About a hundred years ago, the world faced a strange epidemic that made people sleep uncontrollably due to a condition known as “sleeping sickness.”
Victims were so sleepy that those who contracted it often did not wake up for weeks, or even months, at a time. The disease was also deadly, killing 30 to 40 percent of those infected, due to respiratory failure.
The disease appeared in northern France in 1916, causing people to fall into a deep, long sleep. It swept across Europe, then India, Central America, and North America, until it had almost completely disappeared by 1930. But to this day, no one knows exactly how it spread, what caused it, or whether the disease could come back.
Officially called sleepy encephalitis or sleep apnea, the disease initially causes flu-like symptoms, including headache, nausea, joint pain and fever. From there it spreads to the eyes, causing incoordination and then double vision. The eyelids then begin to droop, and patients become overwhelmed with the need to sleep day and night.
Although they could often be awakened, patients quickly returned to sleep, and many suffered from nightmares. However, some fell into a coma.
The emergence of sleeping sickness at about the same time as the Spanish flu pandemic has led some to believe that it may be linked to the H1N1 virus that killed up to 50 million people worldwide.
But analyses then and more recently, thanks to well-preserved brain samples, have shown no evidence of bacteria or viruses that could have triggered such a reaction.
Others believe it could be an autoimmune response, or an overreaction by the body to a cold or flu virus, rather than a result of the infection itself.
Although this is a plausible explanation, it does not answer how the disease appears and disappears so quickly.
Unfortunately, while the disease itself has stopped spreading, the lives of those infected have not returned to normal.
Many of them have Parkinson's disease, whose symptoms range from tremors to complete loss of the ability to move their muscles.