Visual snow: Not so benign

Visual snow is the perception of flickering dots throughout the entire visual field and occurs with other symptoms of dysfunctional central sensory processing. We describe a patient who presented with visual snow, illusory visual motion, photopsia, and reduced night vision. He subsequently developed progressive cognitive impairment, myoclonus and ataxia. A diagnosis of sporadic Creutzfeldt-Jakob Disease was confirmed on post-mortem examination more than 49 months after symptom onset. The visual snow syndrome is typically benign, but our patient illustrates that occasionally it is the first manifestation of a serious brain disease. Careful application of the diagnostic criteria for the visual snow syndrome is important, particularly with the use of neuroimaging to exclude pathology in the occipital cortex. (C) 2019 Elsevier Ltd. All rights reserved.