Purpose: We review two recent neuroanatomical studies of children who stutter (CWS), one that examines white matter integrity and the other that focuses on cortical gray matter morphology. In both studies, we sought to examine differences between children whose stuttering persists (“persistent”), children who recovered from stuttering (“recovered”), and their nonstuttering peers (“controls”). Method: Both of the reviewed studies use data from a large pediatric sample spanning preschool- to school-age children (3-10 years old at initial testing). Study 1 focused on surface-based measures of cortical size (thickness) and shape (gyrification) using structural magnetic resonance imaging, whereas Study 2 utilized diffusion tensor imaging to examine white matter integrity. Results: In both studies, the main difference that emerged between CWS and fluent peers encompassed left hemisphere speech motor areas that are interconnected via the arcuate fasciculus. In the case of white matter integrity, the temporoparietal junction and posterior superior temporal gyrus, both connected via the left arcuate fasciculus, and regions along the corpus callosum that contain fibers connecting bilateral motor regions were significantly decreased in white matter integrity in CWS compared to controls. In the morphometric study, children who would go on to have persistent stuttering specifically had lower cortical thickness in ventral motor and premotor areas of the left hemisphere. Conclusion: These results point to aberrant development of cortical areas involved in integrating sensory feedback with speech movements in CWS and differences in interhemispheric connectivity between the two motor cortices. Furthermore, developmental trajectories in these areas seem to diverge between persistent and recovered cases.
|Number of pages||13|
|Journal||Journal of Speech, Language, and Hearing Research|
|State||Published - Aug 2019|
Bibliographical noteFunding Information:
This study was supported by Awards R01DC011277 (S. C.) and R21DC015312 (S. C.) from the National Institute on Deafness and Other Communication Disorders and the Matthew K. Smith Stuttering Research Fund. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute on Deafness and Other Communication Disorders or the National Institutes of Health. The authors thank all the children and parents who have participated in this study. The authors also thank David Zhu for his support on magnetic resonance imaging (MRI) scanning protocols; Kristin Hicks; Saralyn Rubsam; Megan Sheppard for her assistance in participant recruitment, behavioral testing, and help with MRI data collection; Scarlett Doyle for her assistance in MRI data acquisition; Barbara Holland for assistance with data quality control; and Ashley Diener for her assistance in speech data analyses.
© 2019 American Speech-Language-Hearing Association.