He observed that the causes of the condition were unknown, but that the subjects affected were "mostly of the female sex, and chiefly between the ages of sixteen and twenty three" although he also qualified this statement by adding that he had occasionally seen it in males of the same age.
Pobadal, že príčiny tohto stavu boli neznáme, ale postihnutí boli „hlavne ženského pohlavia a prevažne vo veku medzi 16 až 23 rokov“, hoci pridáva, že občas to spozoroval aj u mužov v tomto veku.