Quantification electroencephalography response to procedural pain during heel puncture in preterm infants

Objective. Pain assessment in preterm infants is often based on subjective observations, which may lack objectivity and are labor-intensive. Non-invasive EEG can serve as an objective assessment tool. However, no specific EEG feature within a particular frequency band and brain region has been reported for pain detection in the objective pain assessment of preterm infants. This study quantified electroencephalography (EEG) responses to procedural pain during a puncture in preterm infants, specifically analyzing three EEG parameters.Approach. Fifty-seven EEG datasets from forty-two preterm infants were analyzed across eight EEG channels. The differences between the upper and lower margins (UM-LM) of amplitude-integrated EEG (aEEG), as well as the five frequency bands (low delta, high delta, theta, alpha, and beta) of frequency power and time-frequency power, were used to characterize the response of the brain to pain during specific periods: before, during, and after the puncture.Main results. The Fp1 and Fp2 exhibited the most significant differences in the UM-LM aEEG differences between before vs during (Fp1:p= 0.0060, Fp2:p= 0.0031), before vs after (p< 0.0001), and during vs after (Fp1:p= 0.0427, Fp2:p= 0.025) the puncture. The C3 and C4 responded significantly to pain during the puncture in the frequency and time-frequency power, notably the time-frequency power in the low delta, which showed the most significant differences between the periods before vs during (p< 0.0001), before vs after (p< 0.0001), and during vs after (p= 0.0002) the puncture.Significance. The central brain region responds significantly to procedural pain in preterm infants, which is prominently detected in the low delta of time-frequency power. These findings support the use of EEG application as an objective and non-invasive method to identify and detect pain in nonverbal populations, focusing on specific critical channels and frequency bands.