I plan on this week being my last of historical figures that lived with epilepsy. This time, I stumbled upon one that I found to be quite interesting. Many researchers have studied the evidence surrounding Joan of Arc's visions and auditory events and concluded that it points to a type of epilepsy called "idiopathic partial epilepsy with auditory features". Which means it had a genetic cause, only affects one part of the brain, and causes auditory hallucinations. This type of epilepsy would not cause your "typical" type of epileptic conditions. There would be no physical manifestation such as muscle spasms or postictal states. The symptoms would be auditory and sometimes visual hallucinations.
To the contrary of many people's concept of seizure activity, a seizure is when uncontrolled or unprovoked electrical activity occurs in the brain. This often times manifests itself as a muscle spasm, but depending on where the electrical activity occurs, it can mean things such as hallucinations can occur.
Joan of Arc claimed to hear mysterious voices and see visions during the Hundred Years' War between England and France. During her Trial of Condemnation, in which she was accused of being a heretic and witch, Joan of Arc claimed to have heard these voices and saw these visions. Eventually she was convicted of these accusations and burned at the stake, but her testimony was recorded and is available for review by anyone. She reported seeing hallucinations of saints such as St. Catherine and St. Margaret, also hearing voices. These voices and visions were said to have been brought on by the sound of bells ringing, and certain sounds triggering seizures is a well known and researched form of seizure initiation.
Joan of Arc also reported experiencing seizures during sleep. 40% of those living with the previously mentioned type of epilepsy experience seizures during sleep. Of course, diagnosing someone with epilepsy on verbal testimony alone is almost impossible. Which would leave one to believe that this will be forever left to speculation. However, it is a known fact that Joan of Arc sealed all letters she wrote with wax and a strand of her hair to prove the letter was from her. Since her type of epilepsy was genetic, if one of these letters were to be discovered, the diagnosis could be confirmed or disconfirmed rather easily. Until then, I guess we can't know for sure, but the signs are pointing to yes in this case.