apnea, which is when someone stops breathing or lead to a dangerous heart rhythm. oftentimes it happens in the sleep so it's hard to detect what the relationship was to the seizure, but that is known thing. it's sad and rare, thankfully, but that is likely the sort of thing we're talking ability here. >> you did say it's rare. how common is epilepsy in general and what can people do to lower their risk of something like this happening? >> when you think about epilepsy in the united states you probably have 3 to 4 million people who deal with epilepsy, who are taking medications to control that epilepsy. there may be more who even not received an official diagnosis, but you're talking about millions of people. again with sudep, which is sudden unexpected death, that's a rare thing. bullet we know there are certain situations that make it possibly more likely to happen. people who haven't necessarily taken medications as prescribed, we don't know that to be the