静息态fMRI联合DTI对rTMS干预亚急性期完全性失语症功能连接和结构连接的机制研究

Aphasia is one of the most feared symptoms of stroke. The first 1 to 3 months after stroke are crucial for language recovery. While regular speech-language therapy is the most commonly employed treatment of aphasia, its therapeutic effects are quite variable and are generally modest. Recently, repetitive transcranial magnetic stimulation (rTMS) has shown promise as potential approaches for enhancing aphasia recovery. A number of research studies employing low frequency rTMS, on the site of right pars triangularis of inferior frontal gyrus have reported lasting improvement in specific language functions in patients with chronic post-stroke aphasia, which underlying mechanism is induced cortical reorganization of language functions to the left hemisphere relate to the improvements after therapeutic rTMS. Our pilot study has found that low frequency rTMS on the right posterior superior temporal gyrus (STG) benefit comprehension language recovery for subacute post-stroke global aphasia. Application of functional connectivity (resting-fMRI) and structural connectivity (diffusion tensor imaging (DTI)) for the neuroplasticity mechanism of rTMS on global aphasia has not yet been reported. The aim of the present randomized, blinded, and sham-controlled proof-of-principle study is to compare the outcome to the effect of low frequency rTMS on the right posterior STG in subacute global aphasia and its possible mechanism from combined with functional connection and structural connection by resting-fMRI and DTI.

失语症是脑卒中常见的临床表现之一。亚急性期是失语症恢复的关键时期，完全性失语症常规言语训练疗效有限。左侧优势半球残留语言网络重组是失语症恢复的有效机制，而亚急性期右脑语言等位区异常激活不利于言语恢复。目前非侵入性脑刺激技术rTMS被认为是一种有潜力的失语症治疗手段，既往研究多关注低频rTMS抑制右侧额下回三角部改善失语症的言语表达及命名能力，可能与其抑制右脑过度激活脑区促进左脑残留语言网络的重建有关。我们的预实验初步发现rTMS抑制右侧颞上回后部改善完全性失语症的听理解。尚未有研究联合静息态fMRI和DTI探讨rTMS干预完全性失语症的神经重塑机制。本课题拟采用随机对照研究联合静息态fMRI和DTI对完全性失语症进行rTMS干预前后及假刺激组的对比分析，进行语言相关脑区之间功能连接和结构连接的数据分析，揭示低频rTMS干预完全性失语症的疗效及其神经重塑机制，为失语症的治疗提供理论依据。

rTMS刺激不同部位对脑卒中完全性失语症患者的言语功能影响及其机制仍不明确。本研究采用随机对照研究联合静息态fMRI对完全性失语症进行rTMS干预前后及假刺激组的对比分析，进行语言相关脑区之间功能连接的数据分析。并探究完全性失语症患者与正常对照大脑自发性活动的差异。结果提示亚急性期完全性失语症患者的神经恢复机制仍以右侧大脑半球代偿为主。低频rTMS抑制右侧额下回三角部和右侧颞上回后部均能改善完全性失语症患者的言语功能。低频rTMS抑制右侧颞上回后部能改善完全性失语症患者的听理解和复述能力，而右侧额下回三角部能改善完全性失语症患者的自发言语和复述能力，其疗效可能与刺激部位有关。rTMS治疗后以右侧额下回、右侧颞上回和右侧颞中回自发活动增多，提示仍以右侧大脑半球代偿为主,为rTMS干预完全性失语症的治疗提供理论依据。