JAMA Neurol. 2013 Oct;70(10):1235-41. doi: 10.1001/jamaneurol.2013.3686.
Despite the apparent absence of external signs of consciousness, a significant small proportion of patients with disorders of consciousness can respond to commands by willfully modulating their brain activity, even respond to yes or no questions, by performing mental imagery tasks. However, little is known about the mental life of such responsive patients, for example, with regard to whether they can have coherent thoughts or selectively maintain attention to specific events in their environment. The ability to selectively pay attention would provide evidence of a patient's preserved cognition and a method for brain-based communication, thus far untested with functional magnetic resonance imaging in this patient group.
To test whether selective auditory attention can be used to detect conscious awareness and communicate with behaviorally nonresponsive patients.
DESIGN, SETTING, AND PARTICIPANTS: Case study performed in 3 patients with severe brain injury, 2 diagnosed as being in a minimally conscious state and 1 as being in a vegetative state. The patients constituted a convenience sample.
Functional magnetic resonance imaging data were acquired as the patients were asked to selectively attend to auditory stimuli, thereby conveying their ability to follow commands and communicate.
All patients demonstrated command following according to instructions. Two patients (1 in a minimally conscious state and 1 in a vegetative state) were also able to guide their attention to repeatedly communicate correct answers to binary (yes or no) questions.
To our knowledge, we show for the first time with functional magnetic resonance imaging that behaviorally nonresponsive patients can use selective auditory attention to convey their ability to follow commands and communicate. One patient in a minimally conscious state was able to use attention to establish functional communication in the scanner, despite his inability to produce any communication responses in repeated bedside examinations. More important, 1 patient, who had been in a vegetative state for 12 years before the scanning and subsequent to it, was able to use attention to correctly communicate answers to several binary questions. The technique may be useful in establishing basic communication with patients who appear unresponsive to bedside examinations and cannot respond with existing neuroimaging methods.
尽管意识障碍患者表面上没有外部意识迹象，但一小部分患者可以通过有意调节大脑活动来响应命令，甚至可以通过执行心理意象任务来回答是或否的问题。然而，对于这些有反应的患者的精神生活，我们知之甚少，例如，他们是否能够有连贯的想法，或者选择性地关注环境中的特定事件。选择性注意的能力将提供患者认知能力保存的证据，以及一种基于大脑的交流方法，迄今为止，在这个患者群体中，还没有使用功能磁共振成像进行测试。
测试选择性听觉注意力是否可用于检测意识并与行为无反应的患者进行交流。
设计、地点和参与者：在 3 名严重脑损伤患者中进行病例研究，其中 2 名被诊断为处于最小意识状态，1 名处于植物状态。患者构成了便利样本。
当患者被要求选择性地注意听觉刺激时，采集功能磁共振成像数据，从而传达他们听从命令和交流的能力。
所有患者均根据指令进行了命令跟随。两名患者（1 名处于最小意识状态，1 名处于植物状态）也能够指导他们的注意力，反复传达对二进制（是或否）问题的正确答案。
据我们所知，我们首次使用功能磁共振成像显示，行为无反应的患者可以使用选择性听觉注意力传达他们听从命令和交流的能力。一名处于最小意识状态的患者尽管在多次床边检查中无法产生任何交流反应，但仍能够使用注意力在扫描仪中建立功能交流。更重要的是，在扫描和随后的 12 年中，一名处于植物状态的患者能够使用注意力正确回答几个二进制问题。该技术可能有助于与对床边检查无反应且无法使用现有神经影像学方法做出反应的患者建立基本交流。
