Lighting Up Babies' Brains

Detecting Gamma Band EEG Waves in Infants

Lead: Liisa Holsti
Collaborators: Dr. Guy Dumont

Baby in an incubator

In Canada, more than 30,000 infants are born preterm annually. In the NICU, these infants are exposed routinely to 5-15 painful procedures/day (e.g., blood draws), with cumulative exposure as high as 300-400 procedures over an admission. Each painful procedure causes immediate hemodynamic instability, destabilization of behaviour, and cerebral blood flow. This early pain exposure is associated with damaged brain microstructure and processing, as well as adverse motor and cognitive outcomes.

Brain protection is a key goal of effective pain management in premature infants. Measuring the effects of procedural pain and stress on the brain in real-time is crucial. Near-infrared spectroscopy (NIRS) can help evaluate acute changes in cerebral blood flow, volume and oxygenation; however, interpretation of results can be complex because neurovascular coupling is subject to maturation-related variability. Recent work suggests that co-registration of electroencephalography (EEG) may greatly reduce the misinterpretation of NIRS in premature infants.

Thus, our aims are to develop and to pilot test an integrated NIRS/EEG system for preterm infants.

This work is done in collaboration with Dr. Guy Dumont and NR Sign. Our team received a seed grant from BCCHRI to develop a new “premie”- sized integrated NIRS/EEG machine which is now in its final stages of gaining Health Canada approval. We will begin the first pilot feasibility study using Neolite for recording brain activity.

We will develop a prototype and conduct a clinical feasibility study with 10 medically stable preterm infants born between 27-37 weeks gestational age from the NICU at BC Women’s Hospital. Infants will be monitored continuously using video and the NIRS/EEG system during a single blood draw, needed for clinical management. Outcome measures will include: changes in cerebral oxygenation (NIRS oxy-, deoxy-, and total hemoglobin); low frequency EEG (delta waves); ultra-low frequency EEG; high frequency EEG (gamma waves); NIRS-EEG spectral coherence (a measure of neurovascular coupling); and total scores on the Behavioral Indicators of Infant Pain (BIIP). Exploratory analyses will include  examining correlations between NIRS/EEG and BIIP total scores.

This work will advance our understanding of the effects of pain and stress on preterm infants, and will facilitate evaluation of the most advanced brain-protective treatments. What is so important about this device is that in adults it can detect gamma band EEG waves. There are no single biomarkers of pain in adults or in infants, but gamma band waves have been very strongly associated with a pain signal in adults. These waves have never been recorded in preterm infants and we hope to be the first to do so.