Cerebellar-cortical loops comprise critical neural circuitry that supports self-initiated movements and motor adjustments in response to perceived errors, functions that are affected in stuttering. It is unknown whether structural aspects of cerebellar circuitry are affected in stuttering, particularly in children close to symptom onset. Here we examined white matter diffusivity characteristics of the three cerebellar peduncles (CPs) based on diffusion MRI (dMRI) data collected from 41 children who stutter (CWS) and 42 controls in the 3–11 years range. We hypothesized that CWS would exhibit decreased fractional anisotropy (FA) in the right CPs given the contralateral connectivity of the cerebellar-cortical loops and past reports of structural differences in left cortical areas in stuttering speakers. Automatic Fiber Quantification (AFQ) was used to track and segment cerebellar white matter pathways and to extract diffusivity measures. We found significant group differences for FA in the right inferior CP (ICP) only: controls showed significantly higher FA in the right ventral ICP compared to CWS, controlling for age, sex, and verbal IQ. Furthermore, FA of right ICP was negatively correlated with stuttering frequency in CWS. These results suggest an early developmental difference in the right ICP for CWS compared to age-matched peers, which may indicate an alteration in error processing, a function previously linked to the ICP. Lower FA here may impact error monitoring and sensory input processing to guide motor corrections. Further longitudinal investigations in children may provide additional insights into how CP development links to stuttering persistence and recovery.

小脑皮质环路包含关键的神经回路，支持自主运动和运动调整，以响应感知错误，以及口吃中受影响的功能。目前尚不清楚小脑回路的结构是否会受到口吃的影响，尤其是在接近症状出现的儿童中。在这里，我们根据从 41 名口吃儿童 (CWS) 和 42 名 3-11 岁对照儿童收集的扩散 MRI (dMRI) 数据，检查了三个小脑脚 (CP) 的白质扩散特征。考虑到小脑皮质环路的对侧连通性以及过去关于口吃说话者左皮质区域结构差异的报道，我们假设 CWS 会在右侧 CP 中表现出分数各向异性 (FA) 降低。自动纤维定量（AFQ）用于跟踪和分割小脑白质通路并提取扩散率测量值。我们仅发现右下 CP (ICP) 的 FA 存在显着的组间差异：在控制了年龄、性别和言语智商的情况下，与 CWS 相比，对照组的右腹 ICP 中的 FA 显着更高。此外，右ICP的FA与CWS的口吃频率呈负相关。这些结果表明，与年龄匹配的同龄人相比，CWS 的正确 ICP 存在早期发育差异，这可能表明错误处理（之前与 ICP 相关的功能）发生了变化。此处较低的 FA 可能会影响误差监控和感官输入处理，以指导电机校正。对儿童的进一步纵向研究可能会为 CP 发展与口吃持续性和恢复之间的关系提供更多见解。