Encephalitis Lethargica: The Sleepy Sickness of the 1920s
Robin Williams and Robert De Niro in Awakenings. Source: (oscarchamps.com)
In the 1990 film Awakenings, Robin Williams starred as a 1960s doctor working with patients who had been left catatonic due to a 1920s epidemic of a mysterious illness. The movie, based on the book of the same name written by Dr. Oliver Sacks, was inspired by real events and the mysterious illness was Encephalitis lethargica, also known as von Economo disease or “sleepy sickness.”
While the sickness didn’t reach epidemic proportions until after the end of World War I, the earliest cases appeared among the soldiers around 1915 or 1916. These soldiers experienced symptoms including lethargy and confusion. They were examined by doctors in Paris who initially believed the symptoms to be a reaction to the mustard gas used during the war, but that idea was later disproved when the same symptoms began to appear among civilians.
The symptoms were observed by a neurologist from Vienna named Constantin von Economo. In 1917, he published a paper on his observations entitled “Die Encephalitis lethargica.” In his paper, he described the illness as “a kind of sleeping sickness.” According to his observations, the early symptoms included headaches and uneasiness, followed by drowsiness and delirium. In some cases, the delirium led to death while others resulted in a persistent catatonic state.
Von Economo went on to detail variations in the presentations of the illness. He identified the hyperkinetic form which involved rapid motor movements, twitching, anxiousness, insomnia, and restlessness. Another form, the amyostatic-akinetic form, presented similarly to Parkinson’s Disease. But the deadliest form, somnolent-ophthalmoplegic, was characterized by the subject falling asleep at random times before slipping into a comatose state. Those with the third form who didn’t die were left in a catatonic state like the patients in the aforementioned movie.
A few years after von Economo published his paper, the disease began spreading across the globe, infecting millions, most commonly young people between the ages of fifteen and thirty-five. The final death toll was one million but many more were left trapped inside their own bodies. It is estimated that about forty percent of the affected died, twenty percent were left in a permanent vegetative state, twenty-six percent recovered but with lingering complications and only fourteen percent recovered completely.
The sleepy sickness epidemic came in on the heels of the much larger Spanish flu pandemic which wiped out fifty to one hundred million people across the globe and the two conditions were initially thought to be connected. However, other than timing, the two illnesses had very little in common. More recent research has linked the condition to a very rare form of streptococcus, aka strep throat, during which the immune system overreacts and begins attacking parts of the brain. Sadly, knowing what causes it does not equal knowing how to cure it.
While the epidemic died out about ten years after it began, doctors were still left with the puzzle of how to treat the survivors. Steroids were somewhat effective against the hyper-kinetic form, but the somnolent form was far less treatable. In the 1960s, Dr. Oliver Sacks discovered that the drug Levodopa could somewhat alleviate the symptoms, allowing these patients to “wake up” for the first time in decades. However, as indicated by the heartbreaking conclusion of Awakenings, this proved to be only a temporary cure and the patients eventually developed a tolerance to the drug and slipped back into their vegetative states. To this day, the cause of the epidemic remains a mystery and there is still no cure. And while this illness is rare, it is by no means eradicated as there have been several isolated cases since the disease made a reappearance in 1993.