The Role of the Corpus Callosum in Pediatric Dysphagia: Preliminary Findings from a Diffusion Tensor Imaging Study in Children with Unilateral Spastic Cerebral Palsy

The purpose of this study is to determine the relationship between the structural integrity of the corpus callosum (CC) and clinical feeding/swallowing performance in children with unilateral spastic cerebral palsy (USCP). Twenty children with USCP, (11 males, 5.11-17.6 yoa) were assessed via the Dysphagia Disorder Survey (DDS) and diffusion tensor imaging. Children were grouped into left hemisphere lesion (LHL; n = 13) and right hemisphere lesion (RHL; n = 7) groups. DTI variables analyzed for three CC regions (anterior, middle, posterior) were: fractional anisotropy (FA), radial diffusivity (RD), mean diffusivity (MD), and fibers count. Children with RHL presented with higher clinical dysphagia severity (p = 0.03). Six of seven children with RHL had lesions affecting periventricular/subcortical areas, and 8/13 children with LHL had lesions affecting the sensorimotor cortex. In the LHL group, as FA and fiber count of the anterior CC decreased and RD increased (all indicating reduced CC structural integrity), signs of dysphagia increased (r = -0.667, p = 0.013; r = -0.829, p <= 0.001; r = 0.594, p = 0.032, respectively). Reduced fiber count in the middle and posterior CC was also significantly associated with increased DDS scores (r = -0.762, p = 0.002; r = -0.739, p = 0.004, respectively). For the RHL group no significant correlations were observed. We provide preliminary evidence that corpus callosum integrity correlates with feeding/swallowing performance in children with USCP, especially when cortical sensorimotor areas of the left hemisphere are impacted. In this sample, CC integrity appeared to enable interhemispheric cortical plasticity for swallowing, but was not as critical when intrahemispheric connections were disrupted, as seen in the RHL group.