UC Irvine

High frequency oscillations (HFOs) are promising biomarkers of epileptic tissue. However, the impact of the measuring electrode size on HFO detection remains unknown. We, therefore, proposed a novel experimental technique for detecting high frequency oscillations in human intracranial data, in which we dynamically changed the electrode sizes by electrically shorting them. This enabled us to record oscillatory activity from a single brain location using electrode sizes that range from 1.08 mm2 to several square centimeters. This experiment was conducted in an in vitro modeling as well as an in vivo experiment using ECoG grids. Shorting of the channels on the ECoG grid mimicked different surface areas for the contact electrodes. Our experimental study confirmed that the rate of the HFOs detected is impacted by the electrode size, with smaller electrodes detecting more events. The results of this experiment can help to have a better understanding of the underlying neural generators, also can be used to have more optimal recording parameters. The result can also be directly used in clinical practices for seizure onset zone localization and surgical planning.