EEG synchronization changes during low-frequency electric stimulation of the seizure onset zone

Purpose: To assess whether EEG sychronization changes during short-term low-frequency electrical stimulation of the seizure onset zone. Methods: In 10 patients (34±11y) with pharmaco-resistant epilepsy the seizure onset zone (9 temporal lobe, 1 frontal lobe) was electrically stimulated by intracranial electrodes at 1Hz for 5min. Bipolar stimuli were applied and 4 different pulse widths (0.05,0.1,0.5 an 1.0ms) were tested. Stimulation amplitudes were held fixed at 1mA for strip electrodes and at 2mA for depth electrodes. Changes of EEG synchronization were assessed by the eigenvalue dynamics of the cross-correlat…