This page contains links to useful resources that relate to Visual Snow Syndrome, including support groups, media coverage, websites, videos and research publications.
Visual Snow Conference This one day conference provides a great opportunity for patients, their families, and the medical community to discuss the condition and build our understanding. Key speakers include researchers at the forefront of VS research. You have to register but it’s completely free. Check out the website for more details.
See also the three news videos below.
Visual snow syndrome | Genetic and Rare Diseases Information Centre (GARD) GARD is a program of the National Center for Advancing Translational Sciences (NCATS) to provide access to current, reliable, and easy to understand information about rare or genetic diseases. Their visual snow webpage is informative and well-referenced.
Eye On Vision Foundation The Eye On Vision Foundation is an American charity supporting and funding research into Visual Snow Syndrome. Donate here!
Help Cure Visual Snow by Jen Ambrose | GoFundMe This is the GoFundMe fundraiser set up by Jen Ambrose/the Eye On Vision Foundation. You can donate through this site, but it is preferable to donate to the Eye On Vision Foundation directly, as GoFundMe take a cut of any donations made. The page contains a good explanation of VS and its impact.
Visual Snow Awareness Contains lots of submissions about people’s experiences with Visual Snow Syndrome. My favourite post is by Adam at the bottom of the page; the last paragraph reads: ‘It’s a life ruining eye condition that I have been stuck with, but I’ll be damned if I let it define me. It will never keep me from work, college, or pursuing any passions I have. I am the master of my eyes.’
C Schankin et al, ‘Visual snow’ – a disorder distinct from persistent migraine aura (2014) In-depth research (using questionnaires and interviews) into patients suffering from Visual Snow Syndrome, and establishes that the condition is a real and unique syndrome. It proposes diagnostic criteria for VS and explains what the core symptoms are and their prevalence. If you are interested in reading the research into VS, this would be the best starting place.
C Schankin et al, Clinical characterization of “visual snow” (Positive Persistent Visual Disturbance) (2012) A poster presentation of earlier research conducted by Schankin et al that feeds into the above 2014 study.
H Jäger, N Giffin and P Goadsby, Diffusion- and perfusion-weighted MR imaging in persistent migrainous visual disturbances (2004) Finds that changes in how the water flows through the brain are not responsible for Visual Snow Syndrome; this was significant as it has been shown that changes in water diffusion and perfusion in the brain are linked to migraine. Therefore, they suggested for the first time that VS should be treated separately from migraine with persistent aura.
C Schankin et al, ‘The Relation Between Migraine, Typical Migraine Aura and Visual Snow’ (2015) Shows that Visual Snow Syndrome patients who also suffer from migraines have a greater likelihood of suffering from palinopsia, spontaneous photopsia, photophobia, nyctalopia and tinnitus. Therefore, they conclude that migraine aggravates VS symptoms. Additionally, they found that typical migraine aura does not impact VS symptoms, and since it is a common problem alongside the Syndrome, they conclude that the conditions may share pathophysiology (i.e. they may be caused by the same physical processes in the brain). Using PET scans, they also found that there was hypermetabolism in the right lingual gyrus and left cerebellar anterior lobe in the brains of VS patients. This is significant as it is the first objective finding in VS (i.e. we can see that there is actually something wrong!). Notably, the same parts of the brain have more blood moving through them during light sensitivity during a migraine, confirming overlap between migraine and VS. They also suggest that tinnitus, given how prevalent it is, may be another core symptom of Visual Snow Syndrome.
C Schankin and P Goadsby, Visual Snow—Persistent Positive Visual Phenomenon Distinct from Migraine Aura (2015) Explains how Visual Snow Syndrome behaves differently to persistent migraine aura, both in how the symptoms present themselves (VS affects the vision in a uniform manner, whereas migraine is homonymous) and the electrophysiological activity in the brain. They then review previous literature, explain what the symptoms of VS are and how it relates to migraine and typical migraine aura. In general, it gives a good overview of what Visual Snow Syndrome is and the important research that has been done into it – another good read!
R Kaniecki, F Taylor, and S Landy, Abstracts and Citations (2014) Only the first page or so is relevant, but it includes some brief thoughts from three reputable neurologists on Schankin et al’s 2014 study, as well as some suggested further reading.
J Simpson, P Goadsby and P Prabhakar, Positive Persistent Visual Symptoms (Visual Snow) Presenting as a Migraine Variant in a 12-Year-Old Girl (2001) A case report about a 12-year-old girl who appeared to have Visual Snow Syndrome. It reflects the experience of many sufferers no abnormal results from any neurological, physical or psychological tests, and no response to various therapies. It also includes an interesting drawing produced by the 12-year-old illustrating her symptoms. It shows how even young children can be affected, and it illustrates clearly the high impact on quality of life.
J Lauschke et al., Visual snow A thalamocortical dysrhythmia of the visual pathway (2015) Reviews the symptoms of 32 patients with Visual Snow Syndrome. Notably, it highlights the prevalence of tremor in VS patients, a symptom rarely mentioned in relation to the condition. They explore how colour filters can reduce the severity of VS symptoms, particularly filters that are in the yellow-blue spectrum. Since VS is associated with tinnitus, tremor, migraine, and palinopsia, and is related to colour-dependant processing (evidence by the impact that coloured filters have on symptoms), they conclude that VS may be the result of an imbalance of koniocellular and magnocellular pathway function creating a thalamocortical dysrhythmia that results in a disorder of visual processing. Unfortunately, the paper does not explain what this means. However, the koniocellular and magnocellular pathways are two distinct visual pathways carrying information from the retina to the brain. The koniocellular pathway is responsible for high-definition visual perception, and helps you identify shapes. The magnocellular pathway is less high-definition, and helps you perceive motion. The study is essentially saying that there is an imbalance between these two pathways, which disturbs key signals that travel between the thalamus and the cortex in the brain, leading to VS symptoms. It is difficult to understand, but to read more about thalamocortical dysrhythmia, click here.
A Bessero and G Plant, Should ‘visual snow’ and persistence of after-images be recognised as a new visual syndrome (2014) A short article, similar to Schankin et al (2014), that investigates the symptoms of 27 patients and concludes that Visual Snow Syndrome should be treated as a new visual syndrome that is distinct from persistent migraine aura and HPPD.
I Cevik and F Yildiz, Visual Snow in Migraine With Aura Further Characterization by Brain Imaging, Electrophysiology, and Treatment – Case Report (2015) A case report of a woman who had visual snow for a year, migraine aura for 10 years, occipital bending (i.e. where the occipital lobes at the back of the brain twist around each other) and cortical hyperexcitability. Her symptoms improved after giving her Lamotrigine (an anti-convulsant). This appears to be a case of persistent migraine aura, but given the overlap between VS and migraine, the study is relevant to Visual Snow Syndrome.
A Ghannam and V Pelak, Visual Snow: a Potential Cortical Hyperexcitability Syndrome (2017) Reviews the literature regarding what Visual Snow Syndrome is and outlines potential treatment options. They recognise that the main theory to explain Visual Snow is neuronal cortical hyperexcitability, though the exact mechanism for this is yet to be established. Until research establishes this, it is difficult to resolve VS with treatment. Nonetheless, their experience suggests that lamotrigine, acetazolamide and verapamil can help reduce (though not eliminate) symptoms to improve patient’s quality of life to some extent. They recommend that these medications should be investigated further in clinical trials. They are of the opinion ‘that new treatment approaches and treatment trials will emerge in the next decade.’
C Schankin et al, Persistent and Repetitive Visual Disturbances in Migraine: A Review (2016) Reviews and describes previous studies and literature regarding migraines generally as well as Visual Snow Syndrome. Notably, its expands upon the potential role of the lingual gyrus by suggesting that it is important in adjusting the brightness of light perception. It proposes that healthy subjects have an active system in the visual cortex which suppresses the symptoms experienced by VS patients – the lingual gyrus is thought to be key in this system. It is believed that since the lingual gyrus is overactive in VS patients, the suppression system malfunctions and fails to subdue VS symptoms. It also notes how in previous studies treatments, which can be useful in reducing migraine symptoms, are often ineffective for VS patients but are worth trying following a diagnosis. It suggests that Verapamil, a treatment for certain types of migraine, may be prescribed when other medicines fail.