Photosensitive epilepsy
Last checked 20/06/2008
Introduction
We would like to thank Professor G F A Harding, formerly of Aston University, England and Professor Stefano Seri, of Aston University and the Birmingham Children’s Hospital NHS Foundation for their help and support in producing this information.
Photosensitive epilepsy is the name given to epilepsy in which all, or almost all, seizures are provoked by flashing or flickering light, or some shapes or patterns. 
Both natural and artificial light may trigger seizures. Various types of seizure may be triggered by flickering light.
Many people think that everybody with epilepsy is photosensitive, but in fact only five in every hundred people with epilepsy are. Photosensitive epilepsy usually begins before the age of 20 years, although it is most common between the ages of seven and 19. Photosensitivity tends to affect girls more than boys. There is also evidence that photosensitive epilepsy can be passed on through the genes.
Diagnosing photosensitive epilepsy
One investigation that is carried out to diagnose epilepsy is an [electroencephalogram], or EEG. The EEG records brainwave patterns from the continuous tiny electrical signals coming from the brain. During one part of the EEG, you are asked to look at flashing lights, to see if this triggers epileptic activity in the brain. If it does, then this may indicate that you have photosensitive epilepsy.
Hertz
The word hertz (Hz) refers to how often something happens in a given time. In photosensitive epilepsy, hertz (Hz) refers to the number of flashes or flickers a second. When talking about televisions or computer screens, hertz refers to the rate the scanning lines ‘refresh’ themselves.
Most people with photosensitive epilepsy are sensitive to 16-25 Hz, although some people may be sensitive to rates as low as 3 Hz and as high as 60 Hz.
Information updated June 2007
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Comments
My son suffers from marked photosensitivity and has to be constantly aware of his surroundings. Last year an incident happened which we hadn't thought of even after 5 years. Our bathroom window faces our road and has a frosted pane of glass with leaf patterns on it. A lorry with yellow flashing lights pulled into our road and was stationary outside our house. The flashing lights magnified in each of the leaf patterns making it look like a mass of flashing images. Unfortunately, my son was in the bath at the time and ended up having a seizure. We now pull down the blind each time just in case this happens again.
I was diagnosed with Photosensitive epilepsy about a little less than a year ago. I am 16 years old and I am confused. My neurologist got mad at me one time when I couldn't follow what he was saying, so why waste his time? I was just wondering...I have "seziures" but they aren't really, there wierd because all I do is faint. I faint, tense up, get shaky when I come to and then move on. Is it really seziures I'm having? I don't really think so, I pictured seziures as a spastic motion. I've seen one before, and everyone I know says I don't do that, they say I just tense up. So what's the deal?
Dear Helena,
I've got photosensitive epilepsy too, and actually your symptoms don't sound so unusual. My seizures include seeing a special multicoloured circle that only I can see (an aura) and then I black out. When I'm blacked out apparently I do all sorts of things: foam at the mouth, tense up, jerk in a spastic motion, grind my teeth, bite my tongue etc, and wake up feeling totally exhausted. Some people who have absence seizures just zone out for a short time (like going into a temporary coma) and then come back around and keep going on with what they were doing. I think what you are picturing is the "classic" seizures, which are common, (and usually the ones shown on TV) but they are certainly not the only type, and so I would encourage you not to feel bad just because your symptoms don't match those you've seen elsewhere. Either way, I think its important to persist in talking to your specialist, so you can understand your condition. If your current neurologist isn't helping you, don't hesitate to ask him more questions to clarify things, or even look for a new one! After all it is really important you understand what's happening and it's your neurologist's job to explain that to you!
best wishes!
If you have photosensitive epilepsy. Wear sunglasses. Haven't had a seizure since.
I find that wearing a cap helps a little in shutting out excessive glare/sunlight when out and about, and in busy places. The worst nightmare though is light shining off water if you have this type of epilepsy.
Hi,
I'm new to this form of condition. My 6 year old son (Reinardt) has been diagnosed with PSE last week and I need as much information possible. It all started about 3 months ago when we noticed that he rotates his eyes when exposed to the sun. The first EEG was negative. When his condition became worse I decided to take him for a second opinion. Another EEG was done. Within a few minutes he had his first seizure and then another when he was exposed to the light. It's been 19 months since his recovery from Guillian Barrey Syndrome (a very traumatic immune illeness - was paralized from head to toe). This was a blow for us, because of the traumatic ordeal and now we need to get over this obsticle. Any suggestions on how we can make life easier for my little boy?
Greetings from Jane (Reinardt's mom in South Africa)
Hi Jane
Like your son (Reinardt) I too was diagnosed with PSE when I was 6 years old. Next month I'll be 27. I've lived in the UK for the last 6 years, but I'm from South Africa and always will be South African.
This website and others have so much information, it has more info than than ever before. Also you have the added bonus that these days the internet is freely available. When I was 6 and my mom was looking for information, she was truly alone in her search.
The only thing I can give you, Is my life story(so far). This I think is just as valuable as the information that you'll find on websites, as it a real life story of the ups and downs of living PSE. The learning to mould you life around PSE and not let PSE mould itself around your life.
Hope you and Reinardt are well.
Kind Regards
Ryan
I and the consultants that I am seeing in the UK are unsure whether I have epilepsy or not. I have seizures but don't lose consciousness. I am sensitive to strobing lights which set me off. I was in the cinema last weekend and there was a car chase at night with car headlights creating a strobing effect. I therefore had a seizure in the cinema. This has happened before and also light flickering through trees on a sunny day and strobing effects on TV such as "flashback" scenes. Is this symptomatic of "classic" epilepsy? Can anyone offer any advise?
Hello all,
I don't suffer myself, but my 48 yr old partner does. The main trigger for her photo reaction is flash photography, but only that found on digital cameras. (Xenon I believe). What does seem strange is that it is not only "live" flashes, but also through TV. Being a Formula 1 follower, the onset of night races is very bad news because of the increased intensity of the cameras, and a recent visit to the Louvre to see the Mona Lisa was a disaster now that they allow photography. It appears from what I've read so far that different people have different triggers. Has anyone seen any results/research for filtering glasses?
Sorry, I think it was Helena (don't have the original posts in view). If your consultant really accused you of wasting his/her time, and you ARE suffering blackouts after photo exposure (or anything else is triggering such a thing), you must demand to see someone else. It is not acceptable if you are having this problem for someone who is supposed to be a professional to dismiss your real problem. If the person who you are seeing cannot identify the circumstances THEY should refer you to someone else for a second opinion.
My partner also suffers from full on epileptic seizures, which are brought on by other things. Sometimes the photo triggers lead on to a full seizure, depending on the circumstances (tiredness/stress/being rather drunk!! TEE HEE).
I wish you all the very best of luck with your varied circumstances. Whatever, please don't let it limit you more than it has to. We have found that the more people who are aware of the situation, the more normal life can be. Everyone round here knows that my dearly beloved has this problem, and know what to do if she throws one. That is a much safer way to be, and gives more freedom to do whatever.
All the best
Brendan
I was diagnosed with PSE In Jan 2001 when I was 21 and at university living 350 miles away from my family. I had to go through a brain scan and an EEG before I was diagnosed: no one told me I needed to take anyone with me, or that it would be best to take the person who saw me have the seizure. The procedures weren't particularly explained to me and I wasn't offered transport or a place to talk about this bewildering and scary development.
When I had completed both the scan and EEG the consultant at the hospital only had the scan result and wanted to send me away saying my scan was clear so I was OK. It was only when I pressed for him to ring to get the EEG results that he did this, and then stated that I did in fact have front cortal epilepsy with a photosensitive component. He didn't really explain what this meant, whether I would only experience a seizure as a result of stimulus or whether I could one day just begin to have seizures for no obvious reason. I spent about 10 minutes in total with the consultant and he sent me away with no follow-up appointment and very little advice.
Since this time I have had no further tonic clonic seizures and a handful of partial seizures; I think this is largely due to the fact that I now watch TV less, go clubbing less and avoid disco balls/flashing lights as much as possible.
I feel that the majority of my friends and family don't understand just how massively being diagnosed with epilepsy has effected me. Because I don't have frequent seizures and I'm not on any medication, it feels like people feel I'm being overly cautious when I explain I can't go into a bar because of the lighting, or when I have to leave a theatre because of the strobing. People always say "well you haven't had a fit for a while now so you're OK aren't you?"; what they don't see are the hundreds of little adjustments I have to make to my daily life to try and avoid the stimulus that could bring on a seizure again. It's not that I worry about it every second, but I have to constantly be aware of things that others don't have to think about like the way that light is being flickered through trees, the flashing lights of workman relaying the pavement on the motorway, emergency vehicles stopping on the road outside my workplace, TV programmes with rotating patterns or flash photography.
I have had no further support from the NHS; I understand very little about my condition other than what I've read on websites (which in itself can be confusing) and I feel that no-one else understands how PSE has changed my life. I wonder what support I should be getting and also where I can go to talk about how I feel. PSE influences all aspects of my life, from the kind of places I can go with my friends, the TV programmes I can watch, swimming alone etc. The consultant who initially diagnosed me gave me a confusing list of stimulus to avoid and I feel I've just been left to try and muddle on with no support. My experience makes me wonder how many people who experience PSE are just given the same confusing list of stimulus to avoid and then sent out to monitor and deal with the condition by themselves. My family were never offered any support, not even a leaflet on first aid and I have had to have many difficult conversations with people trying to explain what they should do if I have a seizure.
Perhaps if the consultants' ever experienced seizures themselves they would spend more time offering support - because they are both terrifying, ailenating and challenging. Dealing with them alone is a very difficult and tiring job; I always have to be on my guard, making sure I am aware of my environment, looking for potential lights, monitoring how lights are making me feel and taking a calculated risk that I'll be OK. Even if I'm sitting at a bus stop and a council vehicle with a flashing light stops near me I feel nervous, worried and this panicky feeling comes on frequently because it is so hard, in this age of technology and ever increasing light shows, to avoid flashing lights and projected patterns. I never know for sure how a situation will pan out and it is this unknown element that is the scariest of all. While I may not be experiencing seizures on a daily or even monthly basis I live with PSE every day of my life.