Electrical stimulation of the motor cortex enhances treatment outcome in post-stroke aphasia
Electrical stimulation of the motor cortex enhances treatment outcome in post-stroke aphasia
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DOI：
10.1093/brain/aww002
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发表时间：
2016-04-01
期刊：
影响因子：
14.5
通讯作者：
Floeel, Agnes
中科院分区：
文献类型：
--
作者：
Meinzer, Marcus;Darkow, Robert;Floeel, Agnes
经颅直流电刺激已显示出改善卒中后失语患者恢复的前景，但以前的研究仅评估了刺激对损伤参数的影响，缺乏随机对照试验长期维持经颅直流电刺激效果的证据。此外，由于中风后病变和功能语言网络重组的变异性，最近的研究使用先进的功能成像或当前建模来确定个体患者的最佳刺激部位。然而，这种方法是昂贵的，耗时的，并且在专业研究中心之外可能是不可行的，这使得经颅直流电刺激在日常临床实践中的结合变得复杂。刺激一个在功能上与剩余语言网络相连接的辅助系统，即初级运动系统，将更容易适用，但这种方法的有效性尚未得到系统的探讨。我们进行了一项随机、平行组、假对照、双盲临床试验，26例慢性失语症患者接受了为期2周的高强度命名治疗（8天，2 x 1.5小时/天）。同时，在每次训练开始时，每天两次对左侧初级运动皮质进行阳极经颅直流电刺激。在干预后立即和6个月后评估了训练项目（n = 60张图片，在重复基线评估期间无法命名）的可扩展性，转移到未训练项目（n = 284张图片）和泛化到日常交流。在阳极（Cohen's d = 3.67）和假经颅直流电刺激组（d = 2.10）中，训练项目的可识别性在干预结束后立即得到显著改善，阳极经颅直流电刺激组（d = 0.71）有较大增益的趋势。6个月后，阳极-经颅直流电刺激组对训练项目的治疗效果明显更好（d = 1.19）。在培训后（d = 1.49）和6个月随访评估期间（d = 3.12），阳极-经颅直流电刺激组转移到未培训项目的比例显著更大。转移效应仅在阳极-经颅直流电刺激组中维持。与假经颅直流电刺激治疗的患者相比，阳极经颅直流电刺激组在两个时间点的功能性沟通得到了显著改善（d = 0.75-0.99）。我们的研究结果提供了来自随机对照试验的第一个证据，即经颅直流电刺激可以改善慢性失语症的功能和活动相关结局，具有中等至大的效应量，并且这些效应可以在很长一段时间内保持。这些效果是通过一种易于实现的，因此在临床上可行的运动皮层蒙太奇来实现的，这可能代表了一种有前途的“后门”方法来改善中风后的语言恢复。
Transcranial direct current stimulation has shown promise to improve recovery in patients with post-stroke aphasia, but previous studies have only assessed stimulation effects on impairment parameters, and evidence for long-term maintenance of transcranial direct current stimulation effects from randomized, controlled trials is lacking. Moreover, due to the variability of lesions and functional language network reorganization after stroke, recent studies have used advanced functional imaging or current modelling to determine optimal stimulation sites in individual patients. However, such approaches are expensive, time consuming and may not be feasible outside of specialized research centres, which complicates incorporation of transcranial direct current stimulation in day-to-day clinical practice. Stimulation of an ancillary system that is functionally connected to the residual language network, namely the primary motor system, would be more easily applicable, but effectiveness of such an approach has not been explored systematically. We conducted a randomized, parallel group, sham-controlled, double-blind clinical trial and 26 patients with chronic aphasia received a highly intensive naming therapy over 2 weeks (8 days, 2 x 1.5 h/day). Concurrently, anodal-transcranial direct current stimulation was administered to the left primary motor cortex twice daily at the beginning of each training session. Naming ability for trained items (n = 60 pictures that could not be named during repeated baseline assessments), transfer to untrained items (n = 284 pictures) and generalization to everyday communication were assessed immediately post-intervention and 6 months later. Naming ability for trained items was significantly improved immediately after the end of the intervention in both the anodal (Cohen's d = 3.67) and sham-transcranial direct current stimulation groups (d = 2.10), with a trend for larger gains in the anodal-transcranial direct current stimulation group (d = 0.71). Treatment effects for trained items were significantly better maintained in the anodal-transcranial direct current stimulation group 6 months later (d = 1.19). Transfer to untrained items was significantly larger in the anodal-transcranial direct current stimulation group after the training (d = 1.49) and during the 6 month follow-up assessment (d = 3.12). Transfer effects were only maintained in the anodal-transcranial direct current stimulation group. Functional communication was significantly more improved in the anodal-transcranial direct current stimulation group at both time points compared to patients treated with sham-transcranial direct current stimulation (d = 0.75-0.99). Our results provide the first evidence from a randomized, controlled trial that transcranial direct current stimulation can improve both function and activity-related outcomes in chronic aphasia, with medium to large effect sizes, and that these effects are maintained over extended periods of time. These effects were achieved with an easy-to-implement and thus clinically feasible motor-cortex montage that may represent a promising 'backdoor' approach to improve language recovery after stroke.