What is Photosensitive Epilepsy?
Photosensitive epilepsy is a medical condition in which epilepsy attacks are triggered by flashing or flickering of light. This type of epilepsy is common in children and decreases with age. The most common triggers of Photosensitive epilepsy are video games and television, but natural light can also trigger some.(1) Some people get epileptic seizures by looking at the sunlight passing through the Venetian blinds or through the leaves of the tree. Some get seizures by contrasting and changing color.
According to the Epilepsy Foundation, those with photosensitive experience their first epileptic seizure before the age of 20.(2)
About 59-75 percent of people experiencing photosensitive epilepsy are females. But, it is believed that photosensitive epilepsy occurs more in boys as boys play video games more.(3)
Photosensitive epilepsy can trigger different types of seizures, which include:
Photosensitive epilepsy is found to affect children more. Studies found that 30-90% of people with juvenile myoclonic epilepsy have photosensitive epilepsy.(4)
It is known to affect people of all ethnic groups. Studies suggest a higher rate of photosensitive epilepsy amongst people of European and Middle Eastern groups and lower rates amongst Africans.(5)
Causes and Triggers of Photosensitive Epilepsy
The exact cause of photosensitive epilepsy is unknown. Genetics are believed to play a role in its development. People who have a unique variation of the CHD2 gene are known to have photosensitive epilepsy.
Research indicates that changes in connectivity between different areas of the brain lead to photosensitive epilepsy.(4)
Studies suggest that gamma waves that oscillate 30-80 times in the visual cortex generate seizures in people.(6)
Triggers of Photosensitive Epilepsy
The two most common triggers of photosensitive epilepsy are watching television and playing video games.
Bright light sources can also lead to the development of seizures.
Lights flashing 15-25 times per second can lead to seizures.(1) Also, red light is more likely to cause epilepsy than blue light.
Following are the common triggers of photosensitive epilepsy:
- Strobe light
- Highly contrasting visual patterns
- Video games with rapid light flashes
- Flashing lights from emergency vehicles
- Sunlight reflecting from water or flickering through the trees
- The flickering light of television or computer
Symptoms of Photosensitive Epilepsy
The symptoms of photosensitive epilepsy depend on the type of seizure. The symptoms include:
- Changes in vision
- Clenching of teeth
- Strange taste in the mouth
- Rapid eye movements
- Muscle spasms that are uncontrollable
- Loss of bladder and bowel control
- Loss of consciousness
- Jerky movements of arms and legs
Diagnosis and Treatment of Photosensitive Epilepsy
To diagnose seizures, a neurological examination is done by the doctor, in which reflex, muscle strength, and posture are checked.
Electroencephalogram is used in the diagnostic process, as it records the electrical activity of the brain and unusual patterns of electrical activity that might be a sign of epilepsy.
Treatment of photosensitive epilepsy is done with seizure medications. A doctor should be consulted for the appropriate medication and dosage.
How to Prevent Photosensitive Epilepsy?
Those sensitive to flashing and flickering light can be able to prevent seizure by:
- Using LCD screens
- Watching television in a well-lit room
- Avoiding exposure to flashing lights
- Avoiding watching television for long periods of time
- Avoiding playing video games
- Sitting away from the television
- Avoiding strobe lights
- Taking breaking while working on a computer
If someone develops a seizure for the first time, it is important to consult a doctor, as he can help determine the cause and advise a solution accordingly.
If the seizure extends for longer than 3 minutes or a person does not wake up after the seizure, call emergency service.
Photosensitive seizures can be easily treated by medication and by avoiding triggers. Most people with photosensitive seizures stop having them after 30 years of age. Taking proper medication and precautions can help prevent them early.