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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Encephalitis lethargica | 2/2 | https://en.wikipedia.org/wiki/Encephalitis_lethargica | reference | science, encyclopedia | 2026-05-05T11:04:25.215156+00:00 | kb-cron |
In 1580, Europe was swept by a serious febrile and lethargic illness that led to Parkinsonism and other neurological sequelae. From 1673 to 1675, a similar serious epidemic occurred in London, which Thomas Sydenham described as "febris comatosa". In 1695, a 20-year-old woman in Germany experienced oculogyric crises, Parkinsonism, diplopia, strabismus, and other symptoms following an attack of somnolent brain fever, as described by Albrecht of Hildesheim. In 1712–1713, a severe epidemic of Schlafkrankheit ('sleep sickness') occurred in Tübingen, Germany, followed in many cases by persistent slowness of movement and lack of initiative (aboulia). Between 1750 and 1800, France and Germany experienced minor epidemics of "coma somnolentum" with features of Parkinsonism, including hyperkinetic hiccup, myoclonus, chorea, and tics. Between 1848 and 1882, Paris-based neurologist Jean-Martin Charcot documented many isolated cases of juvenile Parkinsonism, associated with diplopia, oculogyria, tachypnoea, retropulsion, and obsessional disorders, which were almost certainly post-encephalitic in origin. In 1890 in Italy, following the influenza epidemic of 1889–1890, a severe epidemic of somnolent illnesses (nicknamed the "Nona") appeared. For the few survivors of the Nona, Parkinsonism and other sequelae developed in almost all cases. Between 1915 and 1927, a world-wide encephalitis lethargica pandemic occurred, impacting nearly 5 million people and killing an estimated 1.6 million people.
=== Pandemic of 1915–1927 ===
In the winter of 1916–1917, a "new" illness suddenly appeared in Vienna and other cities, and rapidly spread worldwide over the next three years. Earlier reports appeared throughout Europe as early as the winter of 1915–1916, but communication about the disease was slow and chaotic, given the varied manifestation of symptoms and difficulties disseminating information in wartime; it was officially recognized as a distinct disease in 1917. Some authors define the span of the outbreak as being from 1918 to 1930. Neurologist Constantin von Economo published a paper in April 1917 describing some of the cases he encountered in the winter months of 1916–1917. These patients, despite varying diagnoses, had a similar pattern of symptoms which led von Economo to suggest a novel disease, which he called Encephalitis Lethargica. In France, physician Jean-René Cruchet was experiencing something similar, and he published his findings within a few days of von Economo.After these two, many more reports began being released about the disease, starting in Europe before moving around the globe. Until Constantin von Economo identified a unique pattern of damage among the brains of deceased patients and introduced the unifying name encephalitis lethargica, reports of the protean disease came in under a range of names: botulism, toxic ophthalmoplegia, epidemic stupor, epidemic lethargic encephalitis, acute polioencephalitis, Heine-Medin disease, bulbar paralysis, hystero-epilepsy, acute dementia, and sometimes just "an obscure disease with cerebral symptoms". Just 10 days before von Economo's breakthrough in Vienna, Jean-René Cruchet described 40 cases of "subacute encephalomyelitis" in France. The number of people infected during the ten years of the pandemic is unknown, but it is estimated that more than 1 million people contracted the disease, which directly caused more than 500,000 deaths. Encephalitis lethargica assumed its most virulent form between October 1918 and January 1919. In the United States, the epidemic peaked from 1920 to 1924. It is estimated that as many as one million people were diagnosed with encephalitis lethargica during the epidemic period. The pandemic disappeared in 1927, as abruptly and mysteriously as it first appeared. The great encephalitis pandemic coincided with the 1918 influenza pandemic, and the influenza virus likely potentiated the effects of the causative agent of the encephalitis or lowered resistance to it in a catastrophic way.
==== Aftermath ==== Many survivors of the 1915–1927 pandemic seemed to make a complete recovery and return to their normal lives. However, the majority of survivors subsequently developed neurological or psychiatric disorders, often after years or decades of seemingly perfect health. Post-encephalitic syndromes varied widely: sometimes they proceeded rapidly, leading to profound disability or death; sometimes very slowly; sometimes they progressed to a certain point and then stayed at this point for years or decades; and sometimes, following their initial onslaught, they remitted and disappeared. It is also known to cause postencephalitic parkinsonism (PEP). Though often thought of as a disease of the past, it is still seen in occasional cases today.
== Notable cases == Notable cases include:
Muriel "Kit" Richardson (née Hewitt), first wife of actor Sir Ralph Richardson, died of the condition in October 1942, having first shown symptoms in 1927–1928. There is speculation that Adolf Hitler may have had encephalitis lethargica when he was a young adult (in addition to the more substantial case for Parkinsonism in his later years). Mervyn Peake (1911–1968), author of the Gormenghast books, began his decline towards death which was initially attributed to encephalitis lethargica with Parkinson's disease–like symptoms, although others have later suggested his decline in health and eventual death may have been due to Lewy body dementia. Those described in the book Awakenings by the British neurologist Oliver Sacks. Jane Norton Grew Morgan, wife of J. P. Morgan Jr., died of encephalitis lethargica in 1925. At the time, doctors attributed her encephalitis to having contracted influenza during the 1918 pandemic.
== See also == Idiopathic disease Idiopathic chronic fatigue Chronic fatigue syndrome Fever of unknown origin
== References ==
== Further reading ==
== External links ==
Encephalitis Lethargica at NINDS "Mystery of the forgotten plague". One-Minute World News. BBC News. 27 July 2004. Medical Mysteries: The Forgotten Plague was broadcast on BBC One on 28 July [2004] at 22:35 BST. — item about the tracing of the infectious agent in encephalitis lethargica