The contribution of mirror neuron system activation to goal-directed action observation therapy in pediatric unilateral cerebral palsy Doi: https://doi.org/10.55522/jhpo.V2I5.0044

Abstract

Action Observation Therapy (AOT) shows promise in pediatric neurorehabilitation for improving upper limb function. Its proposed mechanism, mirror neuron system (MNS) activation, is largely inferred from adult studies, creating a significant evidence gap in children with unilateral cerebral palsy (UCP). This study aimed to directly measure MNS activation via functional MRI (fMRI) in children with UCP during a goal-directed AOT paradigm and correlate it with functional motor improvements. In a randomized controlled trial, 30 children with UCP (ages 6-12, MACS I-III) were allocated to either AOT (n=15) or control (n=15) groups. The AOT group observed goal-directed actions followed by physical practice, while the control group observed geometric shapes followed by the same practice. Pre- and post-intervention assessments included fMRI scans during action observation and the Assisting Hand Assessment (AHA) and Melbourne Assessment 2 (MA2) for functional evaluation. The AOT group demonstrated significantly greater activation in key MNS regions (inferior frontal gyrus, premotor cortex, inferior parietal lobule) on fMRI (p < 0.001, FWE-corrected). This was coupled with significantly greater improvement on the AHA (mean difference +5.6 points, p=0.002) and MA2 (mean difference +7.1%, p=0.005) compared to the control group. A strong positive correlation was found between the change in MNS activation and the change in AHA scores (r = 0.78, p < 0.001). This study provides the first direct evidence in a pediatric population that functional gains from goal-directed AOT are mediated by the activation of the MNS. It validates AOT as a neuroplasticity-based intervention and underscores the importance of goal-directed action observation in designing effective rehabilitation protocols for children with UCP.