Seizure Disabilities

Demographics

50 million people globally have epilepsy, of which 3% have the photosensitive type.

Medical Details

What is a Seizure?

According to Mayo Clinic, a linked BoK source, a seizure is a sudden burst of electrical activity in the brain that causes changes in behaviour, movements, feelings and levels of consciousness.

Before a seizure, some people experience an 'aura' or hard-to-describe sense that a seizure may happen. Post-seizure, a person may feel confused, dizzy, anxious and frustrated. Recovering from a seizure can take minutes to hours.

Some seizures happen in just one area of the brain. These cause changes in awareness (as if in a dream-like state) or change how both mental and physical phenomena are experienced (eg. changes in taste, emotional changes). People experiencing these 'focal seizures' may exhibit bizarre or repetitive physical movement patterns.

Seizures that involve all areas of the brain are more easily identifiable by their physical symptoms-- causing sudden muscle stiffness, loss of muscle use, jerking or twitching muscle movements, or passing out.

Another form of these full-brain seizures common in children is an 'absence seizure,' a short seizure that causes a child to temporarily space out for 5-10 seconds. These come in clusters, and can happen up to hundreds of times per day.

According to Merck Manual, a linked BoK source, non-epileptic seizures may be triggered by infection, head injury, or reaction to a medication. A person can also experience a 'psychogenic nonepileptic seizure,' or 'pseudoseizure' which feels very similar to a seizure, but is caused by mental disorders and not strange electrical activity in the brain.

Epilepsy

According to the WHO's page on epilepsy, a linked BoK source, epilepsy is a diagnosis given to people who have two or more unprovoked seizures. A one-off seizure doesn't count. They explain that epilepsy can come from many different disease mechanisms. For example, meningitis can infectiously cause epilepsy. Brain malformation can genetically cause epilepsy. Brain damage from head trauma can structurally cause epilepsy. It may also stem from metabolic, immune, or unknown causes. It is generally treated using antiseizure medications.

Merck Manual also reports that there are different kinds of epilepsy sub-types that can be diagnosed, such as Dravet syndrome, Nonconvulsive status epilepticus.

According to Epilepsy Action, a linked BoK source, Photosensitive epilepsy is an especially rare type of epilepsy where seizures are caused by photosensitive triggers. People with photosensitive epilepsy will have different degrees of sensitivity to photosensitive triggers. While flashing lights are the most well-known example of a photosensitive trigger, photosensitive triggers may also be things like:

• an animated gif
• moving escalators
• black and white stripes, and other high-contrast patterns
• rotating blades
• sunlight, through slatted blinds
• sunlight, through moving leaves

Flicker rates of 16 to 25 times per second are the most likely to be photosensitive triggers. However, it really does vary between individuals. Additionally, people with photosensitive epilepsy will often also have seizures that are not caused by photosensitive triggers.

Accommodations

Out and About

People with epilepsy have to be especially careful when participating in activities where a loss of consciousness could cause serious harm. A person with epilepsy might swim only when they have a lifejacket on, or might request supervision when using power tools.

People with epilepsy will have differing comfort levels. Some will be very comfortable in recognizing the aura of an oncoming seizure and working through seizures independently. For other people, seizures may come on less predictably.

On the Web

People with photosensitive epilepsy in particular must engage quite carefully with the web. There are many websites that do not provide controls to stop or turn off video and animations. Four WCAG Criteria are in place to support people with seizures: Pause, Stop, Hide and Three Flashes or Below Threshold are considered essential, minimum Level A criteria. They are also two of the four 'non-interference' criteria, as failure to meet with them can interfere with any use of the page. Three Flashes and Animation from Interactions are considered advanced, Level AAA criteria.

Assistive Technology

Epilepsy Australia, a linked BoK Source, shares some technology that a person with a seizure disability might use to help monitor and reduce risk.

Seizure detection

There are smart-watches that are specifically built to detect seizures, and basic electrical heart sensor functionality is built into Apple Watches. Specific technology might be warranted for specific types of seizures. For example, a headband that detects absence seizures, or an under-the-mattress monitor for convulsive seizures.

Injury prevention

Helmets and harnesses may be used by people who have drop-attacks to lessen the amount of bruising or injury caused by sudden and unexpected falls.

Alert wearables

In the case of a seizure, medical jewelry with notification features may be used to call a caregiver or paramedical support.

Photosensitive reduction

Includes things like flicker-free monitors, flare guards, and non-glare glasses.