A 23 year old woman presents 8 hours after a convulsion. She was camping in the wilderness along with her partner, who witnessed the episode. He saw her collapse to the ground, with jerky movements of all four limbs and frothing at the mouth. This lasted for around 2 minutes. She has been persistently confused since recovering consciousness.

Her medical and surgical histories are unremarkable, but her family history is significant for a sister with epilepsy. She only drinks socially, is not on any medications, and does not use recreational drugs.