[adastra22]

I think you are most likely correct. However, I’m still very curious about this event. Those kinds of diseases are typically neural degenerate, and not often readily transmissible. What could cause an entire town to catch it simultaneously? Something in the water or food supply?

[red-iron-pine]

Ergot-ism.

Ergot is a fungus / mold that grows on grain, esp. types of wheat or rye. Rye in particular has a reputation. A whole towns supply of grain gets wet -- bad rains after harvest -- and everyone catches the ergot poisoning.

The toxins produced by ergot are vasoconstrictors -- they can often choke off blood pumping enough to cause gangrene in the weak / old / sick. Moving a lot, i.e. "dancing" forces the blood to pump harder and keeps your toes from dying from lack of oxygenated blood.

Ergot also contains a precursor to LSD, and is said to correlate with hallucinations. LSD itself was discovered by scientists trying to isolate ergot toxins for medical vasoconstrictor use (e.g. give a small dose to a surgery patient or something to minimize bleeding).

But basically your extremities are desperate for blood and you're tripping balls so you dance, move, etc. just to keep going.

[krylon]

I've heard of the hypothesis it was a fungus infecting the wheat. I don't know what it's called in English, it's Mutterkorn in German. Concidentally (or not?) the precursor substance of LSD is produced by this fungus.

[crazygringo]

It's "ergot" in English:

> One of the most prominent theories is that victims suffered from ergot poisoning, which was known as St. Anthony's fire in the Middle Ages. During floods and damp periods, ergots were able to grow and affect rye and other crops. Ergotism can cause hallucinations and convulsions, but cannot account for the other strange behaviour most commonly identified with dancing mania. [1]

[1] https://en.wikipedia.org/wiki/Dancing_mania

[krylon]

(slaps forehead) Of course. Thank you!