Poster A11, Tuesday, August 20, 2019, 10:15 am – 12:00 pm, Restaurant Hall
Gray and white matter developmental trajectories associated with persistence and recovery of childhood stuttering
Simone Koenraads1, Gregory Spray2,3, Ho Ming Chow2,4, Emily Garnett2, Soo-Eun Chang2,3;1Erasmus University Medical Center, Rotterdam, 2University of Michigan, Ann Arbor, 3Michigan State University, East Lansing, 4Nemours/Alfred I. DuPont Hospital for Children
Developmental stuttering is a complex neurodevelopmental disorder affecting 5-8% of preschool-age children. Most children recover, while 1% go on to develop chronic life-long stuttering. The neural bases for persistence versus natural recovery from stuttering remain unclear. Previous neuroimaging studies in children who stutter (CWS) have shown structural anomalies in speech-motor brain areas relative to fluent peers. Past studies, however, involved relatively small sample sizes and cross-sectional designs that limited our ability to track developmental changes linked to persistence and recovery of stuttering. In this first longitudinal study examining gray (GMV) and white matter volume (WMV) developmental trajectories, we conducted voxel-based morphometry (VBM) to compare children with persistent stuttering (pCWS), recovered from stuttering (rCWS), and fluent controls. Based on previous findings reported by us and others, we hypothesized that pCWS and rCWS exhibit reduced GMV in the left inferior frontal gyrus (IFG) and ventral premotor cortex. We also hypothesized that rCWS would show increases in WMV with age in the superior temporal gyrus (STG) and greater GMV and WMV in structures supporting speech planning and timing (cerebellum, basal ganglia). Based on data reported on persistent stuttering, we expected pCWS would exhibit greater somatosensory area volume increases as well as right sided motor area volume increases. A total of 286 MRI scans from 43 CWS (26 pCWS and 17 rCWS) and 44 fluent peers between 3 and 12 years of age were entered for analysis. Each participant was scanned up to four times, with an average inter-scan interval of 1 year. We examined group differences (pCWS, rCWS, fluent control) and group by age interactions in GMV and WMV, incorporating sex, IQ, brain size, and socioeconomic status as covariates of no interest. In terms of gray matter, both pCWS and rCWS exhibited significantly reduced GMV relative to controls in the left IFG. pCWS showed greater GMV relative to controls in the left postcentral gyrus, right precentral gyrus and greater GMV relative to rCWS in the left cerebellum and left postcentral gyrus. rCWS showed greater GMV in the left cerebellum relative to controls and right thalamus relative to pCWS. There were significant age-related GMV increases in the bilateral putamen for rCWS relative to the other two groups (all contrasts thresholded at p< .05 corrected). In terms of white matter, rCWS showed significantly greater WMV in the bilateral STG relative to controls and greater right STG relative to pCWS. They also showed significant age-related increases in the left STG and bilateral cerebellum (IX) relative to controls. In sum, we found structural changes that suggest increased motor and somatosensory involvement in pCWS, and greater auditory, subcortical and cerebellar involvement in rCWS. Both pCWS and rCWS exhibited less GMV in the left IFG, replicating earlier reports that pointed to reduced GMV in left IFG in CWS as a group. Greater bilateral STG and subcortical involvement may reflect structural compensatory developmental changes conducive to recovery from stuttering. These findings provide novel insights into possible neural mechanisms of persistence and recovery of childhood stuttering.
Themes: Disorders: Developmental, Speech Motor Control
Method: Other