Comparison of Amplitude-Integrated EEG and Conventional EEG in a Cohort of Premature Infants

Objective: To compare amplitude-integrated EEG (aEEG) and conventional EEG (EEG) activity in premature neonates. Methods: Biweekly aEEG and EEG were simultaneously recorded in a cohort of infants born less than 34 weeks gestation. aEEG recordings were visually assessed for lower and upper border amplitude and bandwidth. EEG recordings were compressed for visual evaluation of continuity and assessed using a signal processing software for interburst intervals (IBI) and frequencies' amplitude. Ten-minute segments of aEEG and EEG indices were compared using regression analysis. Results: A total of 189 recordings from 67 infants were made, from which 1697 aEEG/EEG pairs of 10-minute segments were assessed. Good concordance was found for visual assessment of continuity between the 2 methods. EEG IBI, alpha and theta frequencies' amplitudes were negatively correlated to the aEEG lower border while conceptional age (CA) was positively correlated to aEEG lower border (P <.001). IBI and all frequencies' amplitude were positively correlated to the upper aEEG border (P ≤.001). CA was negatively correlated to aEEG span while IBI, alpha, beta, and theta frequencies' amplitude were positively correlated to the aEEG span. Conclusions: Important information is retained and integrated in the transformation of premature neonatal EEG to aEEG. Significance: aEEG recordings in high-risk premature neonates reflect reliably EEG background information related to continuity and amplitude.