Encephalitis Lethargica: The Great Unknown Sleeping Sickness of 1916 the Forgotten Pandemic that Lulled Victims to Sleep Before Death

During 1916, at the height of the First World War, it seemed to most observers as if death and dying itself had become the permanent state of humanity.

In February of that year French and German armies fought at the fortress city of Verdun in what, to this very day, still remains the largest and most deadly single battle in human history.  On July 1, 1916 more British soldiers were killed at the Battle of the Somme in one single hour than had been killed in all of the battles of the 19th century Napoleonic Wars combined.

However, the most deadly killer that emerged from the muddy trenches of Belgium and France killed silently; couldn’t be seen or heard by anyone and spread across the entire world within a matter of a few years and continued to kill, perhaps for decades, after the guns of the Western Front had long since fallen silent.

Today, thanks in part to the recent COVID-19 pandemic, even people without any interest in history at all know about the 1918 Spanish Flu pandemic--which, in fact, was American in origin and not Spanish at all it was simply reported on in newspapers in Spain at the time since the allied powers had a news blackout for anything negative emanating from the homefront.  The Spanish Flu Pandemic of 1918 was so deadly and devastating to post-World War One America that few of our ancestors could ever bring themselves to speak openly about it while they were alive, and research into the effects of the Spanish Flu only really began to creep into modern historiography during the twenty-first century when the pandemic itself had already mostly passed from living memory.  For over a century the Spanish Flu Pandemic of 1918--which killed millions of otherwise healthy and young Americans--remained largely a footnote to history until we all were, once again, forced to don surgical masks and stay home for our own protections in the year 2020.

The Spanish Flu Pandemic of 1918 may finally have gotten the historical coverage that it deserves in recent years, but at the time, there was another silent killer that literally rose up out of the mud, filth and blood of the rat-infested trenches of the Western Front.  This disease would kill its victims, almost without warning, by lulling them to sleep.  This disease was even more deadly, longer lasting and perhaps, even more scary to those who lived through it because, unlike the Spanish Flu, if this disease didn’t kill you it might literally make you go insane.

This disease was the Great Sleeping Sickness of 1916, which unlike the Spanish Flu which was born in the USA, was born in Europe as a highly contagious direct result of the Great War.  The epidemic caused worldwide by the Great Sleeping Sickness lasted for over a decade and a half and did not begin to dissipate in the United States and Europe until the early 1930’s.  The Great Sleeping Sickness came without warning and just as quickly as it appeared it seemed to inexplicably disappear.  

Trenches of WW1 Perfect for Disease

Even today, the Great Sleeping Sickness Epidemic (1916-1931) remains one of the greatest and most inexplicable medical mysteries of all time. Still, in our post-COVID 19 world the exact causes, nature, treatment and even spread and transmission of the Sleeping Sickness of 1916 remain a mystery.  Terrifyingly enough, the Great Sleeping Sickness of 1916--the same disease that caused history’s longest lasting worldwide epidemic--could, once again, strike at any time without any warning.

The medical name for Sleeping Sickness is Encephalitis Lethargica or EL for short in medical parlance.  EL is a disease that strikes the human nervous system and atrophies the brain.  Its onset is sudden and overtakes the victim seemingly overnight.  Initial symptoms of Encephalitis Lethargica include headache, sore throat and a low-grade fever in most cases--rather common symptoms not unlike those of a common cold--often those infected with Encephalitis Lethargica will attempt to “tough out” or “push through” their initial symptoms, but within twenty-four hours of the sore throat or headache the overwhelming lethargy and fatigue that gives the Sleeping Sickness its name will set in.

From that point on the sufferer will usually go to bed, or lay down on the ground, or the mud of a trench or wherever they happened to be--often being unable to stay awake for more than several minutes at a time.  At this point, when awake there will be constant yawning; periods of double vision and mad ravings interspersed with brief moments of lucidity.  Death for most who have contracted EL, at this point, will not be far off.

It is thought by historical researchers into the Great Sleeping Sickness of 1916 that the disease originated somewhere most probably in Romania sometime during the year 1915 in the trenches of the Eastern Front of World War One.  But, one trench is as good a disease-breeding hellhole as any other, and by the end of 1916, the disease that killed its victims by lulling them to sleep and driving them insane had migrated its way across Europe to infect that armies of Great Britain, France, Germany and Austria-Hungary on the Western Front.

At first, until the epidemic proved uniquely virulent and deadly, leaders in France and Great Britain in 1916/17--whose armies had recently had outbreaks of mutiny in light of the horrific casualties suffered at Verdun and on the Somme--believed that the symptoms of EL--the constant fatigue and the mental fog--were a type of dereliction of duty; a sort of new passive aggressive mutiny among soldiers who were either shell-shocked or attempting to shirk their responsibilities at the front.  But within one calendar year, by the end of 1917, the real dying from Encephalitis Lethargica set in--most prominently among civilians on the homefront--and by then everyone knew that the Great Sleeping Sickness Pandemic of 1916 was definitely for real.

It was thanks in large part to advancements in the study and understanding of human psychiatry that Encephalitis Lethargica was even diagnosed in the first place at the height of World War One.

In the summer of 1916 Dr. Constantin von Economo, an Austrian psychiatrist was summoned to an asylum outside Vienna to examine patients who were thought to be suffering from the psychological effects of either syphilis or multiple sclerosis.  When von Economo examined these individuals at the insane asylum he realized that he was dealing not with syphilis, or multiple sclerosis or even combat shell-shock, but rather, will a whole new deadly, and as yet, undiagnosed disease---Encephalitis Lethargica.

Across enemy lines at exactly the same time that Dr. von Economo was making his startling discovery, a French psychiatrist named Jean Rene Cruchet while working with traumatized soldiers in Paris reached the exact same conclusion and von Economo and diagnosed EL in his patients as well.  

In her remarkable book on the Sleeping Sickness of 1916 called Asleep: The Forgotten Epidemic that Remains one of Medicine’s Greatest Mysteries published in 2010, author and historian Molly Caldwell Crosby stated that after their initial diagnoses both Dr. von Economo and Dr. Cruchet believed that Encephalitis Lethargica, “(E)merged from the cold wet plains of northern France and Belgium--the battlefields of the Great War---and spread around the world.”

Modern historical research, like that undertaken by Molly Caldwell Crosby, now tells us that Cruchet and von Economo may have been wrong about from whence Encephalitis Lethargica originated, but that the spirit of their belief proved all too true.

It’s hard for us, today especially in light of the much more well known Spanish Flu Pandemic of 1918, to grasp how terrifying and long lasting the Great Sleeping Sickness epidemic really was.  It’s difficult to fully grasp the impact that it had on people at the time.  Its causes, origins, transmission and treatments remained mysterious to everyone in the world.  During the 1920s alone over 9000 scholarly articles were published worldwide on Encephalitis Lethargica and none of them reached any definitive conclusions about the origin or nature of the disease.

Many historians believe that Encephalitis Lethargica, and consequent epidemics of EL may have been nothing new to history in 1916--and many literary scholars assert that the disease could have been with us since the dawn of human civilization.  Literary scholars point out that characters like Rip Van Winkle and stories like Edgar Allen Poe’s “The Fall of the House of Usher” hint at past outbreaks of Encephalitis Lethargica that were recorded in the literary record of the time period but remained unknown to science.  Historians have also pointed out the similarities between the Great Sleeping Sickness Epidemic of 1916 and the supposed Great Sweating Sickness of the 16th century that ravaged Great Britain and western Europe and which I wrote about in an earlier article at Creative History that be accessed here:

https://creativehistorystories.blogspot.com/2024/06/a-rehearsal-of-hell-mysterious-english.html

Though Encephalitis Lethargica may be a plague that has affected humanity throughout history--as recorded in fables, fairy tales and literary traditions--the fact of the matter is that the specific outbreak which occurred worldwide between 1916 and 1930 carried with it a roughly forty percent mortality rate.  Over one million people in the United States are thought to have died of EL in that time span, but since much of the epidemic’s outbreak was concurrent with the Spanish Flu Pandemic of 1918, many deaths from Encephalitis Lethargica went either misdiagnosed or largely forgotten to history.

EL is and was a very distinct illness that was entirely separate in origin and in nature from the much more well-known “Spanish” influenza.  For one thing, even in 1916 narcolepsy was a well known and highly studied disease--Dr. Constantin von Ecomoo who first diagnosed EL in his patients noted the many similarities between narcolepsy and EL and he theorized that Encephalitis Lethargica could be a mutated and more virulent form of narcolepsy that somehow may have spread via human to human or animal to human transmission.

The truly scary thing about Encephalitis Lethargica and the 1916 epidemic is that despite all of the research, and the theories and despite the 9000+ plus scholarly articles that were published in the 1920s, very little to nothing is definitively  known about the disease.

Some cases suggest that Encephalitis Lethargica was a contagious airborne illness such as the August 1919 case of the Derbyshire Rescue and Training Home for Girls in England where it was documented that twelve of the twenty-one teenage girls who attended the school contracted EL over the course of two weeks, with half of those young girls tragically passing away from the disease.

However, an equal number of  cases suggest that contracting EL was not the result of airborne transmission and that people seemingly fell victim to the disease at random.  In London in the same year as the Derbyshire case of 1919 there was a well-documented instance of a nine year old child contracting and dying of EL who lived in a one bedroom apartment with his parents and five siblings.  The boy was the only member of his family to contract the sleeping sickness.

And then, around the year 1927 the Great Sleeping Sickness after killing millions in the decade after the Great War, simply vanished.  Most people who had survived their bout with Encephalitis Lethargica, approximately sixty percent more or less, made a full recovery from the illness but a staggering number of people who had fallen ill developed psychiatric illness, everything from clinical depression to anxiety to schizophrenia and bipolar disorder.  In some cases those who had become ill with EL in the 1910 and 1920s exhibited strange psychiatric symptoms--disassociations with reality--for decades after they had physically recovered from the disease.  Suicides as a result of EL related psychiatric disorders are thought to have continued well into the 1970s!

Today, the causes of Encephalitis Lethargica and its spread are still considered a complete riddle by most medical experts though research into the nature of the disease is constantly ongoing.  The Great Sleeping Sickness of 1916 appeared suddenly and without warning and then disappeared just as quickly and inexplicably as it had arrived---hopefully never to return…