Structural brain alterations in persistent developmental stuttering: a whole-brain voxel-based morphometry (VBM)...

Persistent developmental stuttering (PDS), also known as childhood-onset speech fluency disorder, is characterized by involuntary disruptions in normal speech fluency, such as sound repetitions, prolongations, and silent pauses. Although structural neuroimaging techniques, particularly voxel-based morphometry (VBM), have been widely used to explore brain abnormalities in PDS, the precise brain regions predominantly affected remain unclear. This study aimed to investigate grey matter (GM) and white matter (WM) volumetric differences in adults with PDS compared to fluent speakers.

Magnetic resonance imaging (MRI) scans were obtained from 15 adults with PDS and 15 fluent control participants matched for age, sex, education, and hand preference. Whole-brain VBM analysis was conducted to assess GM and WM volume differences between the two groups.

Compared to fluent speakers, adults with PDS demonstrated reduced WM volume in the cerebellum. GM alterations included increased volumes in the right postcentral gyrus and the left middle temporal gyrus (MTG), while decreased volumes were observed in the left superior frontal gyrus (SFG), bilateral paracentral lobule, right cuneus, and right cerebellum.

These findings provide evidence of both grey and white matter abnormalities in adults with PDS, highlighting the involvement of specific cortical and subcortical regions. The results support the significance of structural brain differences in understanding the neurobiological basis of persistent stuttering.