripheral sensory perceptions such as paraesthesia. Symptoms such as depersonalization and derealization may be classified as afferent/efferent mismatch of perception of person. Finally, there appear to be several triggers reported by individual patients. Certainly, hallucinogens seem associated with a very similar disruptive process. Whether such drugs cause the disorder or uncover an underlying predisposition is unknown at this stage.
Areas of interest include, but are not limited to the following:
• Localization through structural and functional analysis
• Pathophysiological clarification of VSS
• Analysis of individual symptoms such as nyctalopia, photophobia, and palinopsia
• Analysis of the associated features such as depersonalization, derealization
• Elucidation of associated syndromes such as persistent perceptual postural dizziness, hallucinogen persisting perceptual disorder, persistent migratory paraesthesia, and others
• Analysis of case series and widening of understanding of fundamental abnormalities
We seek original research papers, case series, and review articles of symptomatology and associated syndromes more so than the global syndrome.
We acknowledge the funding of the manuscripts submitted to this Research Topic by the Not-for-Profit Corporation, Visual Snow Initiative. We hereby state publicly that Visual Snow Initiative has had no editorial input in articles included in this Research Topic, thus ensuring that all aspects of this Research Topic are evaluated objectively, unbiased by any specific policy or opinion of Visual Snow Initiative.
