ij] (t) the vector that has components the spike synchronization values within a preictal window [w.
Previous studies on prediction of epileptic seizures have revealed the existence of a preictal period where the dynamics of different brain sites become entrained (synchronized).
Crandall, "Temporo-spatial patterns of preictal spike activity in human temporal lobe epilepsy," Electroencephalogr.
Also, spatiotemporal changes in preictal spike activity in human temporal lobe epilepsy  revealed that the degree of bilateral interdependence in medial temporal lobe spike activity increased prior to onset of a seizure, thus indicating that spikes may herald the interictal to ictal transition.
For both patients, increased synchronization in the preictal and desynchronization in the postictal periods can be observed.
This method also may have discovered the first evidence for the EEG patterns of a definitive preictal
In this point of view, brain resetting, in which dynamics of cortical areas that converged during the preictal and ictal state diverge in the postictal state, may be captured by nonlinear signal analysis and help with understanding of the mechanisms of ictogenesis.
We assumed 2 minute periods before seizure onsets as preictal states, the seizures themselves as ictal states and 2 minute periods after seizure ends as postictal states.
For example, if the majority of 1sec segments in a 2min peri-ictal epoch were classified by the algorithm as preictal, the whole 2min epoch is characterized as preictal.
This scheme (Table II, columns 7-9) correctly classified the peri-ictal states of all seizures, except one out of the six seizures of patient #1, one preictal state of patient #2, and one ictal and one postictal state of patient #3.
Review of the Holter monitor data revealed a preictal rhythm consisting of sinus tachycardia rapidly deteriorating to sinus bradycardia with a 19-second period of asystole during the event.
EMU nurses also help to prevent preictal (before the seizure), intraictal (during a seizure), and postictal (after a seizure) complications.