Colour and photosensitive epilepsy.

In this study we relate our experience in 7 cases of photosensitive epilepsy and the effect of different types of filters upon the photoconvulsive response (PR). The study was performed with an 8 channels electroencephalograph and the patients were stimulated with a Joule lamp (1 c/sec-30 c/sec). Red, yellow, blue and green cellophane paper filters were used. The EEG response presented bilateral spikes or polyspikes and slow wave paroxysmal discharges. In the presence of a blue filter, the PR appeared later: an average of 6 seconds of closing the eyes and the response had a lower amplitude. In addition the PR did not appear or it was blocked when we used a double blue filter. These results support the role of the retina in the genesis of the PR. We suggest that the blue filter allows a small percentage of light transmission and under these conditions the electrical events that follow light stimulation do not occur.

Colour and photosensitive epilepsy.

In this study we relate our experience in 7 cases of photosensitive epilepsy and the effect of different types of filters upon the photoconvulsive response (PR). The study was performed with an 8 channels electroencephalograph and the patients were stimulated with a Joule lamp (1 c/sec-30 c/sec). Red, yellow, blue and green cellophane paper filters were used. The EEG response presented bilateral spikes or polyspikes and slow wave paroxysmal discharges. In the presence of a blue filter, the PR appeared later: an average of 6 seconds of closing the eyes and the response had a lower amplitude. In addition the PR did not appear or it was blocked when we used a double blue filter. These results support the role of the retina in the genesis of the PR. We suggest that the blue filter allows a small percentage of light transmission and under these conditions the electrical events that follow light stimulation do not occur.