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Photosensitive Epilepsy

     

Among all people who have been diagnosed as epileptic, between three and five percent are known to be of the Photosensitive Epilepsy. Persons with PSE experience epileptiform seizures upon exposure to certain visual stimuli.

The exact nature of the stimulus or stimuli that triggers the seizures varies from one patient to another, as does the nature and severity of the resulting seizures (ranging from brief absence seizures to full tonic-clonic seizures). Many PSE patients experience an “aura” or feel odd sensations before the seizure occurs, and this can serve as a warning to a patient to move away from the trigger stimulus.

Symptoms of Photosensitive Epilepsy

Seizures cause different physical effects depending on which parts of the brain are involved and how far the signals fan out. Some people have violent seizures that knock them to the floor unconscious and twitching. Others go through less severe seizures that make them blank for few seconds or more. Some mild seizures pass so quickly that it seems the person is just daydreaming.

The onset of photosensitive epilepsy in an individual occurs typically around the time of puberty; in the age group 7 to 20 years the condition is five times as common as in the general population. Three quarters of patients remain photosensitive for life.

Cure and Treatment of Photosensitive Epilepsy

No cure is available for PSE, although the sensitivity of some patients may diminish over time. Medical treatment is available to reduce sensitivity, with sodium valproate being commonly prescribed. These actions together can reduce the risk of seizures to almost zero for many PSE patients. 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.

The most common environmental hazards are natural sunlight, artificial lights (especially flickering, malfunctioning fluorescent lighting), cathode ray tube television screens and patterns from Venetian blinds, rolling escalators, striped walls and striped clothing. And although there is no epidemiological data to support this statement, the most frequent triggers of photically-induced seizures nowadays are probably video games. This is not surprising because video games are in the hands of the most susceptible population, and also because video games contain strong visual stimuli to make them more attractive.