Abstract
In this study, we estimated the propagation configuration of epileptiform discharges in the ictal period from electrocorticogram of intractable epilepsy. We calculated the average value of the top 1% of the maximum cross correlation values of each channel-to-channel of the electrocorticogram. In the early stages of seizure, the value was rapidly rising when epileptiform discharges propagated throughout the brain. However, it was rapidly reduced in about 10 seconds despite the epileptiform activities continued, that is, the epileptiform activities were independently going on in each part of the brain. In the seizure termination, it increased again. The result indicates that each part of the brain synchronized towards the seizure termination. The results of the connectivity analysis show that the propagation configuration differed greatly between the onset of seizure and at the seizure termination.
