I was surprised to find out that as well as being the patron saint of love, St Valentine is also the patron saint of epilepsy. I’ve just found a study that analysed six centuries of artistic depictions of the holy figure where he is often accompanied by people having seizures.
The paper has a good description of St Valentine’s historical association with what was known as the “falling sickness” or “the sacred disease”. This link to the condition may be based on little more than the fact that his name sounds like the old German word for fall.
In Christianity, saints were of great significance in the treatment of severe and chronic illnesses, as their intercession with God was considered to have a great therapeutic effect on human ailments. In some illustrations of SV [Saint Valentine], the aspect of exorcising demons in connection with epilepsy is depicted as a demon flying out of the mouth of a sick person [see image on left].
Of the more than 40 named “epilepsy saints” (among others, Aegidius, Anastasia, Antonius, Cosmas, Cyriacus, Damian, John the Baptist, Ladislas of Hungary, Veit, Zeno), SV was the most well known and he was the saint who was invoked most often. Today, we can no longer verify whether his patronage was based on the phonetic use of his name with the word fall, as Luther had suspected, or on an incident in his legend (SV is said to have healed a person with epilepsy).
Two saints with the name Valentine were and are worshipped in the Roman Catholic Church: Valentine of Terni, patron saint day February 14, and Valentine of Rhaetia, patron saint day January 7. Valentine of Rhaetia is one of the patron saints of the Passau/Bavaria and Chur/Switzerland dioceses. People with epilepsy are portrayed in illustrations of both Valentine of Terni and Valentine of Rhaetia.
It is likely that two saints with the name Valentine had their patron saint day on February 14. Although the two SVs are sometimes entered separately in martyrologies and biographies, most scholars believe they are the same person. The patronage is complex, as SV’s help is invoked not only against diseases of cattle and pigs, but also against a host of human ailments, such as diseases of the uterus, gout, and, most notably, fainting, madness, and epilepsy. The use of pigs as attributes in illustrations of SV leads us to assume that there is also a reference to the description of the “healing of the demoniac of Gadara” (Mark 5:1–19; Lucas 8:26–40; Matthew 8:28–34). This passage in the Bible is interpreted as the curing of a person who possibly had epilepsy…
In medieval German language, the “falling sickness” was sometimes referred to as “St. Valentine’s illness, St. Veltin’s infirmity”.
The article is full of wonderful historical illustrations of St Valentine surrounded by or curing people with epilepsy, but sadly the article is locked behind a pay wall.
Link to PubMed entry for St Valentine art and epilepsy study.