Epilepsy is named after a Sicilian martyr. Around the same time as St. Erasmus’ victory, a 12-year-old boy named Vitus also won the palm of martyrdom, with his companions Modestus and Crescentia. According to some sources, a rather odd devotion to the saint, involving dancing, developed in the Middle Ages in Germany (where his relics had been brought in the ninth century). The sad effects of epilepsy, which causes its sufferers spasmodic seizures, apparently resembled this dance enough that the disease came to be called “St. Vitus’ Dance.” Naturally, he came to be invoked as the patron of those who suffer from epilepsy. He is also the patron of any who suffer from oversleeping. This last fact is attributed to a detail of his martyrdom: While he was being boiled in oil, a rooster was thrown in with him as part of the pagan sacrifice. The symbolism of the rooster as an “early riser” was transferred to the martyr. June 15 is the feast day of St. Vitus and his companions.
Note: In more recent times, Saint Vitus Dance is the name given to Sydenham’s chorea.