Some doctors too reassuring about seizure riskPosted: 08/10/2013
You know how you’re not supposed to trust all the medical information on the Internet? Very true, and sometimes it’s actually the medical professionals who are placing material online that is oversimplified to the point of being misleading.
Trying to explain photosensitive epilepsy in a video of a minute and a half is pretty tough, and a Howcast clip that attempts to do that is just full of statements that make me very uncomfortable. It’s one of a series of videos on different aspects of epilepsy, but the presenters, despite their epilepsy expertise, aren’t necessarily experts in the specialty of photosensitivity. Photosensitive seizures are considered so out of the mainstream of epilepsy that few epilepsy specialists know a great deal about them.
The video in question, uploaded a year ago, features a pediatric epilepsy nurse and the Director of Pediatric Epilepsy at highly respected hospitals in New York City. My own qualifications for assessing the content of their video are found here. I’m quite certain that I’ve read more of the research on photosensitive epilepsy and seizures triggered by video games than anyone on the planet who isn’t a photosensitive epilepsy specialist. There are very, very few photosensitivity experts in the US.
This video downplays the overall prevalence/likelihood of photosensitive seizures, and it doesn’t address photosensitivity in people with no other seizures. And it overstates the conclusiveness of EEG for identifying seizure activity. Epilepsy clinicians and advocacy groups tend to want to reassure young patients and their families that in the vast majority of cases, video games and other flash-filled leisure pursuits don’t pose a seizure risk. While it’s good to encourage patients to live lives that are as normal as possible, the oversimplified message promotes the view that photosensitive epilepsy is quite rare and that doctors can know for sure, based on EEG testing, whether an individual should worry about video games as a seizure risk.
If you want to watch the video, please come back here to read my responses to what’s in it! Here’s a transcript with my comments in blue.
————————————————————————————————————————————————————————————————————-Nurse: “You know, whenever anybody comes into the office, they always ask us first thing whether epilepsy can be triggered by strobe lights, and people often think back to when the first Pokemon movies came out and all those children in Japan seized during the movies. So photosensitive epilepsy is something people worry about all the time.”
Two issues here:
1) Epilepsy is a condition that makes people vulnerable to seizures. It’s the seizures that are triggered; the epilepsy condition already exists. Why take issue with such a seemingly minor point? Being less than careful in how she worded things allowed a doctor in a WebMD video to incorrectly reassure viewers that video games cannot cause seizures!
2) The problem is much bigger than the population of epilepsy patients who come in to be evaluated by neurologists–people with no seizure history may develop photosensitive epilepsy (for example, the Navy pilot who can’t ever fly again after having a grand mal seizure while playing Oblivion: The Elder Scrolls IV). The general public, though–which presumably is the audience for this video–doesn’t worry enough about it. The epilepsy community should be doing more outreach to the general public to let them know they could be at risk.
Doctor: “On all the video games there’s those warnings that say, you know, you shouldn’t play this game in case you have epilepsy. But only one specific type of epilepsy has photosensitivity to it, and that’s a generalized epilepsy, that’s when the whole brain turns on all at once–”
This is what neurologists believed in the past. But numerous studies in the last 20+ years show this is not the case. A 1994 paper that included a review of other studies concluded that about 30 percent of photosensitive seizures are partial seizures—which do not involve the whole brain. The doctor’s statement could lead viewers to think that only people with generalized (typically grand mal) seizures need to worry about photosensitivity.
Nurse:…”lights up all at once, there’s a big burst of electricity through the whole brain. It’s one of the reflex epilepsies, so kids for the most part with epilepsy can play video games and can go under strobe lights unless they very specifically seize when they’re under strobe lights, and when we do the EEGs, we do the tests of their brain waves, we actually flash lights at them to see if it does create a seizure.”
The intermittent photic stimulation procedure used during EEG measures the brain’s reaction to a strobe light. The effect of a strobe light on the brain is not equal to the effect of playing a fast-moving, flashing video game. Some people who don’t respond to the strobe light can have seizures in response to video games or other visual stimuli. Studies of video game seizures frequently include individuals who experience seizures from games but do not test positive for photosensitivity. Photosensitive epilepsy in the research literature describes epileptic discharges on EEG in response to a strobe light in a laboratory. Some studies discuss non-photosensitive video game seizures: people who have the seizures even though a strobe light doesn’t produce signs of epilepsy on an EEG.
Doctor: “So by doing the EEG and flashing the lights in the child’s eyes, and having the EEG run at the same time, we can conclusively tell families whether the children can play video games or not play video games, and that will make a child very happy, hopefully finding out that it’s perfectly safe to play the video games and that they don’t have photosensitive epilepsy.”
EEG doesn’t conclusively rule out any type of seizure! It can confirm seizures but cannot rule them out since the technology does not detect all seizure activity. Some people who have seizures have normal EEGs. Oddly enough, in another video, What’s the Difference between Seizures and Epilepsy?” featuring the same clinicians in the same Howcast series, they contradict their statements in the first video, conceding that some seizures are too located too deep inside the brain to be detectable by EEG on the scalp.
7/19/2014 update: See information on a study showing just 6.2 percent of patients with visually induced seizures tested positive for photosensitivity in the photic stimulation EEG procedure.
Nurse: “As well as the teenagers and the young adults who will call or text and say, “Can I go–we’re going to a party and I know there’s going to be strobe lights. Is that OK?” So at least we have an answer for them after we’ve done the initial EEG.“
Photosensitive epilepsy is a genetic trait that is dormant until it becomes activated by a combination of factors. The most common time for the disorder to emerge is in adolescence. Thus a child who shows no signs of photosensitivity (again, based on testing with strobe lights, not video games) may later experience photosensitive seizures.
We need epilepsy clinicians and advocacy organizations to:
- be more concerned about the many visual stimuli in our environment that can trigger seizures
- think more broadly about who may be at risk–including members of the public who have no other seizures
- convey their concern about hazardous visual stimuli to the public, the digital entertainment industry, and lawmakers
- push for public policy changes that will rein in the stimuli and reduce the occurrence of visually triggered seizures.
- question reliance on EEG and photic stimulation to diagnose vulnerability to visually induced seizures
It’s a big job. It’s a much bigger undertaking than I can even imagine, but it needs to be done.