Brief ReportsWest Nile Virus Neuroinvasive Disease Accelerating Probable Dementia With Lewy BodiesSegers, Kurt MD*; Van Ranst, Alexander MD*; Bostan, Alionka PhD*; Glibert, Gerald MD*; Maillart, Evelyne MD†; Clevenbergh, Philippe PhD†; Dachy, Bernard MD*Author Information Departments of *Neurology †Infectious Diseases, Brugmann Hospital, Brussels, Belgium The authors declare no conflicts of interest. Reprints: Kurt Segers, MD, Department of Neurology, Brugmann Hospital, Van Gehuchtenplein 4, Brussels 1020, Belgium (e-mail: [email protected]). Alzheimer Disease & Associated Disorders: July-September 2021 - Volume 35 - Issue 3 - p 269-270 doi: 10.1097/WAD.0000000000000405 Buy Metrics Abstract We describe a case of dementia with Lewy bodies immediately following encephalitis due to West Nile virus (WNV). The patient had rapid eye movement–sleep behavior disorder and constipation before the onset of encephalitis, which suggests that he would have ultimately developed dementia with Lewy bodies even without WNV infection. Our case illustrates the interactions between α-synuclein and WNV, as observed in mouse models, wherein synuclein expression augments after WNV infection and protects neurons against the virus. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.