Neuroanatomical differences in adults and children who stutter: a voxel-based morphometry study

Background: Previous functional and anatomical neuroimaging studies have reported physiological and structural differences in adults who stutter and children who stutter compared to fluent controls. However, a comparison of neuroanatomical differences between adult group and children group has not been reported in the literature. The current study examined neuroanatomical differences in groups of adults and groups of children separately. This study reported on the neuroanatomical changes in brains of people who stutter from childhood to adulthood by descriptively comparing the results of the adult data and child data. Using the same dataset, the present study also attempted to replicate the comparisons in Chang et al. (2008) study. Methods: High resolution MRI data from adult and children groups were analyzed separately with voxel-based morphometry (VBM), an unbiased, whole-brain based volumetric technique. Adult group comparisons consisted of adults who stutter (n=12) versus adult controls (n=25), and pediatric group comparisons included recovered children (n=7); children with persistent stuttering (n=8), and normally fluent children (n=7). Results: Our findings demonstrated significant gray and white matter volume differences in brain areas important for speech production in adults who stutter, children with persistent stuttering, and recovered children relative to controls. These areas included subcortical structures, cortical areas, as well as cerebellar regions. Conclusions: Developmental stuttering could be related to aberrant gray and white matter volumes in a widely distributed neural network which may lead to disrupted transmission of sensory or motor information among speech relevant areas in this neural circuitry. In addition, aberrant development pattern in these areas may present risk for the onset of stuttering