top of page
  • Writer's pictureArijit Bhattacharya

Encephalitis Lethargica, A mysterious epidemic

In our childhood, some of us might have played a game where we needed to stand like a statue on a call from one of us. And if someone was caught moving, then that person would be out of the game…


Now just imagine how it feels to stay in the same posture for a long time, Or I might say for months or years. You can see everything, hear everything but can’t respond to anything.

Horrible, right?

If we could time travel to 1915, then we can probably see this exact scenario in almost all houses in Europe. A mysterious disease came all of a sudden and caused one of the most dangerous epidemics the world has ever seen.

The disease I am talking about is Encephalitis Lethargica, popularly known as “Sleeping sickness”, a disease that swept the world during 1915-1926.

In this nearly 11 years of epidemic approx 5 million people were affected. And around 1927, this epidemic disappeared as abruptly & mysteriously as it first appeared. At the same time, the world was fighting another Pandemic caused by the Spanish flu. Encephalitis made it more complicated.

Due to lack of information, it was called an unknown terror between 1915-1917. It was then named Encephalitis Lethargica by Neurologist Dr. Constanin Von Economo. People then gave it a few more names, such as “Von Economo’s Encephalitis”, “Epidemic Encephalitis”, and “Brainstem Encephalitis”. It was spreading highly and the mortality rate was increasing day by day. The terror of 1915's encephalitis epidemic was then boosted by the Great Influenza Pandemic. At that time, few news articles claimed it was a sequel of the Influenza virus or was caused by the viral manipulation of the Spanish flu. These claims pushed the common people into the dark and made it more mysterious. But the scientists rejected these false claims.

Famous Neurologist Dr. Stern examined nearly 100 patients with Encephalitis Lethargica and has cured many of them. He defined the symptoms according to the reported cases; symptoms started with sleepiness and reached Parkinson’s Disease within a very short span. Many patients survived and made an almost complete recovery over time' But a majority of the patients developed post-encephalitic neurological conditions or passed away after a lengthy struggle. Many of the survivors developed a type of Parkinson’s disease, known as Encephalitic Parkinson’s. And in some cases, the severity of the disease has further turned into a very rare disease, Lewy Body Dementia.

In Dr. Oliver Sack’s words,

“They would be conscious and aware – yet not fully awake; they would sit motionless and speechless all day in their chairs, totally lacking energy, impetus, initiative, motive, appetite, affect or desire; they registered what went on about them without active attention, and with profound indifference. They neither conveyed nor felt the feeling of life; they were as insubstantial as ghosts, and as passive as zombies.”

The medical and pharmaceutical industries were trying their best to do something to cure the condition, but complexity and transmission rate stayed as an unbreakable barrier.

The tragedy of this epidemic made the world silent for almost a decade. It came abruptly and went mysteriously. After 1927, the rate of positive cases dropped all of a sudden and the epidemic ended within a month. Though isolated cases were occurring, somehow the world recovered from one of its historical epidemics. Even after 100 years, the mystery of that epidemic remains unsolved. Now various treatments are available on the early detection of the disease. Creating proper awareness is a much-needed thing, to detect the disease before it damages brain function. Even if it reaches its progressive stage, then symptomatic treatment helps fight the disease. The pharmaceutical industry and the neuroscientists are still working hard to find better and easily accessible treatments. Hope soon it will lose its remaining terror too…

I will come up with the details of the disease and some more exciting findings in my next blog, till then stay safe!!!

And remember,

Together we can fight COVID-19 pandemic too,

Follow the instructions given by WHO.

Let us make the environment safer for our next generation…


1. Discover Magazine. (n.d.). 100 Years Later: The Lessons of Encephalitis Lethargica. [online] Available at:

2. Dourmashkin, R.R. (1997). What caused the 1918–30 Epidemic of Encephalitis Lethargica? Journal of the Royal Society of Medicine, 90(9), pp.515–520. doi:10.1177/014107689709000916.

3. Hoffman, L.A. and Vilensky, J.A. (2017). Encephalitis lethargica: 100 years after the epidemic. Brain, [online] 140(8), pp.2246–2251. doi:10.1093/brain/awx177.

4. MedLink Neurology. (n.d.). Encephalitis lethargica. [online] Available at:

5. (n.d.). Encephalitis Lethargica - an overview | ScienceDirect Topics. [online] Available at:

Written and designed by Arijit bhattacharya


bottom of page