Encefalitis letárgica. La epidemia en los albores de la neurología / Encephalitis lethargica. The epidemic at the dawn of neurology

La encefalitis letárgica es un cuadro neurológico con una variada gama de manifestaciones clínicas en el ámbito neurológico y también en el psiquiátrico. El cuadro se ha presentado de manera epidémica en brotes que han seguido a los de la gripe. El último brote acaecido a comienzos del siglo XX lo describió en profundidad Constantin von Economo. La epidemia notificada inicialmente en Europa y luego en Norteamérica se presentó también en otras latitudes, incluyendo Chile. Así, las descripciones de Lea-Plaza, Tello, Iturra, Cienfuegos y otros médicos chilenos dieron cuenta del cuadro en Chile con toda la complejidad que también tuvo en Europa. El origen sigue siendo un misterio, aunque la evidencia creciente de que fuera autoinmune gana fuerza con los hallazgos de la tecnología médica actual. En este trabajo presentamos el cuadro, privilegiando la riqueza clínica y la belleza de las descripciones realizada por los médicos de la época en que esta enfermedad se presentó

Lethargic encephalitis is a neurological illness that shows a wide range of symptoms and signs, including neurological and psychiatric spectrum. It presented in an epidemic way, following influaenza relapses. The last relapse started at the beginning of 20th century and it was deeply described by Constantin von Economo. The illness described first in Europe and North America, was described in many others countries including Chile. There were beautiful descriptions by Chilean physicians like Lea-Plaza, Tello, Iturra and Cienfuegos. Their works showed the complexity of the illness like European physicians did too. The etiology is still unknown; however growing evidence about autoinmune aetiology is gaining force with the use of actual medical technology. In this work, we show encephalitis lethargica, focusing in clinical picture, the beauty of medical descriptions that physicians did at this date

On doing nothing: descriptions of sleep, fatigue, and motivation in encephalitis lethargica.

Epidemics of encephalitis lethargica (EL), from 1917 to the 1930s, are an important milestone in the history of movement disorders. Today, the two best-known features of EL are somnolence and parkinsonism but the full clinical picture was variable and complex. States of wakeful inactivity--as opposed to drowsiness--were often described both in the acute and postacute stages and were referred to in the EL literature as "lethargy" or "torpor." The study described here is based on a survey of clinical descriptions published in English, French, and German from 1917 to 1942. Its focus is on the history of clinical ideas, rather than applying modern pathophysiological concepts retrospectively. Descriptions of lethargy are explored as a way of elucidating concepts of sleep, fatigue, and motivation during the study period. The literature described many patients who had (1) lethargy without interruption in consciousness; (2) slowness of movement and catalepsy without other prominent parkinsonian features; and (3) apathy and lack of initiative without severe disorders of mood or thought content. Hence observers distinguished a state of wakeful inactivity from primary disorders of sleep, movement and behavior. Contemporaneous accounts suggest that writers had difficulty in reconciling their observations with preexisting concepts; there still may be limitations in our ability to describe and classify the clinical states connected during the epidemic era with the term "lethargy."

[How did encephalitis lethargica affect Spain? An analysis of the cases reported between 1918 and 1936]. / Cómo fue la encefalitis letárgica en España? Análisis de los casos publicados entre 1918 y 1936.

AIM: Encephalitis lethargica spread as a pandemic over the period 1918-1921. Clinically, it displayed an important degree of polymorphism and the clinical presentation varied from one outbreak to the next and from one region to another. Few studies have been carried out on the encephalitis lethargica epidemic in Spain. To determine the characteristics of its clinical and developmental features, we reviewed the cases reported in the Spanish medical literature over the period 1918-1936. DEVELOPMENT: A total of 120 cases were analysed. Most of them (75%) occurred during the winter of 1919-1920. The mean age was 27 years (range: 0-59 years). Most of them presented feverish syndromes (82%). The most frequent neurological symptoms were disorders affecting the cranial nerves, especially the oculomotor nerves, sleep rhythm disorders, altered mental or conscious status, pupillary abnormalities and movement disorders. Important variations were observed in the clinical presentation and in the developmental course. Although most cases did not present pure clinical forms, the predominant forms were somnolent-ophthalmoplegic (46%) and hyperkinetic (17%), which were associated with delusions with chorea or myoclonias. The most uncommon were amyostatic forms (Parkinsonian, 4%). The mortality rate was 23%. Most of the survivors (69%) were cured in the acute phase with no significant sequelae. CONCLUSIONS: The maximum incidence of encephalitis lethargica in Spain was registered during the winter of 1919-1920. It presented an important degree of clinical polymorphism, with predominance of an association between lethargy and ophthalmoplegia, and was linked to a high mortality rate.