Understanding Brain Activity and Neuromotor Function in Infants at Low and High Risk for Neuromotor Impairment

Abstract

Neuromotor impairments (NMIs) encompass a range of conditions that disrupt movement, posture, and tone due to abnormalities in the developing brain. Brain activity that supports early motor development has yet to be elucidated in infants with NMIs, representing a major knowledge gap. This is a two-group cohort design including infants at high risk for neuromotor impairment (n=12) and those with no known risk factors (n=14). Infants were considered high-risk if they had at least one of the following risk factors: low birth weight, premature birth, multiple gestations, maternal infections or complications, and/or postnatal injury. First, we used optically pumped magnetometer magnetoencephalography (OPM-MEG) to examine differences in beta power over the sensorimotor cortex during an awake, naturalistic movement paradigm, which is also a validated assessment of movement quality. Neither beta power nor modulation differed across groups and movement/rest sessions. These findings suggest that beta oscillatory activity is more reflective of ongoing maturation and variability in sensorimotor organization; therefore, its sensitivity to detect differences in early infancy may be limited. Second, we used resting-state functional MRI to assess the relationship between motor network connectivity involving sensorimotor cortex (SMN), basal ganglia (BG), and thalamus with neuromotor function, as measured by the Hammersmith Infant Neurological Examination (HINE). There were no group differences in HINE scores, total and regional brain volumes, or in functional connectivity (FC) analyses of the sensorimotor or basal-ganglia-thalamocortical networks; however, a trend-level association was identified between the SMN and the thalamus. These findings suggest that FC in thalamocortical networks may serve as a more sensitive marker of early motor function during periods likely characterized by rapid developmental changes. Combined, the findings support the emergence of brain-behavior relationships as it relates to motor development.