Brain dysfunction underlying visual snow syndrome: Insights into therapeutic implications

Visual snow (VS) is defined as dynamic, continuous tiny dots across the entire visual field persisting for more than three months. VS is frequently associated with enhanced entoptic phenomenon, palinopsia, photophobia and night blindness. This constellation of symptoms is now referred to as visual snow syndrome (VSS). VSS is reported to affect approximately 2 % of the UK population. Neuroimaging has contributed to a better understanding of VSS disease mechanism. While the dysfunction of visual association area is likely to play a pivotal role in its pathophysiology, functional and microstructural abnormalities extend beyond the visual system. Nevertheless, no specific marker for VSS has been identified, which makes the diagnosis of VSS challenging. The treatment of VSS remains to be established. There has been only sporadic therapeutic success with lamotrigine and cognitive behavioral therapy. Given the complexity of its disease state, multidisciplinary therapeutic approaches appear to be required for more effective symptom management.