Objective: Photosensitive epilepsy (PSE) is the most common form of reflex epilepsy. Usually, to find out whether a patient is sensitive, he/she is stimulated visually with, e.g. a stroboscopic light stimulus at variable frequency and intensity until a photo paroxysmal response (PPR) occurs. The research described in this work aims to find whether photosensitivity can be detected without provoking a PPR. Methods: Twenty-two subjects, 15 with known photosensitivity, were stimulated with visual stimuli that did not provoke a PPR. Using an "evoked response representation", 18 features were analytically derived from EEG signals. Single- and multi-feature classification paradigms were applied to extract those features that separate best subjects with PSE from controls. Results: Two variables in the "evoked response representation", a frequency term and a goodness of fit term to a particular template, appeared to be best suited to make a prediction about the photosensitivity of a subject. Conclusions: Evoked responses appear to carry information about potential PSE. Significance: This result can be useful for screening patients for photosensitivity and it may also help to assess in a quantitative way the effectiveness of medical therapy.

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doi.org/10.1016/j.clinph.2007.11.177, hdl.handle.net/1765/30230
Clinical Neurophysiology
Erasmus MC: University Medical Center Rotterdam

Vermeulen, J., Kalitzin, S., Parra, J., Dekker, E., Vossepoel, A. M., & da Silva, F. L. (2008). Non-provocative diagnostics of photosensitivity using visual evoked potentials. Clinical Neurophysiology, 119(4), 842–852. doi:10.1016/j.clinph.2007.11.177