Developmental stuttering (DS) is a disturbance of the normal rhythm of speech that may result as very debilitating in the most affected cases. Interventions for DS are historically based on behavioral modifications of speech patterns (e.g. by means of speech therapy), useful to regain a better speech fluency. However, great variability in intervention outcomes is normally observed, and no definitive evidence is currently available to resolve stuttering, especially when it persists in adulthood. In the last decades, DS has been increasingly considered as a functional disturbance, affecting the correct programming of complex motor sequences, such as speech. Compatibly, understanding of the neurophysiological bases of DS has dramatically improved, thanks to neuroimaging, and techniques able to interact with neural tissue functioning (e.g. Non-Invasive Brain Stimulation -NIBS-). In this context, a dysfunctional activity of the cortico-basal-thalamo-cortical networks seems to play a key role, as well as defective patterns of connectivity, especially in sensorimotor networks. As a consequence, acting directly on the functionality of “defective” or “impaired” brain circuits may help people who stutter to better manage dysfluencies. This may also “potentiate” available interventions, thus favoring more stable outcomes of speech fluency. Attempts aiming at modulating (and improving) brain functioning of people who stutter, realized by using NIBS, are quickly increasing. Here, we will review these recent advancements applied to the treatment of DS. Insights will be useful not only to assess whether speech fluency of people who stutter may be ameliorated acting directly on brain functioning, but they will also provide further suggestions about the complex and dynamic pathophysiology of DS, where causal effects and “adaptive”/”maladaptive” mechanisms of compensation may be strongly overlapping. In conclusion, this review focuses future research toward more specific, targeted, and effective interventions for DS, based on neuromodulation of brain functioning.

中文翻译：

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使用非侵入性大脑刺激提高发育性口吃的言语流畅性：来自现有证据的见解


发育性口吃（DS）是一种正常言语节奏的紊乱，在受影响最严重的情况下可能会导致非常虚弱。 DS 的干预历来基于言语模式的行为改变（例如通过言语治疗），有助于恢复更好的言语流利度。然而，通常观察到干预结果存在很大差异，并且目前没有明确的证据可以解决口吃问题，特别是当口吃在成年期持续存在时。在过去的几十年里，DS 越来越被认为是一种功能障碍，影响复杂运动序列（例如语音）的正确编程。同时，由于神经影像学和能够与神经组织功能相互作用的技术（例如非侵入性脑刺激 -NIBS-），对 DS 神经生理学基础的理解也得到了显着提高。在这种情况下，皮质-基底-丘脑-皮质网络的功能失调以及连接模式的缺陷似乎发挥了关键作用，尤其是在感觉运动网络中。因此，直接作用于“有缺陷”或“受损”的大脑回路的功能可能会帮助口吃的人更好地控制流利障碍。这也可能“增强”可用的干预措施，从而有利于言语流畅性的更稳定的结果。通过使用 NIBS 来实现调节（和改善）口吃者大脑功能的尝试正在迅速增加。在这里，我们将回顾这些应用于 DS 治疗的最新进展。 这些见解不仅有助于评估口吃者的言语流畅性是否可以直接通过大脑功能得到改善，而且还将为 DS 复杂且动态的病理生理学提供进一步的建议，其中因果效应和“适应性”/“适应不良”补偿机制可能存在严重重叠。总之，本综述将未来的研究重点放在基于大脑功能神经调节的更具体、更有针对性和更有效的 DS 干预措施上。