100 Years Later: The Lessons of Encephalitis Lethargica

By Neuroskeptic | April 15, 2018 11:50 am

In 1917, at the height of the Great War, a new and mysterious disease emerged into the world, before vanishing a few years later. Although it was to prove less destructive than the 1918 influenza pandemic which occured at around the same time, the new outbreak had a persistent legacy: some of the victims of the disease remained disabled decades later.

The new syndrome was first reported by Constantin von Economo, a neurologist in Vienna. He dubbed the disease ‘encephalitis lethargica’, after its most dramatic acute symptom – lethargy, or sleepiness.

Patients in the acute phase of von Economo’s disease sometimes slept all day long. Others reported that they would fall asleep as soon as they sat down in a chair. Other acute symptoms included delerium, headache, and paralysis or abnormal movements of the eye muscles. Many patients recovered from this phase, only to face a cruel twist: months or years later, some victims developed severe Parkinson’s-like symptoms.

lethargicaLast month, the journal Neurology published a new paper marking 100 years since von Economo’s original description of encephalitis lethargica. The authors, Bart Lutters, Paul Foley, and Peter J. Koehler, describe the profound impact that the disease had, not just on medicine, but also on neuroscience.

The sleep symptoms that gave encephalitis lethargica its name were of great interest to von Economo and other researchers as they offered insight into the brain’s sleep centers:

The consistent pathology of the disorder allowed von Economo to localize the lethargic symptoms of encephalitis lethargica to the posterior wall of the third ventricle, near the oculomotor nuclei. Further, he traced insomnia, a disturbance paradoxically encountered in about 10% of encephalitis lethargica cases, more anteriorly, to the lateral walls of the third ventricle, near the corpus striatum.

For von Economo, these clinicopathologic findings confirmed the existence of a subcortical sleep-regulating center. During sleep, this center would actively inhibit the cerebral cortex, reducing the level of consciousness.


von Economo’s hypothesis of a sleep generating centre turned out to be not quite correct, however, as it was later discovered that a sleep preventing centre (arousal centre) actively acts to keep the brain awake. Damage to this region is thought to occur in encephalitis lethargica.

Lutters et al. explain how the outbreak also advanced our understanding of Parkinson’s disease. Post mortem studies of the brains of patients with post-encephalic Parkinson’s lent strong support to the theory that Parkinson symptoms are caused by damage to the substantia nigra, a much-debated hypothesis that turned out to be correct.

In the 1960s, when it was discovered that the drug L-DOPA is able to reverse the symptoms of Parkinson’s, the drug was tried on post-encephalitic patients, some of whom had remained virtually comatose for 40 years or more. As described in Oliver Sacks’s famous book, Awakenings, L-DOPA produced remarkable effects, although in many cases they were, unfortunately, only transient.

Even 100 years later, the cause of the encephalitis lethargica epidemic remains uncertain. One theory is that the co-occurence of the encephalitis and the 1918 influenza pandemic was no coincidence, and that the influenza virus somehow affected the brain in some cases, causing encephalitis lethargica. Others believe that a virus related to the polio virus was the cause.

CATEGORIZED UNDER: history, papers, select, Top Posts
  • https://plus.google.com/u/0/101046916407340625977/posts Rolf Degen

    There is also a whole new book on the subject, that one too by the paper’s co-author Paul Bernard Foley, again making the case that Adolf Hitler probably suffered from the disease. https://link.springer.com/book/10.1007/978-1-4939-0384-9

  • Neuro_Seance

    If this had happened now, for the first time ever, instead of back then, how long it would take for experts to consider an organic cause? It seems like we’d have to slog through melancholia, mass hysteria and malingering first. If plenty of SSRI/SNRI antidepressants and adjunctive atypical antipsychotics were thrown at it in phase M1, any observed Parkinsonism might be misunderstood as adverse effects of the failed drug therapies.

    Lacking any useful knowledge of what this disease is and what SSRIs actually do, I can only offer a guess about likely effects of SSRIs and SNRIs on the NE-afflicted. Possibly hellish. I wonder if they tried amphetamine during the 1917 epidemic.

    • http://blogs.discovermagazine.com/neuroskeptic/ Neuroskeptic

      Well, I’m not sure SSRIs are relevant here. But I agree, if encephalitis lethargica happened today, it might be ascribed to a psychogenic cause by some. Then again certain symptoms of the acute phase (fever, oculomotor symptoms) would strongly argue against that.

  • Andrea

    My husband was diagnosed with Encephalitis Lethargica in January 2015 after being hospitalized for 10 days in December of 2014 with Influenza A H1N1.

    During his hospitalization I told the doctors and nurses that something was really wrong with his mental state and they all said it was “normal for the flu.” He didn’t get discharged home after the flu, he was discharged to a rehab center because he couldn’t walk, speak clearly or remember things. The rehab center was sub par so I had him discharged AMA and we went the route of outpatient physical, speech and occupational therapy.

    He was initially on L-dopa (same drug as in Awakenings) but after a year he had lost a lot of weight because the L-dopa made him throw up. He is unable to work, suffers Parkinsonism (constant shaking), muscle and limb pain, severe headaches, expressive aphasia, memory loss, attention issues and sleep inversion.

    To me, it seems obvious that Influenza and Encephalitis Lethargica are linked.

    I might buy the book that Rolf recommended, however, it will have to wait until I have an extra $200 to purchase it. (Yikes, maybe the library at the college I teach at part time will have it!)

    • Maria Taheny

      I am so sorry your husband endured this but, as a psychological clinician, this information is valuable to me. I work with elders and see this development after illnesses in some clients. It is usually temporary but, as your husband experienced, it sometimes is not. The brain is amazing and I have personally seen miracles happen when a person is under 40.

      Prayers for him and you. Never lose hope!



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Neuroskeptic is a British neuroscientist who takes a skeptical look at his own field, and beyond. His blog offers a look at the latest developments in neuroscience, psychiatry and psychology through a critical lens.


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