Exploring Functional Neuroplasticity and the Associations with Outcomes of Advanced Gross Motor Interventions for Children with Cerebral Palsy

Improvement of advanced gross motor skills is a key rehabilitation goal of children with cerebral palsy (CP), given their underlying brain injury, motor impairments, and physical activity participation possibilities. Evidence for potential functional neuroplastic change following gross motor training is lacking, and may provide important indicators that could advance intervention design to target children’s goals. This research focused on independently ambulatory children with hemiplegic CP (HCP) (i.e., those with unilateral motor involvement), and with diplegic CP (DCP) (i.e., those with both legs involved). In the first study, an ankle dorsiflexion functional magnetic resonance imaging (fMRI) paradigm was refined and optimized to calculate the ratio of hemispheric activity in the primary motor cortex (M1) and overall M1 activation volume. This fMRI paradigm was then used in two linked studies that explored relationships between changes in M1 activation and changes in advanced motor skills following goal-directed gross motor interventions for children with HCP and DCP. Lower limb M1 functional connectivity was also probed using resting state fMRI. Individual changes in fMRI outcomes were observed, with no significant group change. Three patterns of change in the laterality of M1 activation were identified: maintenance of principally contralateral activation (i.e. typical motor control), increased contralateral activation, or increased ipsilateral activation. Relationships were observed between motor skill gains and M1 activation during ankle dorsiflexion on the more affected/non-dominant side. For children with DCP, increased ipsilateral activity was associated with motor skill improvements. In both HCP and DCP, a smaller cortical activation volume was a predictor of motor skill gains. These exploratory findings suggest that M1 activation may be related to motor skill change. This investigation of lower limb functional neuroplasticity is an important step towards developing evidence of the underlying neural mechanisms of advanced gross motor skill improvement following interventions for children with CP.Ph.D