Imagine a disease where each day, even each hour, you simply feel more and more exhausted. For many of us, that may seem like a description of the average work week, but for those affected by Encephalitis lethargica, exhaustion just grew worse and worse, until trying to stay awake became an unbearable burden. They sat. They slumbered. They slept. And slept. For days. Then for weeks, and months, and years.
Truthfully, most of those affected were not so lucky as to just drift into something that would be seen as a gentle sleep. Many suffered everything from muscle weakness affecting one limb or another, to a crushing paralysis that gradually spread across their whole body. Many slipped from sleep into coma and died, often within a week or two of initial symptoms.
Some people awoke, recovered, and went on with their lives. Others never fully recovered. Many were left with physical issues, including paralysis that lingered for years, or for life. Double-vision was common. So were distortions of the facial muscles. Even more common were mental issues. People awoke from weeks of sleep with their personalities profoundly changed, with learning difficulties that didn’t exist before, and with a whole spectrum of other issues ranging from what we might now call “brain fog” to persistent dementia.
Some of those who eventually awoke reported that they had been aware for much of the time. They may have felt that people talking to them and trying to wake up were an irritant, wanting nothing more than to sink into deeper sleep. Or they may have felt like they were trapped in their own bodies, desperately wanting to wake, but unable to shake off the weight of sleep that seemed to press down on them.
Many of those affected were trapped in a kind of half-life, neither fully awake nor wholly asleep. Many had their eyes open. They could even get up and walk, if assisted. Their bodies had a peculiar, statue-like stillness. Left on their own, they would lie, or set, or stand where they were left. For days.
If any of this is sounding familiar, it may be because this disease also centers in Oliver Sachs’ 1973 book Awakenings, which became a film in 1990 with Robin Williams playing the role of Sachs (renamed “Malcolm Sayer” in the film). The patients depicted in that book and film were victims of Encephalitis lethargica, still going through their half-existence over 40 years later.
The cause of this disease is still unknown. Because it overlapped the massive flu pandemic, many have suspected for a long time that lethargica might be a “sequela,” that is, an after effect of infection by the 1918 H1N1 flu virus. This theory has fallen out of favor lately, but remains a serious possibility.