Neuropsychiatric Disease and Treatment (Nov 2021)
Not All Cases of Visual Snows are Benign: Mimics of Visual Snow Syndrome
Abstract
Chenyue Hang,1 Lakshmi Leishangthem,2 Yan Yan3 1Ottawa-Shanghai Joint School of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China; 2Department of Neurology and Ophthalmology, University of Connecticut, Farmington, CT, USA; 3Department of Ophthalmology, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of ChinaCorrespondence: Yan YanDepartment of Ophthalmology, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Pujian Road 160, Shanghai, People’s Republic of ChinaTel +86 21 58752345Email [email protected]: Visual snow syndrome (VSS) is a clinical disorder characterized by pan-field visual disturbance. It is a diagnosis of exclusion since its pathophysiology remains unknown. Excluding other mimics is of great significance since some serious pathologies can have secondary visual snow (VS) as an initial presentation. Delayed or incorrect diagnosis of these VSS mimics may lead to permanent vision loss or even death. The purpose of this review is to help physicians distinguish VSS mimics promptly to avoid bad outcomes. The authors performed a PubMed literature search of articles, case reports, and reviews describing VS symptoms in patients with underlying diseases other than VSS. The red flags of secondary VS symptoms were highlighted, such as new-onset or intermittent VS, unilateral or quadrant VS, and accompanied ocular or neurological deficits. There are four main categories of VSS mimics, ie, including neurological disorders, ocular pathologies, drug-related VS, and other systemic diseases. The physicians could largely exclude most etiologies based on history taking, ophthalmologic and neurologic examinations, and neuroimaging. Further research in VS should carefully define and unify the inclusion and exclusion criteria of this disorder and investigate these secondary VS conditions and their pathogenesis.Keywords: birdshot chorioretinopathy, Creutzfeldt–Jakob disease, hallucinogen persisting perception disorder, migraine with visual aura, visual snow
