Something is wrong with the brain - problem is always seen with scar tissue or abnormal metabolism . I.e. we see that the brain was damaged - or brain trauma. Abnormal metabolism - they might have been taking some crazy drugs or got sick. Scar tissue irritates neurons in the vicinity. This is cool.
Epilepsy takes the phenomenon of learning to a pathological extreme.
Now it is too easy for it to fire - i.e. slightest trigger and it will fire. Because during that time scar tissue is forming - we want to stop the chance of a seizure at all costs. If they get one - it will be easier to get another one. I.e. big waves with little spikes in them. Jacksonian March appears to march across the body - epilepsy spreads across the brain.