Therapy-related reorganization of language in both hemispheres of patients with chronic aphasia
Therapy-related reorganization of language in both hemispheres of patients with chronic aphasia
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DOI：
10.1016/j.neuroimage.2005.06.038
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发表时间：
2005-11-01
期刊：
影响因子：
5.7
通讯作者：
Mohr, B
中科院分区：
文献类型：
--
作者：
Pulvermüller, F;Hauk, O;Mohr, B
人们对中风后语言恢复的大脑过程知之甚少，部分原因是过去的研究不允许区分自发恢复过程和与学习相关的皮质重组的影响。在这里，我们使用了最近发展起来的强化神经心理疗法提供的一种新方法，这种方法允许在短时间内改善语言功能。患有慢性失语症的中风患者接受了为期两周的高强度语言治疗，在此期间，通过临床测试评估，他们的语言表现有所改善。观察治疗前后词和假词诱发的神经生理活动。在治疗间隔期间，早期词诱发电位(潜伏期250300毫秒)显著增强，而假词反应没有变化。通过对事件相关电位幅度和均方根值的分析，记录了特定单词的变化，这揭示了因素评估时间(治疗前和治疗后)和词性(单词和假词)的交互作用。基于最小范数电流估计的源定位表明，词刺激激活的双侧皮层源对这种变化有贡献，这表明分布在两个半球的神经元网络是强烈失语治疗中语言处理的皮质重组的底物。单词诱发的来源强度差异与临床语言测试的表现显著相关，这表明行为变化和神经生理变化之间存在联系。我们认为，早期的词诱发负波可能代表卒中后语言重组的一个指标，因此是失语症恢复潜力的一个指标。
The brain processes of language recovery after stroke are poorly understood, partly because past research did not allow to differentiate the effects of spontaneous restitution processes from those of learning-related cortical reorganization. Here, we use a new approach offered by recently developed intense neuropsychological therapy methods, which allow for improving language functions within a short time period. Stroke patients with chronic aphasia received intense language therapy for 2 weeks and, over this period, improved their language performance as assessed using clinical tests. Neurophysiological activity elicited by words and pseudowords was measured before and after treatment. Over the therapy interval, early word evoked potentials (latency 250300 ms) became significantly stronger whereas pseudoword responses did not change. Word-specific changes were documented by analyses of ERP amplitudes and root mean square values, which revealed interactions of the factors Assessment time (before vs. after therapy) and Wordness (word vs. pseudoword). Source localization using Minimum Norm Current Estimates showed that bilateral cortical sources activated by word stimuli contributed to the change, suggesting that neuronal networks distributed over both hemispheres are the substrate of cortical reorganization of language processing in intense aphasia therapy. Word-evoked differences in source strengths were significantly correlated with performance on a clinical language test, demonstrating a link between behavioral and neurophysiological changes. We suggest that the early word-evoked negativity might represent an index of reorganization of language after stroke and thus an aphasia recovery potential.