Visual snow

Abstract

Visual snow is characterized by continuous visual disturbances in the form of countless tiny particles present in the entire visual field, often interpreted as television static. The visual disturbances are almost always accompanied by additional symptoms, including palinopsia, nyctalopia, photophobia, entoptic phenomenon, bilateral tinnitus, concentration problems, lethargy, and irritability. Visual snow has been linked to migraine and the migrainous aura. The clinical phenotype of visual snow clearly different from migraine; however, the co-occurrence with migraine (aura) might imply that both conditions share underlying pathophysiological mechanism(s). Visual snow is currently diagnosed on patient history alone, as additional investigations are typical normal and do not contribute to the diagnosis. However, ophthalmological investigation, neuroimaging, and, in selected cases, electroencephalography are recommend to rule out other disorders. Although self-limiting in some cases, visual snow typically remains a chronic condition that is very difficult to suppress with drug or non-pharmacological treatment.