Several investigations have shown language impairments following electrode implantation surgery for Deep Brain Stimulation (DBS) in movement disorders. The impact of the actual stimulation, however, differs between DBS targets with further deterioration in formal language tests induced by thalamic DBS in contrast to subtle improvement observed in subthalamic DBS. Here, we studied speech samples from interviews with participants treated with DBS of the thalamic ventral intermediate nucleus (VIM) for essential tremor, or the subthalamic nucleus (STN) for Parkinson’s disease, and healthy volunteers (each n = 13). We analyzed word frequency and the use of open and closed class words. Active DBS increased word frequency in case of VIM, but not STN stimulation. Further, relative to controls, both DBS groups produced fewer open class words. Whereas VIM DBS further decreased the proportion of open class words, it was increased by STN DBS. Thus, VIM DBS favors the use of relatively common words in spontaneous language, compatible with the idea of lexical simplification under thalamic stimulation. The absence or even partial reversal of these effects in patients receiving STN DBS is of interest with respect to biolinguistic concepts suggesting dichotomous thalamic versus basal ganglia roles in language processing.

中文翻译：

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丘脑而非丘脑神经调节可简化自发语言中的单词使用

多项研究表明，电极植入手术后因运动障碍引起的深部脑刺激（DBS）出现语言障碍。但是，实际刺激的影响在DBS目标之间是不同的，与在丘脑DBS中观察到的细微改善相反，由丘脑DBS引起的正式语言测试进一步恶化。在这里，我们研究了访谈对象的言语样本，这些访谈对象是接受丘脑腹侧中间核（VIM）的DBS治疗帕金森氏病或丘脑下核（STN）的参与者以及健康志愿者（每个n = 13）。我们分析了词频以及开放和封闭类词的使用。在VIM的情况下，主动DBS会增加单词频率，但不会刺激STN。此外，相对于控件，两个DBS组产生的开放类单词更少。VIM DBS进一步降低了公开课单词的比例，而STN DBS则提高了该比例。因此，VIM DBS支持在自发语言中使用相对常见的单词，这与在丘脑刺激下简化词汇的想法兼容。就暗示在语言加工中丘脑与基底神经节作用的二语性生物语言概念而言，在接受STN DBS的患者中这些作用的缺失甚至是部分逆转是令人感兴趣的。