A continuum of visual sensitivity

Even readings outside the red zone may indicate the need for caution.

If a neurologist tells you that you don’t need to worry about seizures from electronic screen exposure, because you’re not photosensitive, what does that really mean?

It means that when you were tested for your response to a white strobe light, an EEG didn’t detect a particular abnormal electrical pattern in your brain. (I’ve noted some limitations of this procedure elsewhere.) Epileptology looks for yes or no, typically relying on EEG to rule out epilepsy. If yes, possibly medicate; if no, it’s not a case the clinician will pursue.

It does not indicate that bright flashing and/or patterns from electronic screens don’t adversely affect your brain function.

Researchers have gradually come to consensus on exactly what the EEG must look like to indicate photosensitive epilepsy (the photoparoxysmal response): certain spike/wave patterns that appear in both brain hemispheres. In arriving at these criteria, researchers excluded three other types of EEG abnormalities that in prior research “qualified” as a photoparoxysmal response. Epilepsy researchers aren’t certain what the significance of these other abnormalities is, but because the other patterns cannot conclusively be associated with epileptic seizures, there’s little interest in further research.

So these other EEG abnormalities from photic stimulation don’t count, in current neurology practice, and nobody would even tell you about them if they were found in your EEG. You’d be told the EEG was normal, period. But what if these other abnormalities were a sign that neurological function is in fact disturbed by visual stimuli, but not to the point of a seizure?

Let’s say you had one of the three other EEG abnormalities (which you wouldn’t know about, because the EEG was deemed normal). Maybe these indicate that you’re vulnerable to symptoms of a visual-overload-not-to-the-point-of-seizures syndrome. Neurologists have been examining the overlap between epilepsy, photosensitive epilepsy, and migraines. More about this in a future post, but actually there are many overlapping symptoms and correct diagnosis can be difficult. So if video game exposure or photic stimulation produces headaches and visual disturbances, and an inconclusive EEG, it may be that the visual overload is triggering migraines. Or perhaps the exposure is triggering another form of hyperexcitability in the brain’s visual cortex, which has been termed visual stress. While research has been done on this, it’s not part of a conventional neurology practice.

What about patients with more subtle or mood-related symptoms of a visual-overload-not-to-the-point-of-seizures problem? Who is treating these patients? Could be psychiatrists and psychologists, who view altered behavior and cognitive function through the lens of their respective training. Because there’s such a dearth of research of the gray areas of brain dysfunction following exposure to electronic screens, mental health providers have no basis for treating these patients for anything but mental health disorders. It’s clear that more research is needed and that more effects on the brain will be uncovered. One intriguing paper explores the contribution of fluorescent lighting to agoraphobia. The SpongeBob study published last year showed diminished executive function in children who viewed the cartoon.

In her Psychology Today blog, psychiatrist Victoria Dunckley recently posted a compelling piece about the effects on her patients of electronic screen time. She recommends creating a diagnostic category called Electronic Screen Syndrome to identify a dysregulation of mood, attention, or arousal level due to overstimulation of the nervous system by electronic screen media. She has seen dramatic improvements in hundreds of patients’ mood, behavior, and cognition after they go on an “electronic fast.” (Some have underlying psychiatric diagnoses, some don’t.) Maybe these patients were having very subtle seizures from electronic screens. Maybe the effects on the nervous system weren’t quite what epileptology defines as seizures. Either way, many kids exposed to electronic screens are experiencing diminished quality of life (as are their families) for a problem that medicine has not yet acknowledged.

Photosensitive epilepsy = Purple Day epilepsy?

Does Purple Day have meaning for those with photosensitivity?

In 2008 an international epilepsy awareness campaign was started that designates March 26 as Purple Day. It’s a grassroots movement that provides a framework for organizing fund-raising and educational events…should people with photosensitive epilepsy be part of it? Where do visually induced seizures fit in the epilepsy world?

Somehow, photosensitive epilepsy and other reflex epilepsies, where seizures occur in response to a specific stimulus, tend not to get much notice. This is true among clinicians and the community of people with “regular” epilepsy. I can think of several factors contributing to the marginalization of photosensitive epilepsy:

1) It starts with ambivalence among the research and clinical communities as to whether photosensitive epilepsy qualifies as “real” epilepsy. The belief that this is a rare condition has a way of relegating photosensitive epilepsy to the sidelines of epilepsy research funding, advocacy, and clinical concerns. In a future post I’ll need to further explore the issues of why the estimates of its 1 in 4,000 prevalence are tough to swallow.

“…reflex epilepsy is regarded by some as a clinical curiosity and an interest such as butterfly collecting, an attractive thing of no great consequence. We are convinced that this idea is wrong…”

— Benjamin G. Zifkin, MD, co-editor of Reflex Epilepsies and Reflex Seizures (Advances in Neurology, vol. 75), from his preface to this collection of articles for neurologists. Sounds good.

But then Zifkin continues, “Although reflex epilepsy is not common, properly studied it teaches us about the brain in general and about epilepsy in particular.” (OK, it’s not a curiosity, it’s a tool for studying the real epilepsy.)  Based on his extensive writings on the subject, I suspect Dr. Zifkin is extremely aware of the intrinsic seriousness of photosensitivity — but in the preface to his scholarly book he was appealing to the wider audience of neuroscientists who continue to view it as a trifle.

2) Another problem that creates confusion and perpetuates the ambivalence is the manner in which seizures are officially classified.

Here are two quotes from the NYU Langone Medical Center website that illustrate the essence of the confusion.

  • Epilepsy is a disorder in which a person has two or more unprovoked seizures.
  • In reflex epilepsies, seizures are triggered or evoked by specific stimuli in the environment.

How to reconcile these? What’s the difference between provoking and triggering/evoking?

When epilepsy experts describe seizures as “unprovoked,” they are referring to seizures that are not brought on by a temporary medical situation. Unprovoked seizures are an expression of a chronic, underlying neurological condition, often not identifiable, such as a lesion or a subtle malformation in brain tissue.

“In general, seizures do not indicate epilepsy if they only occur as a result of a temporary medical condition such as a high fever, low blood sugar, alcohol or drug withdrawal, or immediately following a brain concussion. Among people who experience a seizure under such circumstances, without a history of seizures at other times, there is usually no need for ongoing treatment for epilepsy, only a need to treat the underlying medical condition.”

Centers for Disease Control and Prevention (CDC) website

If the structure and biochemical environment of the brain are such that exposure to visual stimuli such as lights and patterns brings on a seizure, this is likely a permanent condition (only 25 percent of patients outgrow photosensitivity). Therefore this kind of sensitivity should be considered a form of epilepsy.  A brain tumor that causes seizures, however, is not considered to be causing epilepsy.

3) There’s enormous reluctance for clinicians to diagnose epilepsy, driven in part by backlash against more liberal diagnosing practices in the past, which may have unnecessarily exposed some patients to anti-epileptic drugs. Clinicians are typically quite strict about needing conclusive EEG evidence to assign the diagnosis.

4) Epilepsy is still a frightening word. Most clinicians avoid it, preferring to talk about seizures. So if your seizures are triggered exclusively by a video game or strobe light, why call your sensitivity to visual stimuli by such a scary name?

5) The advocacy community remains focused on severe, life-threatening forms of epilepsy. Obtaining funding to find cures for these devastating disorders is their top priority.

So where does that leave you on March 26? Are you part of the epilepsy community or not?

Would you know if you just had a seizure?

No, not necessarily. You might have no idea it happened, even. Multiple studies have shown that people often aren’t aware of their own seizures. When you consider that altered consciousness is characteristic of many seizures, it’s not so surprising. People who aren’t “all there” during the seizure may have no memory of it.

And if you have a seizure with subtle symptoms, anyone who’s with you may not realize it’s happening, either. This is a key reason many people haven’t heard much about video game seizures–many just go undetected.

The big seizures, of course, get noticed. Anyone nearby can clearly see a person who has fallen and is having convulsions. Individuals emerging from a grand mal seizure (what doctors now refer to as a tonic-clonic seizure) won’t remember the event itself, but will realize they’re not where they were before (perhaps finding themselves on the floor or in an ambulance), and may have bruises from uncontrolled movements.

Although studies show that photosensitive epilepsy can cause any type of seizure, a lot of clinicians still assume the condition produces only grand mal/tonic-clonic seizures. They may not know that partial and absence seizures are associated with photosensitivity, too. Click here for a list of some typical signs you may have had a seizure.

What are partial and absence seizures?

Partial and absence seizures can act like stealth attacks on the brain. They cause unusual behaviors and sensations, and may be followed by additional symptoms, but they often escape notice while the seizure is in progress.

Simple partial seizures produce temporary symptoms such as distorted vision or unexpected movement or tingling in one limb. Because they affect a small area of the brain, awareness and memory are not affected.

Complex partial seizures occur in 35 percent of people with seizures. Many types of behavior can take place during the seizure, depending on which parts of the brain are affected. Sometimes people may seem to continue whatever they had been doing, including talking with others. Sometimes during one of these events people are conscious enough to allow them to hear what’s going on around them–perhaps feeling everything  is happening far away–but they aren’t able to speak. Because consciousness is altered, it’s not uncommon to have either no memory of what happened during the seizure or just a vague idea. The event can be over in 30 seconds, or it may last for a few minutes.

The seizures are typically followed by headache, temporary confusion, memory loss, and/or other neurological dysfunction, as well as fatigue and “brain fog” that gradually dissipate over a period lasting up to a few days. Lingering after-effects of complex partials can easily be more of a disruption to everyday life than the seizures themselves.

Absence seizures, where a person briefly stares and “zones out,” may be very hard to notice and can be mistaken for attention problems. Learning, memory, and social interaction are often affected by the gaps resulting from interruptions in awareness, but absence seizures are not followed by after-effects.

Research shows people often don’t detect their own seizures 

In a study published in 2007 by Christian Hoppe and colleagues, 91 seizure patients were asked to record all of their seizures in a diary during the time they were being monitored on EEG. In instances where patients activated a reporting alarm just prior to or during a seizure, only two-thirds of the seizures were documented afterwards by the patients. The reliability of patient reporting was lowest when documenting complex partial seizures and seizures experienced during sleep. Of 150 complex partial seizures (verified on EEG) while subjects were awake, only 52.7 percent of the events were reported, even though subjects were periodically reminded to report all their seizures.

The study authors state, “Seizure-induced seizure unawareness is a frequent, but rather unrecognized, postictal [post-seizure] symptom particularly associated with seizures from sleeping and with CPS [complex partial seizures].”  Now consider, what are the chances that a person who has never had a seizure before, or whose seizures have never been identified, will remember after the event that something unusual happened?

In the 2004 review article “Visual Stimuli in Daily Life,” Kasteleijn-Nolst Trenité and colleagues note that during photic stimulation testing many patients do not notice brief seizures that are detected on the EEG but have no clinical signs. “The question must be raised,” they continue, “whether asymptomatic individuals might have unnoticed reflex seizures triggered by daily-life stimuli and become overtly symptomatic only when a critical age is reached (early adolescence), in combination with lifestyle-related factors.” In other words, after adolescence, photosensitive seizures that were already happening but nobody was aware of may become more visible, possibly when the nervous system is affected by additional circumstances (lack of sleep, alcohol consumption, etc.).

Need more data? In a 1996 study of 27 seizure patients by Blum and colleagues, patients were not aware of 61 percent of their seizures detected on EEG! Seven patients didn’t recall any of their seizures. Patients were questioned periodically throughout the day as to whether they’d had a seizure or if anything unusual had occurred, so the seizures would be expected to be fresh in their minds.

Can an EEG help determine whether you had a seizure? 

Let’s say something suddenly felt very weird yesterday, and you’re wondering if it was a seizure. An EEG conducted today can’t tell you if yesterday’s event was a seizure. That’s because EEGs can’t provide data on any period other than the time the electrodes are in place and recording brain activity. An initial EEG usually lasts for 20 to 30 minutes and can be thought of as an extended “snapshot” of brain wave patterns. If you have a seizure during an EEG, the EEG can confirm that it was a seizure–but only if electrodes pick up the brain waves that typically signify a seizure.

Usually at some point during the EEG you’re exposed to a strobe light to see if your brain has an abnormal response to flash. If that part of the EEG is abnormal, it can indicate that you have photosensitive epilepsy and should avoid flashing lights. The test is done in a way that doesn’t provoke an actual seizure, but it can show an abnormal “firing” of neurons that is consistent with seizures. Note that strobe lights may not create that EEG response even if a video game does–the flashing white light doesn’t make the same impact on the visual cortex that a colorful screen with lots of action. Some people don’t respond to the strobe but do have an abnormal EEG response to certain sharply defined patterns. Video games and TV may include some of these patterns, but little testing is done for pattern sensitivity in the US.

EEGs done with scalp electrodes miss a lot of seizure activity that involves a small area and/or lies deep inside the brain, far from electrodes on the surface. I’ve written about this before, but I can’t resist adding that this point was acknowledged in the above study by Blum et al. “…there are seizure types that often do not manifest on surface EEG. The most important of these is frontal lobe epilepsy, but this also occurs with complex partial seizures of temporal lobe origin.”

In fact, “it is crucial to recognize that a normal EEG does not exclude epilepsy, as around 10% of patients with epilepsy never show epileptiform discharges,” according to a 2005 paper in the Journal of Neurology, Neurosurgury & Psychiatry.

Seizures are more common and frequent than current technology and human memory can demonstrate.

Health consequences of unseen game seizures

Video game seizures EEG alterationsChild and adolescent psychiatrist Victoria Dunckley, MD has treated many young people with complex diagnoses and hard-to-treat conditions. She has seen that because electronic media overstimulate the brain, eliminating electronic screen time can be a very effective alternative or complement to psychiatric medications. Dr. Dunckley invited me onto her Psychology Today blog to write about the life-changing discovery that my daughter’s health was affected by unseen seizures from video games. Following is an excerpt:

I learned about video game seizures only after my daughter’s health, behavior, and cognitive functioning had suffered for several years. The effects of video games on her health and her daily function were pretty devastating. We didn’t fully realize how much she’d been impaired by all of the seizures until she got away from the screen. Fortunately, we were able to restore her health and greatly improve her daily life “just” by helping her eliminate video games from her life.  

Here’s a glimpse of what life was like at home when she was gaming for hours each day. Alice seemed “out of it” a lot. Sometimes at the end of the day after lots of screen time she seemed to be on autopilot, in a dazed state. At times she didn’t seem to hear us talking to her. She began showing some odd behaviors that she didn’t remember later. Alice was alarmingly volatile, abnormally fatigued, and she struggled to concentrate in class. She missed a lot of school, because many days she couldn’t be awakened until the afternoon, despite our vigorous efforts. This wasn’t ordinary sleepiness. Read the full story

When “slam dunk” EEG evidence is missing

My daughter played video games to deliberately provoke photosensitive seizures during extended, inpatient EEG monitoring. She had plenty of seizures, but they weren’t detected by the EEG sensors on her scalp. Although she was exhausted and cognitively slow from all the seizure events, the clinicians said–based entirely on the EEG data–that they saw no sign of seizures. We’ve tried this at several hospitals, always leaving with this frustrating result.

Many patients with inconclusive EEGs are dismissed by neurologists and told there’s no evidence of seizures. This is probably even more frequently the case with visually induced seizures, since most neurologists know little about them. In their training they were taught that photosensitivity is extremely rare and that photosensitive seizures are big, generalized (grand mal) episodes.

Typically, neurologists are very conservative about issuing a diagnosis of epileptic seizures (although this was not always the case). If there’s an unmistakable seizure pattern on the EEG, they feel comfortable stating that you have seizures. Without clear EEG evidence, many neurologists may not feel a seizure diagnosis is justified. If this has happened to you, you’re not alone. Although clinicians are supposed to diagnose epilepsy based on the patient’s history as well as EEG and other tests, most often EEG results are considered more indicative than all other data–even though EEG is extremely imprecise. The result is that it can take years before a patient is properly diagnosed.

Here is a sampling from various reports we received on my daughter’s video game-induced seizures and the EEG recordings done during the events:

  • “It is interesting that they almost always occur when she is alone.” [when she can concentrate fully on the game and more easily lose contact with her surroundings]
  • “Most photosensitive seizures are primary generalized with bursts of spike waves, polyspike waves, or polyspikes. It is possible for some types of visual stimuli to bring on a partial seizure. These are more rare. Even in those instances, usually there is some sort of epileptic discharge.” [Oh.]
  • “It is true that with surface EEG, we could miss partial seizures. At the same time, there are also many clinical signs that make a seizure unlikely…MRI has been normal and our clinical suspicions are quite low.” [Don’t seek and you shall not find.]
  • “The EEGs have never shown epileptiform activity, nor has there been a photosensitive response.” [See my post on testing for photosensitivity using photic stimulation]
  • “Due to the normal EEG and the precipitation of events with only limited stimuli, we feel it is unlikely that these events represent seizures.” [In other words, if only video games precipitate seizures, these can’t really be seizures.]
  • “The patient was playing a video game and then stopped…There was no obvious change in the patient’s observed behavior in that she was sitting on a stool in front of a monitor playing a game…The EEG also did not show significant change…[She stopped playing the game—isn’t this a change in behavior?]
  • “The two…events that were recorded…failed to reveal an identified behavioral change that would appear to be convulsive in nature.” [Since when are all seizures convulsive?]
  • “The patient had a few jerks of her limbs during photic stimulation, but there was no electrographic correlate.” [Hmmmmm.]
  • “There is a generalized irregular slow wave burst…at which time the patient is swaying her head to and fro while watching a video. This activity is not epileptic and most likely related to movement.” [An unsupported guess with no effort to gather more evidence. Ask the family if swaying the head to and fro is typical behavior. Or ask the patient if she recalls swaying while playing.]

Sound familiar? Anyone else want to share similar results?

Autism’s high rate of photosensitivity

Young people with autism spectrum disorders (ASD) are far more likely than the rest of the population to be photosensitive–susceptible to visually triggered seizures from flashing light, video games, and other strong visual stimuli. Results from a new study made public last week at the American Epilepsy Society annual meeting showed that fully 25 percent of those age 15 and up with ASD are photosensitive. In contrast, the prevalence of photosensitivity among typical young people is said to be 1 in 4,000 (although I believe this is an underestimate).

For some time I’ve suspected that the rate among ASD young people is elevated, and I’ve been attempting to find funding for a study that would examine young people with ASD and their risk of seizures from video games. Here are some reasons why I believe video games pose a particularly acute seizure risk to young people with autism:

  • This population develops classic epilepsy at significantly higher rates than the general population
  • Children with ASD have very high rates of sensory processing disorders, including difficulties with visual processing
  • Children with ASD tend to spend their leisure time with electronic media, and they exhibit a preference for animated material, thus they are likely to be heavy users of video games

Not only are young people with ASD at higher risk of visually induced seizures, they are also less likely to have their seizures noticed and properly identified:

  • The unusual repetitive and nonresponsive behaviors that are common in individuals with ASD can be difficult for an observer to distinguish from seizures
  • In children with ASD, impaired executive function, energy, mood, attention, and cognitive ability resulting from seizures might be masked by pre-existing chronic deficits in these functions

My guess is that photosensitivity among young people with ADHD (attention deficit hyperactivity disorder) is probably higher than average, too, because of these same factors.

Here’s why this matters so much: Although it would be difficult to change game usage habits, parents of children with autism should exercise particular caution in allowing exposure to visually overstimulating images. Reducing or eliminating visually induced seizures could result in noticeable improvements in their children’s daily functioning. The last thing these vulnerable kids need is added interference, due to seizures, with cognitive and behavioral flexibility.

The study announced last week is the first to look at the photosensitivity rate in autism. It was performed at Children’s Hospital in Boston, where researchers investigated the EEG histories of children diagnosed with ASD. More research is certainly warranted, particularly since the photosensitivity assessments were done the usual way, using photic stimulation with a strobe light. Photic stimulation may show a person’s vulnerability to seizures from a strobe light, but a strobe does not recreate the experience of exposure to a video game screen. Some individuals who do not demonstrate an EEG response to the strobe may nevertheless experience seizures provoked by video games.

NOTE:  Read more on autism and seizures from sensory overload in this post from 2012. You may also want to read this post on ADHD in connection with and video games and seizures.

Frequent seizures can blunt learning ability

Cognitive decline can sneak in after repeated unseen seizures

Parents who observe a child’s grades slipping may be quick to blame video game activity, reasoning that too many hours spent on video games has meant not enough time is being spent on homework and studying. The cause-and-effect relationship might not be that simple, though. Declining school performance among frequent, longtime gamers could be the result of reduced cognitive ability caused by undetected screen-induced seizures.

People who don’t experience recognizable seizures from video games may nonetheless  have what are called subclinical seizures – events that qualify on EEG as seizures but don’t cause noticeable symptoms. (Subclinical seizures can happen to people who sometimes have very obvious seizures, too.) How would you know about seizures that can’t be seen and that the child is not aware of? You probably wouldn’t, unless you had EEG testing done that showed abnormal response to photic stimulation.

Over time, if seizures continued to happen fairly frequently, you might notice some memory problems or less alertness, which also could be due to stress or depression or many other causes. Research on the effects of short, nonconvulsive seizures that have no symptoms suggests that after many seizures over a period of time, there’s a cumulative impairment of the ability to acquire and retain information. “The clinical relevance of this…is that early detection of the cognitive impact of seizure-related activity and subsequent treatment may prevent a detrimental impact on cognitive and educational development,” according to a 2004 study in the journal Epilepsia.

The same authors note in an earlier paper that the cognitive functions most affected by frequent, hard-to-detect seizures are short-term memory and alertness. “Often these [nonconvulsive] seizures present as behavior fluctuations or attentional disorders and can therefore persist during a longer period.” This means that individuals with existing behavioral issues or attention problems are less likely to notice these changes or to have them noticed by others.

People with short, nonconvulsive seizures who remain untreated for a long time demonstrate lower IQ scores. Performance on IQ tests and in daily life is generally reported to improve when seizures are brought under control. “In children with difficult-to-detect seizures, the authors reported “sudden and unanticipated decline of school performance as the first symptom, again as a result of the accumulating effect of such seizures on cognitive function.”

In short, we know from research studies that:

Put them all together, and it’s clear all video games need to be made seizure-safe, because seizures can happen to anyone, and, undetected, they can continue to occur and impair functioning for years. Parents, legislators, regulatory agencies, game developers, and the entertainment software industry have been standing by and allowing unknown numbers of children to lose strength in some of their core mental abilities, most likely for years at a time. The UK, which requires broadcast TV to be seizure-safe, is moving in the direction of seizure-safe games. How long will it take and how many lives will be diminished before stakeholders everywhere  pay attention to this public health problem?