Health and Wellness Blog

Approximately 1.3% of Canadians have epilepsy and about 6% of people with epilepsy experience reflex seizures.  Reflex epilepsy is a condition in which seizures are triggered by specific stimuli, such as flashing or flickering lights, eating, sudden noises, music, reading, or immersion in hot water. (source)

If you think you have reflex epilepsy…

Keep a record of:

• what you are doing when you have the seizures
• whether the seizures occur under the same circumstances
• what you think may have triggered them.

This will help your doctor make a diagnosis.  You will probably be given an EEG.  During the EEG, you can be tested with the possible stimulus to confirm whether that trigger causes you seizures. (source)

What causes reflex epilepsy? (source)

A specific seizure stimulus excites neurons in a sensitive, seizure-prone part of the brain and causes a seizure.  Since this particular sensitive area of the brain is different for each person, no two people have exactly the same seizure stimuli.

Different types and forms of reflex epilepsy can have different causes.  Some types may be caused by focal brain abnormalities and some may have a genetic component.

What are the various types of reflex epilepsy?

There are many types and forms of reflex epilepsy.

Visual sensitive epilepsy

This type of reflex epilepsy can be caused by flickering or flashing lights, specific visual patterns, blinking, or other visual stimuli.

Photosensitive epilepsy, the most common reflex epilepsy, has a genetic component.  Seizures may be triggered by light filtering through trees or even through Venetian blinds.  Flickering lights from television screen, computer monitors, or video games can also cause seizures.  It is interesting to note that the slower the flicker, the more likely a person with photosensitive epilepsy will have a seizure. (source)

Besides flickering of flashing lights, particular visual patterns (also called pattern-sensitive epilepsies) can'trigger seizures.  Stripes, spiral patterns, bars, moving patterns like escalators, patterns with a high “light-dark contrast” or with certain colours especially red, can cause seizures. (source)

Seizures triggered by complex actions or mental processes (source)

Primary reading epilepsy often runs in families.  Seizures are caused only by reading and are more likely to occur the longer the person reads or the more difficult the material being read is.

Eating epilepsy has various stimuli.  For some people with eating epilepsy, just looking at food or smelling it may cause seizures.  Other people may experience seizures when they begin to eat.

Toothbrushing-induced epilepsy is rare.  It is thought that the rhythm involved in brushing teeth is probably responsible for the seizures.

Language-induced epilepsy has several stimuli.  Seizures can be caused by writing, singing, reciting, or even typing. (source)

Hearing-induced epilepsies

Musicogenic epilepsy involves music as a stimulus.  This type of reflex epilepsy is triggered by certain types of music, particular tones, or frequencies of pitch.  Sometimes even the memory of a particular piece of music can cause a seizure. (source)

Startle epilepsy is a form of reflex epilepsy in which seizures are caused by a person being startled, usually by a sudden loud noise.  Developmental delay and hemiparesis are often seen in people with startle epilepsy.

Telephone epilepsy is not common.  Seizures occur only when a person with telephone epilepsy answers the telephone.  Hearing the voice of someone calling seems to be the main trigger. (source)

There are still other forms of reflex epilepsy such as those triggered by walking, hot water immersion, and touching.  (source)

If I have reflex epilepsy, what can I do to help myself?

The most important thing to do is to avoid the things that trigger your seizures or at least minimize your exposure to them.  If you have photosensitive epilepsy, for example, try the following: (source)

• When watching television, do not sit within 2.5 metres of it, and make sure the room is well lit.
• If working at a computer, try to reduce the glare from the screen, make sure the monitor screen refreshes at 60 Hz, and sit 30 cm away from the screen.
• When you are outside or inside and near flickering or flashing lights, wear blue polarized sunglasses.
• Cover one eye when exposed to flickering lights.

Your doctor may also recommend your taking sodium valproate, the drug of choice for photosensitive seizures. (source)

Depending upon the cause of reflex epilepsy and how easily the seizures are controlled, people can live quite normal lives.  In the case of children with photosensitive epilepsy, about one quarter of them will outgrow it by the time they are in their twenties. (source)

 Further reading

Hospital for Sick Children. AboutKids Health. Reflex epilepsy. (2006)

Epilepsy Toronto. Photosensitivity (fact sheet).

Epilepsy Ontario. Musicogenic seizures. 

Epilepsy Ontario Startle epilepsy. (2006)

Epilepsy Ontario Telephone-induced seizures. (2004)

Epilepsy Ontario Visual reflex seizures induced by complex stimuli. (January 2004)

Epilepsy Canada. Photosensitive seizures. (2003)

eMedicine. Reflex Epilepsy. (August 27, 2007)

epilepsy.com. Reflex epilepsies. (2004)

epilepsy.com Spotlight Newsletter. Photosensitive seizures. (February 2009)

Epilepsy Foundation. (U.S.). Reflex epilepsy

Epilepsy Foundation. (U.S.).  Photosensitivity and seizures.