The epilepsy photosensitivity model includes study participants who have reproducible generalized epileptiform discharges on electroencephalogram stimulated by flashing lights within a range of frequencies called a photoparoxysmal
An EEG demonstrated a photoparoxysmal
response at 9, 15, 18, and 27 Hz.
Stephani, "Altered cortical visual processing in individuals with a spreading photoparoxysmal EEG response," European Journal of Neuroscience, vol.
Siniatchkin, "Representation and propagation of epileptic activity in absences and generalized photoparoxysmal responses," Human Brain Mapping, vol.
Photoparoxysmal response was seen in 40% of patients.
Photoparoxysmal response (PPR) is defined as the occurrence of spikes, spike waves, poly-spike waves, or repetitive spikes in response to intermittent photic stimulation, which was observed in 30 patients (34.5%), while focal EEG abnormalities were recorded in 25 of our patients (28.7%).
Pathological findings of EEG were classified as follows: (a) epileptiform discharges (focal spikes multifocal spikes generalised spike waves spike-wave complexes or presence of photoparoxysmal
responses); (b) paroxysmal EEG abnormalities; and (c) background slowing (focal or diffuse).
A low prevalence of photoparoxysmal
response has been observed in African and Asian patients.4
A photoparoxysmal response (PPR) occurred in 13 children (11%).
Major Finding: Eleven percent of the children with both autism and epilepsy experienced a photoparoxysmal response.
The different patterns of the photoparoxysmal
response- a genetic study.
Eligible subjects are those patients with demonstrated epileptiform activity by electroencephalogram (EEG) in response to photic stimulation (also called a "photoparoxysmal
response to light") and represent a small subset of all patients with epilepsy.