Experimenting on the Past: The Enigma of von Economo's Encephalitis Lethargica

Abstract

Encephalitis lethargica (EL) was a complex and mysterious disease that appeared around the same time as the great influenza pandemic of 1918. The contemporaneous relationship of the 2 diseases led to speculation that they were causally related. Contemporary and subsequent observers conjectured that the influenza virus, directly responsible for the deaths of more than 20 million people, might also have been the cause of EL. A review of the extensive literature by observers of the EL epidemic suggests that most contemporary clinicians, epidemiologists, and pathologists rejected the theory that the 1918 influenza virus was directly responsible for EL. Disappearance of the acute form of EL during the 1920s has precluded direct study of this entity. However, modern molecular biology techniques have made it possible to examine archival tissue samples from victims of the 1918 pandemic in order to detect and study the genetic structure of the killer virus. Similarly, tissue samples from EL victims can now be examined for evidence of infection by the 1918 influenza virus.

Contemporary Encephalitis Lethargica: Phenotype, laboratory findings and treatment outcomes

“…The possible pivotal role of autoimmunity in the pathogenesis of EL was highlighted with the outbreak of EL [27] that followed the early 20 th century influenza virus pandemic [19]. The presence of anti-basal ganglia neuronal antibodies in sera, oligoclonal banding in cerebrospinal fluid of EL patients [8], steroid response [22] and negative virological tests [8] further implicate autoimmunity in the pathogenesis of EL.…”

Constantin von Economo (1876–1931) and his legacy to neuroscience

“…The epidemic was widespread to the USA and became pandemia in Europe and North America in the early 1920s. Peak of the disease was observed in 1923; nearly 2000 deaths in the USA were noted [6].…”

The Neuropsychiatric Consequences of Childhood Encephalitis: A Review of Cases from Middle-Eastern Countries

“…Although the epidemic has not recurred since then, isolated cases continue to be reported (Reid et al, 2001). The symptoms arise after a flu-like prodrome and include, fever, sore throat, headache, diplopia, alterations in consciousness, sleep inversion, catatonia and lethargy (Dale et al, 2004;Lishman, 2003).…”