Purpose: To disclose possible epileptologic differences between photosensitive and nonphotosensitive patients with seizures induced by electronic screen games (ESGs).
Methods: In patients with ESG-induced seizures who showed photo- and pattern sensitivity, magnetoencephalography (MEG) and EEG were performed simultaneously during ESG play, and equivalent current dipoles (ECDs) of the MEG spikes were estimated. In patients without ESG-induced seizures, who were surgical candidates, the intracranial EEG was analyzed for changes in epileptiform spike frequency.
Results: Fifteen of 29 patients were photo- or pattern sensitive, and they had a posterior predominance of ECDs of the MEG spikes. In contrast, nonphotosensitive patients had an anterior predominance of ECDs. Other seizure-precipitating factors in the nonphotosensitive patients included hand manipulation or spatial processing. In patients without a history of ESG-induced seizures who underwent intracranial EEG monitoring for surgical evaluation, ESG playing induced changes in spike frequency in the supplementary motor area, perisylvian region, and medial temporal lobe.
Conclusions: In photosensitive patients, interictal MEG spikes arise predominantly from the posterior region of the brain. In nonphotosensitive patients, epileptiform spikes tend to originate in the anterior part of the brain. Thus factors involving functions of the anterior part of the brain other than photo- or pattern sensitivity may play a role in the induction of seizures during ESG play. Furthermore, the changes in spike frequency in specific brain areas may correspond to their involvement in praxic activity and emotional changes during ESG play. A chance occurrence of seizures during ESG play also was observed.