The 5 Most Terrifying Diseases That Doctors Can't Explain

5 The Sleeping Sickness

Imagine your spouse comes down with what you assume is a bad cold. But after getting worse over the next few days, she suddenly freezes like a statue, eyes blank and vacant, mouth contorted in a silent scream. She just lies like this, motionless, in a hospital bed. Then finally she wakes up, and acts like she's possessed by a goddamned alien body snatcher -- she's emotionless and distant at first, then starts gouging at her eyes and/or violently sexually assaulting people.

It's not the first act of a horror movie, but a real, baffling disease that had doctors puzzled at the beginning of the 20th century. It's called encephalitis lethargica, or the sleeping sickness, and it struck the world as an epidemic just after the Spanish flu died down. Nobody has any idea where it came from or where it went.

It began with victims complaining of a sore throat, right before it escalated into a goddamned living nightmare, the victims afflicted with hallucinations and madness before their bodies ultimately locked up. While sufferers appeared to be asleep, they were actually fully conscious but unable to move. Many died during this stage, but for those who recovered, the nightmare was far from over.

Survivors of the sleeping disease suffered horrifying behavioral problems for the rest of their lives, becoming excessively violent and -- regardless of gender -- somewhat rapey. On top of all this, they became emotionally indifferent, unable to recognize, for example, the beauty of art. Ten years after the epidemic struck, new cases suddenly stopped appearing, its only legacy being the alien clones it left behind.

Nearly a century later, doctors still don't know what the hell was going on there, although they realize it was some kind of brain thing. One hypothesis is that the bacteria that caused the sore throat triggered an immune response that also destroyed parts of the brain, but many scientists still think a virus is the more likely culprit.

In the meantime, the occasional case still crops up, to the scratching of many heads. Now try not to think about this the next time you get a cold, you poor bastard.

4 Jumping Frenchmen of Maine

Due to either a healthy sense of humor or an absolute lack of imagination, neurologists have settled on "Jumping Frenchmen of Maine disorder" to describe the bizarre condition first documented in the northern parts of Maine by George Miller Beard in 1878. That's when Beard noticed that a lot of the French Canadian lumberjacks of the region were, uncharacteristically, jumping and screaming like little girls at the slightest provocation.

And even weirder, victims dealing with Jumping Frenchmen aren't just easily spooked -- sufferers will enact basically any simple command, as long as you shout it at them suddenly, like "throw that beer" or "kick that stool" or even "punch that guy." It's apparently due to some heightened state of suggestibility, combined with an overactive startle reflex that turns victims into short-term robot slaves. And no, this is not a good thing to have when you are frequently found holding a giant axe.

The absurdly specific disease appears endemic to parts of northern Maine, and is largely restricted to those French Canadian lumberjacks, which suggests that it may be genetic, or else it's environmental, or somehow psychological, which all together rule out practically nothing. Some victims also display signs of echolalia (automatically repeating sounds they hear), which led some to believe that they suffered from either a form of Tourette's or being a giant parrot in a human-skin suit, but investigations show it doesn't appear related to either condition.

3 Nodding Syndrome

Around 2010, a mysterious disease came to the attention of medical professionals when it cropped up in East Africa, which is saying something, because there are so many awful diseases out there that it can be difficult to track them all. It's called nodding syndrome, and for good reason: Victims are struck by an uncontrollable head-nodding, as if they are forever enjoying a catchy song that only they can hear.

The condition was actually first described in Tanzania in the 1960s, but little attention was ever given to it, doctors having probably written it off as an outbreak of extreme enthusiasm. But in recent years, the disease has returned in epidemic proportions, and despite the large number of cases, doctors are pretty much stumped.

In addition to the nodding, the disease also stunts children's growth somehow so that they can appear much younger than they are. And the nodding thing is most often triggered by cold temperatures or eating. The fact that people afflicted by this condition often become malnourished is for obvious reasons -- imagine trying to eat while uncontrollably nodding.

The best guess about the origins of nodding syndrome is that it has something to do with a parasite common in the area, but this doesn't explain why most people who get the parasite don't get the nodding part.

Many of the locals, on the other hand, believe that the disease is caused somehow by Joseph Kony, the brutal warlord made famous by that viral video earlier this year. Hey, why not?

2 Brainerd Diarrhea

If you've ever experienced the horrible consequences of a bad sushi restaurant, then you'll know the pain of shitting like a garden hose for a miserable day or so. Imagine doing that for months on end, and you'll have some idea of what it's like to come down with Brainerd diarrhea.

The disease gets its name from the town of Brainerd, Minnesota, where the first known case occurred, and which has the dubious honor of being the only town to lend its name to an explosive case of the buttsquirts. People afflicted with this condition typically experience 10 to 20 episodes per day, often accompanied by nausea, cramping and fatigue, possibly caused by running a daily toilet marathon while screaming "Oh God, oh God."

And these spells can last up to a year.

Eight outbreaks of Brainerd diarrhea have been reported since 1983, out of which six occurred in the United States. The original was the largest, with 122 people inflicted with a yearlong fire-hose butt. Beyond that, nothing much can be said about it -- there's some evidence that you get it from unpasteurized, raw milk, but doctors can't identify any specific reason for it beyond God's cruel imagination.

Hey, speaking of terrifying poop diseases ...

1 Porphyria, the Vampire/Purple Shit Disease

People who suffer from porphyria experience a constellation of equally terrifying symptoms: Their gums recede to give the appearance of fangs, their skin bubbles and boils when exposed to sunlight and they can only be treated with injections of blood. If this sounds familiar to you, you're not the only one -- it has been theorized that porphyria sufferers contributed to the vampire legend.

Unlike most of the vampire tales we grew up with, however, sufferers of this particular disease tend to poop purple. There's also crippling abdominal pain and "mental disturbances," which probably come as a result of squeezing out a bright-purple turd.

Porphyria is caused when heme, a part of hemoglobin, isn't produced properly. As to why is literally anybody's guess. Scientists state that this could be because of a mutation in the DNA, but that doesn't explain why alcohol, drugs, infections and even estrogen could trigger attacks of certain types of porphyria.

Scientists note that they've identified a gene mutation that's associated with having the disease ... in 20 percent of people. They also note that 80 percent of cases have no such mutation, which they probably reported with a bewildered shrug. What we're saying is there's always a chance that, one day, you too might crap purple and then develop an unstoppable urge to bite your neighbor.

For more terrifying things we have no answers for, check out 6 Terrifying Diseases That Science Can't Explain. Or discover 7 Horrible Ways the Universe Can Destroy Us Without Warning.

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