A comparison of structural morphometry in children and adults with persistent developmental stuttering

Hilary E Miller; Emily O Garnett; Elizabeth S Heller Murray; Alfonso Nieto-Castañón; Jason A Tourville; Soo-Eun Chang; Frank H Guenther

doi:10.1093/braincomms/fcad301

A comparison of structural morphometry in children and adults with persistent developmental stuttering

Brain Commun. 2023 Nov 6;5(6):fcad301. doi: 10.1093/braincomms/fcad301. eCollection 2023.

Authors

Hilary E Miller¹, Emily O Garnett², Elizabeth S Heller Murray^{1

3}, Alfonso Nieto-Castañón¹, Jason A Tourville¹, Soo-Eun Chang^{2

4

5}, Frank H Guenther^{1

6

7}

Affiliations

¹ Department of Speech, Language, & Hearing Sciences, Boston University, Boston, MA 02215, USA.
² Department of Psychiatry, University of Michigan, Ann Arbor, MI 48109, USA.
³ Department of Communication Sciences & Disorders, Temple University, Philadelphia, PA 19122, USA.
⁴ Department of Communication Disorders, Ewha Womans University, Seoul 03760, Korea.
⁵ Department of Communicative Sciences and Disorders, Michigan State University, East Lansing, MI 48824, USA.
⁶ Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA.
⁷ The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.

Abstract

This cross-sectional study aimed to differentiate earlier occurring neuroanatomical differences that may reflect core deficits in stuttering versus changes associated with a longer duration of stuttering by analysing structural morphometry in a large sample of children and adults who stutter and age-matched controls. Whole-brain T₁-weighted structural scans were obtained from 166 individuals who stutter (74 children, 92 adults; ages 3-58) and 191 controls (92 children, 99 adults; ages 3-53) from eight prior studies in our laboratories. Mean size and gyrification measures were extracted using FreeSurfer software for each cortical region of interest. FreeSurfer software was also used to generate subcortical volumes for regions in the automatic subcortical segmentation. For cortical analyses, separate ANOVA analyses of size (surface area, cortical thickness) and gyrification (local gyrification index) measures were conducted to test for a main effect of diagnosis (stuttering, control) and the interaction of diagnosis-group with age-group (children, adults) across cortical regions. Cortical analyses were first conducted across a set of regions that comprise the speech network and then in a second whole-brain analysis. Next, separate ANOVA analyses of volume were conducted across subcortical regions in each hemisphere. False discovery rate corrections were applied for all analyses. Additionally, we tested for correlations between structural morphometry and stuttering severity. Analyses revealed thinner cortex in children who stutter compared with controls in several key speech-planning regions, with significant correlations between cortical thickness and stuttering severity. These differences in cortical size were not present in adults who stutter, who instead showed reduced gyrification in the right inferior frontal gyrus. Findings suggest that early cortical anomalies in key speech planning regions may be associated with stuttering onset. Persistent stuttering into adulthood may result from network-level dysfunction instead of focal differences in cortical morphometry. Adults who stutter may also have a more heterogeneous neural presentation than children who stutter due to their unique lived experiences.

Keywords: FreeSurfer; MRI; cortical thickness; local gyrification index (LGI); persistent developmental stuttering.

Abstract

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