“Hysteria” in LeRoy: A Skeptic’s View

This is an interesting case, not because of any interplay with Spiritualism but about what happens in the human mind. Ther are plenty of news stories about it but this is a thoughtful piece.
http://psychcentral.com/blog/archives/2012/02/13/hysteria-in-leroy-a-skeptics-view/

""We have conclusively ruled out any form of infection or communicable disease""

Indeed. Absolutely?

But not cyanide poisoning or some inherently communicated psychiatric hysteria. Now would that not prove the existence of Sir William Crookes Psychic Force?

Ergotamine?