Haemodynamic Responses to Spontaneous Neural Activity on the Electroencephalogram in Preterm Infants

Area of Science:

• Neuroscience
• Developmental Neuroscience
• Neonatal Physiology

Background:

• Delta brushes are spontaneous neural activities in preterm electroencephalograms (EEGs), linked to subplate neuron function.
• Understanding the hemodynamic correlates of delta brushes is crucial for assessing early brain development.

Purpose of the Study:

• To investigate hemodynamic responses associated with delta brushes in preterm infants using simultaneous EEG-NIRS.
• To analyze the spatial distribution and temporal patterns of these hemodynamic responses in relation to infant age.

Main Methods:

• Simultaneous electroencephalography (EEG) and functional near-infrared spectroscopy (NIRS) were used in five preterm infants.
• An automated algorithm detected delta brushes; NIRS measured oxy- and deoxy-hemoglobin changes.
• Hemodynamic responses were classified into five patterns and analyzed based on location and infant postmenstrual age.

Main Results:

• Predominant positive hemodynamic responses (oxy-hemoglobin increases) were observed, extending beyond local areas.
• Notable responses were detected in bilateral temporal regions.
• The proportion of anti-phase positive responses increased significantly from 12% at 33-34 weeks to 54% at 36 weeks postmenstrual age.

Conclusions:

• Localized neuronal activity (delta brushes) elicits widespread hemodynamic responses in the developing brain.
• The increasing anti-phase responses with age suggest maturational changes in neural network communication.
• Findings support the hypothesis of the insula as a highly interconnected hub in the developing brain.