The cortical response to a noxious procedure changes over time in preterm infants

Area of Science:

• Neuroscience
• Developmental Biology
• Neonatology

Background:

• Preterm infants experience repeated painful procedures during hospitalization.
• Understanding the developing brain's response to pain is crucial for pain management.

Purpose of the Study:

• To investigate changes in cortical response to repeated noxious stimuli in preterm infants.
• To explore the influence of central nervous system maturation and cumulative pain exposure on these responses.

Main Methods:

• Utilized multichannel near-infrared spectroscopy (NIRS) to measure cortical oxy-haemoglobin (HbO2) changes.
• Assessed 16 preterm infants (29-36 weeks postmenstrual age) during weekly heel-prick procedures.
• Analyzed the relationship between postmenstrual age (PMA), number of heel pricks, and cortical activation magnitude.

Main Results:

• Observed bilateral nociceptive event-related activation in the posterior frontal cortex.
• Found a significant positive correlation between increasing postmenstrual age and increased posterior frontal cortical activation (P < 0.001).
• Demonstrated an inverse relationship between the number of noxious events and the degree of cortical activation (P < 0.002).

Conclusions:

• Preterm newborns exhibit significant posterior frontal cortex activation to noxious stimuli.
• Cortical activation increases with postmenstrual age, indicating developmental changes.
• Decreased activation with repeated painful stimuli suggests experience-dependent neuroplasticity, possibly due to maturation and adaptation.