The use of amplitude-integrated electroencephalography (aEEG) to assess the severity of infant hypoxic-ischemic encephalopathy is beneficial (HIE). Based on 85 aEEG recordings recorded before six hours, Researchers determined the prevalence and investigated the source of misleading normal aEEG recordings. In patients with conflicting aEEG recordings and clinical symptoms, raw EEG recordings were reevaluated retrospectively with Fourier analysis to identify and describe the frequency patterns of the raw EEG signal. The raw EEG was used to calculate power spectral density curves, power (P), and medium frequency (MF). They discovered Non-depolarizing muscle relaxant (NDMR) exposure in seven cases. Before and after NDMR injection, EEG portions were studied and compared.

In four neonates, the aEEG was truly normal at the reevaluation. High voltage electrocardiographic (ECG) abnormalities were discovered in three infants with a flat trace on raw EEG. Ten newborns found the high-frequency component (HFC)  the cause of normal-appearing aEEG. In each case, HFC disappeared, but P and MF reduced dramatically after NDMR therapy. In newborns with HIE and hypothermia, the prevalence of false normal aEEG background pattern is relatively high. In hypothermic newborns, high-frequency EEG artifacts suggestive of shivering were the most common source of false normal aEEG. At the same time, they found high voltage ECG abnormalities were less common.