In 1518, one of the strangest epidemics in recorded history struck the city of Strasbourg. Hundreds of people were seized by an irresistible urge to dance, hop and leap into the air.
In houses, halls and public spaces, as fear paralyzed the city and the members of the elite despaired, the dancing continued with mindless intensity. Seldom pausing to eat, drink or rest, 400 of them danced for days or even weeks. And before long, the chronicles agree, dozens were dying from exhaustion.
Video: "Chorea. The dancing lady."
In a spin: the mysterious dancing epidemic of 1518. Waller JC. Endeavour. 2008 Sep;32(3):117-21. Epub 2008 Jul 7.
Link via NCBI ROFL: Dance till you can't dance till you can't dance no more http://bit.ly/2qi0Jf
Enigma solved: Mona Lisa doesn't smile; she wears an expression common to people who have lost their front teeth, PubMed http://goo.gl/G60B9