NEUROSCIENCE: Edited by Marek A. MirskiClinical presentation of autoimmune and viral encephalitidesDubey, Divyanshua,b; Toledano, Michela; McKeon, Andrewa,bAuthor Information aDepartment of Neurology bDepartment of Laboratory Medicine, Mayo Clinic, Rochester, Minnesota, USA Correspondence to Divyanshu Dubey, MD, Neuroimmunology Laboratory, Mayo Clinic, 200 1st ST SW, Rochester, MN, 55905, USA. Tel: +1 507 266 3196; fax: +1 507 538 7060; e-mail: email@example.com Current Opinion in Critical Care: April 2018 - Volume 24 - Issue 2 - p 80-90 doi: 10.1097/MCC.0000000000000483 Buy Metrics Abstract Purpose of review We describe clinical and diagnostic features of various autoimmune and viral encephalitis subtypes. Recent findings Population-based studies have demonstrated both autoimmune and viral causes have similar prevalence and incident rates. Repertoire of autoimmune biomarkers has considerably increased with discovery of many novel neural antibodies including glial fibrillary acidic proteinα-immunoglobulin G. Similarly, with use of next generation sequencing and DNA libraries, many viral causes are being detected which would have been categorized as encephalitis of unknown cause a decade ago. Summary Autoimmune and viral encephalitides can resemble one another and sometimes autoimmune encephalitis may be triggered by viral infections. Early diagnosis and treatment is the key to both causes, which emphasizes the importance of clinical diagnosis before laboratory confirmation. Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved.