Neural network connectivity differences in children who stutter

TLDR

Stuttering, affecting about 1 % of children, disrupts the precise millisecond‑scale coordination of speech‑related motor systems, leads to psychosocial difficulties, and its neural origins remain poorly understood. The study investigates neural network differences in children who stutter by combining resting‑state fMRI and probabilistic tractography. Researchers compared synchronized activity between speech‑production regions and the white‑matter tracts connecting them in 3–9‑year‑old children who stutter versus age‑matched controls. Children who stutter show reduced connectivity in timing‑control networks, with altered auditory‑motor and basal ganglia‑thalamocortical pathways that likely impair speech planning and execution.

Abstract

Affecting 1% of the general population, stuttering impairs the normally effortless process of speech production, which requires precise coordination of sequential movement occurring among the articulatory, respiratory, and resonance systems, all within millisecond time scales. Those afflicted experience frequent disfluencies during ongoing speech, often leading to negative psychosocial consequences. The aetiology of stuttering remains unclear; compared to other neurodevelopmental disorders, few studies to date have examined the neural bases of childhood stuttering. Here we report, for the first time, results from functional (resting state functional magnetic resonance imaging) and structural connectivity analyses (probabilistic tractography) of multimodal neuroimaging data examining neural networks in children who stutter. We examined how synchronized brain activity occurring among brain areas associated with speech production, and white matter tracts that interconnect them, differ in young children who stutter (aged 3–9 years) compared with age-matched peers. Results showed that children who stutter have attenuated connectivity in neural networks that support timing of self-paced movement control. The results suggest that auditory-motor and basal ganglia-thalamocortical networks develop differently in stuttering children, which may in turn affect speech planning and execution processes needed to achieve fluent speech motor control. These results provide important initial evidence of neurological differences in the early phases of symptom onset in children who stutter.