Somatic stimulation causes frontoparietal cortical changes in neonates: a functional near-infrared spectroscopy study

Area of Science:

• Neuroscience
• Neonatal Physiology
• Biomedical Engineering

Background:

• Palmar and plantar grasp reflexes are crucial primitive neonatal functions.
• Persistence of these reflexes can indicate developing cerebral palsy.
• Assessing neonatal brain activity non-invasively is vital for early detection.

Purpose of the Study:

• To evaluate the feasibility of using functional near-infrared spectroscopy (fNIRS) in a clinical setting for neonatal brain activity measurement.
• To characterize changes in oxyhemoglobin (HbO) and deoxyhemoglobin (HbD) concentrations in the frontoparietal cortex of neonates.
• To investigate brain responses to different somatic stimuli (palmar, plantar, oromotor) in unsedated neonates.

Main Methods:

• Functional near-infrared spectroscopy (fNIRS) was used to measure HbO and HbD concentrations in the bilateral frontoparietal cortex of preterm neonates.
• Thirteen preterm neonates participated, with some returning for a second measurement.
• Responses to palmar, plantar, and oromotor stimuli were recorded and analyzed using linear mixed models.

Main Results:

• Oromotor stimulation elicited a significantly longer duration response (50% greater) in both left and right hemisphere HbO compared to palmar or plantar stimuli.
• No other statistically significant differences were found between stimuli for other measured outcomes (amplitude, latency).
• The study demonstrated the efficacy of fNIRS for studying neurophysiological mechanisms in neonates.

Conclusions:

• Functional near-infrared spectroscopy (fNIRS) is a feasible and effective tool for studying neonatal brain responses to somatic stimulation at the crib-side.
• Differential brain responses to oromotor stimulation suggest potential for targeted neurodevelopmental assessments.
• fNIRS can be integrated with occupational and physical therapy to investigate restorative neurophysiological mechanisms in neonates.