Localizing epileptic focus and assessing electrical stimulus effects on epilepsy in rats using stretchable micro electrocorticogram electrodes

Abstract

Epilepsy is a chronic nervous disease with increasing incidence worldwide, while the accurate localization of epileptic focus and the corresponding treatment are still challenging due to the lack of effective tools to monitor and modulate the related brain neurological activities. In this work, stretchable micro electrocorticogram (mECoG) electrodes are developed and used to investigate penicillin-induced epilepsy in rats. The electrodes possess excellent stretchability, conformality, anti-interference ability and sufficient resolution to successfully monitor electroencephalogram (EEG) signals, which is superior to traditional rigid polyimide-based electrodes. Characteristic epileptic spike waves are detected and analyzed to study the epileptic focus and electrical stimulus effects during epileptic seizures. It is found that the spike waves occur first in the visual cortex which is likely to be the epileptic focus. Epileptic spike wave frequency quickly increases to 1.07 Hz where it reaches a plateau and remains stable. There is no dominant brain hemisphere that would show early warning of epileptic seizures. Electrical stimuli for various times are applied after administering penicillin. It is found that 15 min of electrical stimulus has the best restraining effect on epileptic seizures. The mECoG electrodes developed in this study show potentials for applications in stretchable biomedical devices.