Subband EEG complexity after global hypoxic-ischemic brain injury

Hypoxic-ischemic (HI) brain injury after cardiac arrest (CA) causes the main morbidity and mortality of the patients. The mechanism of HI neurological injury and its real time detection and monitoring have been extensively studied in the past years. The electroencephalogram (EEG) following CA has been investigated to provide a noninvasive monitoring strategy. In this present work, we studied the complexity of the EEG signal after HI injury. Sample entropy (SampEn) is applied to analyze the EEG in different frequency bands (delta, theta, alpha and beta). The "alpha vulnerability" in rhythmic complexity is observed, which indicated that among different EEG rhythmic subbands, alpha wave shows a distinct SampEn decrease during the early recovery period after HI injury. The alpha vulnerability is confirmed by our previous research on the vulnerability in thalamic somatosensory pathway. The results may help us develop means to restore electrical function recovery after HI.