Photosensitive Epilepsy
Many thanks to Professors G Harding (Aston University, England) and S Seri for providing the information on which the following is based.
Introduction
It is often assumed that everybody with epilepsy is photosensitive, but only around five per cent of people with epilepsy are. Photosensitive epilepsy is the name given to a form of epilepsy in which seizures are triggered by flickering or flashing light.
Both natural and artificial light sources can cause flickering which might be a problem for people with photosensitive epilepsy. For example, sunlight reflected off wet surfaces or through leaves of trees, flashing lights in discos and the flickering of faulty fluorescent lighting may also trigger seizures. However the commonest trigger for people with photosensitive epilepsy appears to be television.
Most people with photosensitive epilepsy are sensitive to flickering around 16-25Hz, although some people may be sensitive to rates as low as 3Hz and as high as 60Hz.
People with photosensitive epilepsy usually develop the condition before the age of 20, with it being most common between the ages of nine and 15. More females than males seem to have photosensitive epilepsy. There is also evidence of a genetic factor in this condition.
Various types of seizure may be triggered by flickering light, but a tonic-clonic seizure is certainly the most frequent type induced by television, sometimes beginning with myoclonic jerking (brief jerking of the limbs).
More specific information about photosensitive epilepsy can be obtained from Epilepsy Action by using the Email Helpline or if you live in the UK, by phoning the freephone Helpline on 0808 800 5050
Information updated 28 October 2005
Information update
http://www.hardingfpa.tv/index.html
Introduction
It is often assumed that everybody with epilepsy is photosensitive, but only around five per cent of people with epilepsy are. Photosensitive epilepsy is the name given to a form of epilepsy in which seizures are triggered by flickering or flashing light.
Both natural and artificial light sources can cause flickering which might be a problem for people with photosensitive epilepsy. For example, sunlight reflected off wet surfaces or through leaves of trees, flashing lights in discos and the flickering of faulty fluorescent lighting may also trigger seizures. However the commonest trigger for people with photosensitive epilepsy appears to be television.
Most people with photosensitive epilepsy are sensitive to flickering around 16-25Hz, although some people may be sensitive to rates as low as 3Hz and as high as 60Hz.
People with photosensitive epilepsy usually develop the condition before the age of 20, with it being most common between the ages of nine and 15. More females than males seem to have photosensitive epilepsy. There is also evidence of a genetic factor in this condition.
Various types of seizure may be triggered by flickering light, but a tonic-clonic seizure is certainly the most frequent type induced by television, sometimes beginning with myoclonic jerking (brief jerking of the limbs).
More specific information about photosensitive epilepsy can be obtained from Epilepsy Action by using the Email Helpline or if you live in the UK, by phoning the freephone Helpline on 0808 800 5050
Information updated 28 October 2005
Information update
http://www.hardingfpa.tv/index.html
posted by Marilyn at 11:18 AM
