Seizures and encephalitis: clinical features, management, and potential pathophysiologic mechanisms

Encephalitis is an inflammation and swelling of the brain, which is often caused by a viral infection; it is an important cause of acute symptomatic seizures as well as subsequent epilepsy. Herein we describe the definition, epidemiology, and etiology of encephalitis as a cause of seizures. We then focus on encephalitis due to herpes simplex virus (the most common sporadic viral cause of encephalitis) and Japanese encephalitis virus (the most common epidemic viral cause). We also discuss the evidence for seizures occurring in the context of antibody-associated encephalitis, an increasingly important condition. Finally, we describe the acute and longer-term management of encephalitis-related seizures and their potential pathophysiologic mechanisms, concluding with the emerging etiologic role of human herpesvirus 6.