Assessment of the contralesional corticospinal tract in early-onset pediatric hemiplegia: Preliminary findings.

While pediatric hemiplegia results from a unilateral lesion, the immature state of the brain at the time of injury increases the likelihood of observing changes in the non-lesioned hemisphere as well. The purpose of this preliminary study was to use diffusion tensor imaging to evaluate the contralesional corticospinal tracts in individuals with early-onset pediatric hemiplegia. Twelve individuals with pediatric hemiplegia and ten age-matched controls underwent diffusion tensor imaging (DTI). Corticospinal projections were reconstructed using probabilistic tractography for both the lesioned and contralesional side in pediatric hemiplegia as well as the dominant and non-dominant sides in control subjects. The contralesional tract was found to have decreased white matter integrity relative to control subjects. Compared to controls, the contralesional tract also showed increased tract volume. The increase in volume suggests the presence of ipsilateral corticospinal projections from the contralesional hemisphere that are maintained during development to control the paretic extremities. Decreases in integrity may be explained by diffuse damage or incomplete maturation. The findings of this study support the notion of bilateral motor involvement in pediatric hemiplegia, and the need to address bilateral neural changes as well as motor deficits in this population.