This has been an ongoing issue for me and I can't get a handle on it. I have probable SPS. I only have SPS. Never have lost awareness. Sole symptom is the onset of a burn smell. What is bothersome is that once the smell starts, it does not stop for quite some time. It persists for anywhere from 12-15 hours or longer. If the aura occurred in the morning, I will have the burn smell all day, go to bed, and when I awaken the next morning, the smell is gone. But if I get the aura late in the day. like 6 pm or later, I am looking at a 24 hour or longer occurrence of the smell. I am in an episode right now. Aura occurred at 6:15 yesterday evening and a night's sleep did not relieve it-I woke up with it persisting, so I am now looking at almost 28 straight hours. asleep or night, if I wake with it still there, it's as good as it never having left, and I know it didn't as I had awakened briefly middle of night with it still there. I can't possibly think I am having hours and hours of an ongoing seizure, but I assume the after effect of one. It just seems abnormal. I don't get the idea that other SPS people with olfactory auras have the burn smell persist for HOURS upon hours like this when they get it. On the bright side, I am having far less of these with a med change to Topamax (along with Keppra). Due to see neuro this week and hoping for an increase as I was just put on the Topamax 6 weeks ago. The auras are hugely reduced overall. The duration of the smell makes me think migraine which does get entertained too, but the abrupt onset of the aura leads my neuro to still speculate that E is in the mix and I could have both. The burn smell does get totally wearing of course.