title: Diffusion imaging of cerebral white matter in persons who stutter: evidence for network-level anomalies.
abstract: Deficits in brain white matter have been a main focus of recent neuroimaging studies on stuttering. However, no prior study has examined brain connectivity on the global level of the cerebral cortex in persons who stutter (PWS). In the current study, we analyzed the results from probabilistic tractography between regions comprising the cortical speech network. An anatomical parcellation scheme was used to define 28 speech production-related ROIs in each hemisphere. We used network-based statistic (NBS) and graph theory to analyze the connectivity patterns obtained from tractography. At the network-level, the probabilistic corticocortical connectivity from the PWS group were significantly weaker than that from persons with fluent speech (PFS). NBS analysis revealed significant components in the bilateral speech networks with negative correlations with stuttering severity. To facilitate comparison with previous studies, we also performed tract-based spatial statistics (TBSS) and regional fractional anisotropy (FA) averaging. Results from tractography, TBSS and regional FA averaging jointly highlight the importance of several regions in the left peri-Rolandic sensorimotor and premotor areas, most notably the left ventral premotor cortex (vPMC) and middle primary motor cortex, in the neuroanatomical basis of stuttering.
authors.affiliation: Department of Speech, Language and Hearing Sciences, Sargent College of Health and Rehabilitation Sciences, Boston University Boston, MA, USA.
authors.forename: Shanqing
authors.initials: S
authors.lastname: Cai
authors.affiliation: Department of Speech, Language and Hearing Sciences, Sargent College of Health and Rehabilitation Sciences, Boston University Boston, MA, USA.
authors.forename: Jason A
authors.initials: JA
authors.lastname: Tourville
authors.affiliation: Department of Communication Sciences and Disorders and the Institute for Stuttering Treatment and Research, Faculty of Rehabilitation Medicine, University of Alberta Edmonton, AB, Canada.
authors.forename: Deryk S
authors.initials: DS
authors.lastname: Beal
authors.affiliation: Department of Speech, Language and Hearing Sciences, Sargent College of Health and Rehabilitation Sciences, Boston University Boston, MA, USA.
authors.forename: Joseph S
authors.initials: JS
authors.lastname: Perkell
authors.affiliation: Department of Speech, Language and Hearing Sciences, Sargent College of Health and Rehabilitation Sciences, Boston University Boston, MA, USA.
authors.forename: Frank H
authors.initials: FH
authors.lastname: Guenther
authors.affiliation: Department of Brain and Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology Cambridge, MA, USA.
authors.forename: Satrajit S
authors.initials: SS
authors.lastname: Ghosh
keywords: brain connectivity; diffusion tensor imaging; probabilistic tractography; regions of interest (ROIs); speech disorders; stuttering; white matter