Dependency ECoG Band Spectrum in Epileptic Discharges Upon Local Cooling Rate on Brain

Focal brain cooling has recently drawn attention as a less-invasive treatment for intractable epileptic patients. The objective of this study is to investigate the dependence of brain cooling rate on epileptic discharges (EDs) suppression with experiments using four epilepsy model rat. EDs were induced by Penicillin G in anesthetized rat, and cooled to 16 °C under four different time conditions (30, 60, 100 and 200 second, respectively). The ECoG obtained from the experiments were sorted into frequency band components which have physiological significance. The results of frequency analyses confirmed that the suppression of EDs have a cooling rate dependency, and power of four frequency bands (delta, theta, alpha and beta waves) in EDs are smaller when the cooling rate is slower. Our results suggested that slower cooling on brain surface can effectively suppress EDs and rapid brain cooling is not necessarily the best way. This finding implied that there are optimum cooling condition depending on the degree of EDs or epileptic symptoms.