Scaling exponents of EEG are related to the temporal process of the therapeutic hypothermia following ischemic brain injury

Several markers based on quantitative electroencephalogram (qEEG) analysis have been associated with the neuroprotective effects of therapeutic hypothermia on hypoxic-ischemic encephalopathy (HIE) after cardiac arrest (CA). Nevertheless, the makers by far have not been linked to the temporal process of the ischemic neuronal death. In this study, we investigated the long-range correlations in EEG power in thetas and alpha bands before and after CA by detrended fluctuation analysis (DFA). The scaling components by DFA showed that the short-term scaling exponent in alpha band (i.e. gamma₁ ^alpha) was well correlated with recovery of brain injury during the latent phase. While the short-term scaling exponent in thetas band (i.e. gamma₁ ^thetas) and the long-term scaling exponent in alpha band (i.e. gamma₂ ^alpha) were correlated with the delayed neuronal death after CA. Our preliminary results showed that the long-range correlations in thetas and alpha bands could be related the detail temporal process of therapeutic hypothermia.