Nonextensive entropy measure of EEG following brain injury from cardiac arrest

The nonextensive entropy measure is developed to study the electroencephalogram (EEG) during the recovery of the brain's electrical function from asphyxic cardiac arrest (ACA) injury. The statistical characteristics of the Tsallis-like time-dependent entropy (TDE) for different signal distributions are investigated. Both the mean and the variance of TDE show good specificity to the ACA brain injury and its recovery. ACA brain injury results in a decrease in entropy while a good electrophysiological recovery shows a rapid return to a higher entropy level. There is a reduction in the mean and increase in the variance of TDE after brain injury followed by a gradual recovery upon resuscitation. The nonextensive TDE is expected to provide a novel quantitative EEG strategy for monitoring the brain states.