Like cancer, seizure disorders have existed throughout all of human history. Seizures in general can happen to anyone, and for a multitude of reasons.
Those with epilepsy, however, may have seizures frequently – and can experience several different types. The best known, due to their highly visible nature, are grand mal seizures. These seizures involve not just a change in consciousness, but tonic-clonic jerking movements of the limbs and head.
These types of seizures allowed both legitimate and illegitimate medical “experts” to conflate epilepsy with demonic possession well into modernity. This conflation even predated the Bible, and may have originated with the Babylonians, Greeks, and Romans – all of whom ascribed religious significance to what we know now as seizure activity. These early religious beliefs held that demons had possessed the afflicted, and that God was punishing the individual for it.
The fear of demonic possession and God’s punishment ingrained itself so deep into ancient societies that they had epileptics isolated, shunned, and subject to what we today would consider to be grisly treatment.
Indeed, those early “treatments” devised by the Romans involved the patient drinking the blood of fallen gladiators and eating the flesh of corpses, with these ceremonies influencing later “exorcisms.”