Real life Halloween Story: Sleepy Sickness – The Forgotten Plague

Forget the Russian Sleep Experiment (here for Sci-Fi fans), welcome to a literal, living nightmare.



Image Source: ‘The Russian Sleep Experiment’ – Skeptoid, URL:

Prepare to be spooked…

It’s the 1920s and a horrifying disease, Encephalitis Lethargica, has killed nearly a million people worldwide while doctors have no idea what is causing it.

You take your younger sister to the doctor for a sore throat, only to watch her descend quickly into an unnaturally deep sleep from which she cannot be roused. You then learn that she is actually fully conscious and aware of her surroundings, but will never wake to be the person she once was.

Many patients with what was commonly known as ‘Sleepy Sickness’ died during this state of catatonic somnolence (sleepiness) because they simply stopped breathing. Those who survived, woke in a state of psychosis so severe that patients would gauge out their own eyeballs, sexually assault others and display a complete loss of human emotion, becoming apathetic to the world as a whole.

Pretty terrifying right? Fear not, this mysterious disease disappeared as rapidly as it emerged. Scientists at the time were absolutely baffled and there is still debate over what caused the epidemic to this day, with theories that the disease was the result of the Spanish Flu. However patients began reappearing with encephalitis lethargica in the 2000s (though very rarely), which reopened the 80 year old cold case.

You can sleep easy tonight knowing that in 2004 scientists  finally found the culprit… this guy:



Image Source: ‘Streptococcus’ – Wikipedia: Rheumatic Fever URL:

Yep, that’s right. Streptococcus. Bacterial infections of the Central Nervous System are extremely rare thanks to our trusty blood brain barrier, but this is no ordinary infection.


The demon lies within…

The disease is actually not mediated directly by streptococcus, but it is the result of the immune response that was directed at that pesky sore throat. A number of immune hypersensitivity reactions have risen from streptococcus infections including post-streptococcal glomerulonephritis and rheumatic heart disease.

When your immune system attacks the streptococcus infection as it should, it develops antibodies (molecules that attack invading bugs) specific to the antigens on the bacteria that signal the immune system to kill them off. These antigens, which our body remembers and flags as dangerous, can sometimes look very similar to molecules in other parts of our body.

This is called antibody cross-reactivity, and in the case of encephalitis lethargica, our immune system starts recognizing antigens that actually belong to our brain as streptococcus. The immune cells start building up antibodies to attack our mid-brain and basal ganglia, acutely affecting balance and making the patient ‘sleepy’ (check out the seriously old vid below).


Years lost – the tragedy that followed

Despite being perhaps the scariest autoimmune disease in history, encephalitis lethargica did not always have a horror movie ending. Some patients made a full recovery, while others were left with permanent disability in the form of post-encephalitis Parkinsonism.

Those left in an apparently irreversible catatonic state lost years of their lives, confined to institutions, unable to move or speak, were compared to living statues. In the 60s Oliver Sacks (a famous psychologist) theorized that L-DOPA, a drug that stimulates dopamine in the brain, could be used to treat these patients and bring them ‘back to life’.

To end on a positive note, the return to life of these patients was the inspiration for  ‘Awakenings’ a film starring Robin Williams based on the book by Oliver Sacks. Despite losing forty years of their life, patients were ecstatic to be raised from the dead: