Reduced perfusion in Broca's area in developmental stuttering

Area of Science:

• Neuroimaging
• Neuroscience
• Speech and Language Sciences

Background:

• Developmental stuttering is a complex speech disorder affecting millions worldwide.
• The underlying neurobiological mechanisms of stuttering remain incompletely understood.
• Cerebral blood flow (CBF) is a key indicator of brain activity and metabolic function.

Purpose of the Study:

• To investigate resting cerebral blood flow (rCBF) differences in children and adults with developmental stuttering compared to fluent controls.
• To explore the relationship between rCBF, stuttering severity, and motor speed.

Main Methods:

• Pulsed arterial spin labeling (ASL) MRI was used to acquire perfusion data.
• 26 individuals who stutter and 36 fluent controls participated.
• Voxel-wise comparisons were performed, controlling for age, sex, and IQ.

Main Results:

• Reduced rCBF was observed in Broca's area and the superior frontal gyrus in the stuttering group.
• Lower rCBF in Broca's area correlated with increased stuttering severity.
• Increased rCBF was found in cerebellar nuclei and parietal cortex in individuals who stutter.

Conclusions:

• Reduced rCBF in Broca's region is a characteristic of developmental stuttering.
• Stuttering severity is associated with the degree of rCBF reduction in language-related brain areas.
• Aberrant rCBF within the language loop may contribute to the pathophysiology of stuttering severity.