Hypokinetic dysarthria (HD) is a difficult-to-treat symptom affecting quality of life in patients with Parkinson’s disease (PD). Levodopa may partially alleviate some symptoms of HD in PD, but the neural correlates of these effects are not fully understood. The aim of our study was to identify neural mechanisms by which levodopa affects articulation and prosody in patients with PD. Altogether 20 PD patients participated in a task fMRI study (overt sentence reading). Using a single dose of levodopa after an overnight withdrawal of dopaminergic medication, levodopa-induced BOLD signal changes within the articulatory pathway (in regions of interest; ROIs) were studied. We also correlated levodopa-induced BOLD signal changes with the changes in acoustic parameters of speech. We observed no significant changes in acoustic parameters due to acute levodopa administration. After levodopa administration as compared to the OFF dopaminergic condition, patients showed task-induced BOLD signal decreases in the left ventral thalamus (p = 0.0033). The changes in thalamic activation were associated with changes in pitch variation (R = 0.67, p = 0.006), while the changes in caudate nucleus activation were related to changes in the second formant variability which evaluates precise articulation (R = 0.70, p = 0.003). The results are in line with the notion that levodopa does not have a major impact on HD in PD, but it may induce neural changes within the basal ganglia circuitries that are related to changes in speech prosody and articulation.

运动机能障碍（HD）是一种难以治疗的症状，影响帕金森病（PD）患者的生活质量。左旋多巴可能部分缓解 PD 中 HD 的某些症状，但这些作用的神经相关性尚未完全了解。我们研究的目的是确定左旋多巴影响 PD 患者发音和韵律的神经机制。共有 20 名 PD 患者参加了任务功能磁共振成像研究（公开句子阅读）。在过夜停用多巴胺能药物后使用单剂量左旋多巴，研究了左旋多巴诱导的关节通路内的 BOLD 信号变化（在感兴趣的区域；ROI）。我们还将左旋多巴引起的 BOLD 信号变化与语音声学参数的变化相关联。我们观察到急性左旋多巴给药导致声学参数没有显着变化。与关闭多巴胺能状态相比，给予左旋多巴后，患者在左腹侧丘脑中表现出任务诱导的 BOLD 信号减少（p  = 0.0033）。丘脑激活的变化与音调变化的变化相关（R  = 0.67，p  = 0.006），而尾状核激活的变化与评估精确发音的第二共振峰变化的变化相关（R  = 0.70，p  = 0.003） ）。结果与左旋多巴对 PD 中的 HD 没有重大影响的观点一致，但它可能会引起基底神经节回路内的神经变化，这些变化与言语韵律和发音的变化有关。