Neef Nicole E, Primaßin Annika, von Gudenberg Alexander Wolff, Dechent Peter, Riedel Heiner Christian, Paulus Walter, Sommer Martin
Department of Clinical Neurophysiology, Georg August University, Göttingen, Göttingen 37075, Germany.
Department of Diagnostic and Interventional Neuroradiology, Georg August University, Göttingen 37075, Germany.
Brain Commun. 2021 Jan 5;3(2):fcaa232. doi: 10.1093/braincomms/fcaa232. eCollection 2021.
Recent studies have identified two distinct cortical representations of voice control in humans, the ventral and the dorsal laryngeal motor cortex. Strikingly, while persistent developmental stuttering has been linked to a white-matter deficit in the ventral laryngeal motor cortex, intensive fluency-shaping intervention modulated the functional connectivity of the dorsal laryngeal motor cortical network. Currently, it is unknown whether the underlying structural network organization of these two laryngeal representations is distinct or differently shaped by stuttering intervention. Using probabilistic diffusion tractography in 22 individuals who stutter and participated in a fluency shaping intervention, in 18 individuals who stutter and did not participate in the intervention and in 28 control participants, we here compare structural networks of the dorsal laryngeal motor cortex and the ventral laryngeal motor cortex and test intervention-related white-matter changes. We show (i) that all participants have weaker ventral laryngeal motor cortex connections compared to the dorsal laryngeal motor cortex network, regardless of speech fluency, (ii) connections of the ventral laryngeal motor cortex were stronger in fluent speakers, (iii) the connectivity profile of the ventral laryngeal motor cortex predicted stuttering severity (iv) but the ventral laryngeal motor cortex network is resistant to a fluency shaping intervention. Our findings substantiate a weaker structural organization of the ventral laryngeal motor cortical network in developmental stuttering and imply that assisted recovery supports neural compensation rather than normalization. Moreover, the resulting dissociation provides evidence for functionally segregated roles of the ventral laryngeal motor cortical and dorsal laryngeal motor cortical networks.
最近的研究已经确定了人类语音控制在皮质上的两种不同表征，即腹侧和背侧喉运动皮质。引人注目的是，虽然持续性发育性口吃与腹侧喉运动皮质的白质缺陷有关，但强化流畅性塑造干预可调节背侧喉运动皮质网络的功能连接。目前尚不清楚这两种喉部表征的潜在结构网络组织是否不同，或者是否会因口吃干预而呈现不同的形态。我们对22名口吃且参加了流畅性塑造干预的个体、18名口吃但未参加干预的个体以及28名对照参与者进行了概率性扩散张量成像，在此比较背侧喉运动皮质和腹侧喉运动皮质的结构网络，并测试与干预相关的白质变化。我们发现：（i）无论言语流畅性如何，所有参与者腹侧喉运动皮质的连接相对于背侧喉运动皮质网络都较弱；（ii）流利说话者腹侧喉运动皮质的连接更强；（iii）腹侧喉运动皮质的连接特征可预测口吃严重程度；（iv）但腹侧喉运动皮质网络对流畅性塑造干预具有抗性。我们的研究结果证实了发育性口吃中腹侧喉运动皮质网络的结构组织较弱，并表明辅助恢复支持神经补偿而非正常化。此外，由此产生的分离为腹侧喉运动皮质网络和背侧喉运动皮质网络在功能上的不同作用提供了证据。
