Transcranial magnetic stimulation (TMS) is an increasingly popular tool for stroke rehabilitation. Consequently, researchers have started to explore the use of TMS in pediatric stroke. However, the application of TMS in a developing brain with pathologies comes with a unique set of challenges. The effect of TMS-induced electric fields has not been explored in children with stroke lesions. Here, we used finite element method (FEM) modeling to study how the electric field strength is affected by the presence of a lesion. We created individual realistic head models from MRIs (n = 6) of children with unilateral cerebral palsy due to perinatal stroke. We conducted TMS electric field simulations for coil locations over lesioned and non-lesioned hemispheres. We found that the presence of a lesion can strongly affect the electric field distribution. On the group level, the mean electric field strength did not differ between lesioned and non-lesioned hemispheres but exhibited a greater variability in the lesioned hemisphere. Other factors such as coil-to-cortex distance have a strong influence on the TMS electric field even in the presence of lesions. Our study has important implications for the delivery of TMS in children with brain lesions with respect to TMS dosing and coil placement.

Evidence-based assessment pathways inform early detection of cerebral palsy and access to intervention. This study investigated the relationships between early evidence-based assessments, diagnosis timeline, and rehabilitation intervention access in a population of children with cerebral palsy who were seen between 2010 and 2022 at the University of Wisconsin Waisman Center Newborn Follow Up Clinic. Cerebral palsy–specific assessments were increasingly integrated after the publication of early detection guidelines by Novak et al. in 2017. Age at cerebral palsy first mention (high risk for cerebral palsy) decreased over time, although age at diagnosis remained similar. Infants who received multiple evidence-based assessments were diagnosed at a younger age. Ninety-nine percent of children were referred to rehabilitation therapies before diagnosis. Infant age at referral to outpatient therapies decreased over time. This study provides novel clinical data on diagnosis timelines and identifies remaining gaps related to implementation feasibility toward improved early diagnosis and intervention access.

Single-pulse transcranial magnetic stimulation (TMS) has many applications for pediatric clinical populations, including infants with perinatal brain injury. As a noninvasive neuromodulation tool, single-pulse TMS has been used safely in infants and children to assess corticospinal integrity and circuitry patterns. TMS may have important applications in early detection of atypical motor development or cerebral palsy. The authors identified and summarized relevant studies incorporating TMS in infants, including findings related to corticospinal development and circuitry, motor cortex localization and mapping, and safety. This special report also describes methodologies and safety considerations related to TMS assessment in infants, and discusses potential applications related to diagnosis of cerebral palsy and early intervention. Single-pulse TMS has demonstrated safety and feasibility in infants with perinatal brain injury and may provide insight into neuromotor development and potential cerebral palsy diagnosis. Additional research in larger sample sizes will more fully evaluate the utility of TMS biomarkers in early diagnosis and intervention. Methodological challenges to performing TMS in infants and technical/equipment limitations require additional consideration and innovation toward clinical implementation. Future research may explore use of noninvasive neuromodulation techniques as an intervention in younger children with perinatal brain injury to improve motor outcomes.

Background/Objectives: Cerebral palsy (CP), often caused by early brain injury such as perinatal stroke or hemorrhage, is the most common lifelong motor disability. Early identification of at-risk infants and timely access to rehabilitation interventions are essential for improving long-term outcomes. The General Movements Assessment (GMA), performed in the first months of life, has high sensitivity and specificity to predict CP; however, the neurological correlates of general movements remain unclear. This analysis aimed to investigate the relationship between white matter integrity and general movements in infants with perinatal brain injury using advanced neuroimaging techniques. Methods: Diffusion-weighted MRI data were analyzed in 17 infants, 12 with perinatal brain injury and 5 typically developing infants. Tractography was used to identify the corticospinal tract, a key motor pathway often affected by perinatal brain injury, and tract-based spatial statistics (TBSS) were used to examine broader white matter networks. Diffusion parameters from the diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI) models were compared between infants with and without typical general movements. Results: Corticospinal tract integrity did not differ between groups when averaged across hemispheres. However, infants with asymmetric general movements exhibited greater corticospinal tract asymmetries. A subset of infants with atypical general movement trajectories at <6 weeks and 3–5 months of age showed reduced corticospinal tract integrity compared to those with typical general movements. TBSS revealed significant differences in white matter integrity between infants with typical and atypical general movements in several white matter pathways, including the corpus callosum, the right posterior corona radiata, bilateral posterior thalamic radiations, the left fornix/stria terminalis, and bilateral tapetum. Conclusions: These findings support and expand upon previous research suggesting that white matter integrity across multiple brain regions plays a role in the formation of general movements. Corticospinal integrity alone was not strongly associated with general movements; interhemispheric and cortical-subcortical connectivity appear critical. These findings underscore the need for further research in larger, diverse populations to refine early biomarkers of neurodevelopmental impairment and guide targeted interventions.