Coleman M R, Davis M H, Rodd J M, Robson T, Ali A, Owen A M, Pickard J D
Impaired Consciousness Study Group, Wolfson Brain Imaging Centre, Addenbrookes Hospital, University of Cambridge, Cambridge, UK.
Brain. 2009 Sep;132(Pt 9):2541-52. doi: 10.1093/brain/awp183.
Clinical audits have highlighted the many challenges and dilemmas faced by clinicians assessing persons with disorders of consciousness (vegetative state and minimally conscious state). The diagnostic decision-making process is highly subjective, dependent upon the skills of the examiner and invariably dictated by the patients' ability to move or speak. Whilst a considerable amount has been learnt since Jennett and Plum coined the term 'vegetative state', the assessment process remains largely unchanged; conducted at the bedside, using behavioural assessment tools, which are susceptible to environmental and physiological factors. This has created a situation where the rate of misdiagnosis is unacceptably high (up to 43%). In order to address these problems, various functional brain imaging paradigms, which do not rely upon the patient's ability to move or speak, have been proposed as a source of additional information to inform the diagnostic decision making process. Although accumulated evidence from brain imaging, particularly functional magnetic resonance imaging (fMRI), has been encouraging, the empirical evidence is still based on relatively small numbers of patients. It remains unclear whether brain imaging is capable of informing the diagnosis beyond the behavioural assessment and whether brain imaging has any prognostic utility. In this study, we describe the functional brain imaging findings from a group of 41 patients with disorders of consciousness, who undertook a hierarchical speech processing task. We found, contrary to the clinical impression of a specialist team using behavioural assessment tools, that two patients referred to the study with a diagnosis of vegetative state did in fact demonstrate neural correlates of speech comprehension when assessed using functional brain imaging. These fMRI findings were found to have no association with the patient's behavioural presentation at the time of investigation and thus provided additional diagnostic information beyond the traditional clinical assessment. Notably, the utility of brain imaging was further underlined by the finding that the level of auditory processing revealed by functional brain imaging, correlated strongly (rs = 0.81, P < 0.001) with the patient's subsequent behavioural recovery, 6 months after the scan, suggesting that brain imaging may also provide valuable prognostic information. Although further evidence is required before consensus statements can be made regarding the use of brain imaging in clinical decision making for disorders of consciousness, the results from this study clearly highlight the potential of imaging to inform the diagnostic decision-making process for persons with disorders of consciousness.
临床审计突出了临床医生在评估意识障碍（植物状态和微意识状态）患者时面临的诸多挑战和困境。诊断决策过程高度主观，取决于检查者的技能，并且总是由患者的运动或说话能力决定。自从珍妮特和普拉姆创造了“植物状态”这个术语以来，虽然已经学到了很多东西，但评估过程在很大程度上仍未改变；在床边进行，使用行为评估工具，这些工具容易受到环境和生理因素的影响。这就造成了误诊率高得令人无法接受（高达43%）的情况。为了解决这些问题，人们提出了各种不依赖患者运动或说话能力的功能性脑成像范式，作为为诊断决策过程提供额外信息的来源。尽管来自脑成像，特别是功能磁共振成像（fMRI）的累积证据令人鼓舞，但实证证据仍然基于相对较少的患者数量。目前尚不清楚脑成像是否能够在行为评估之外为诊断提供信息，以及脑成像是否具有任何预后效用。在这项研究中，我们描述了一组41名意识障碍患者在进行分层语音处理任务时的功能性脑成像结果。我们发现，与使用行为评估工具的专家团队的临床印象相反，两名被转诊到该研究且诊断为植物状态的患者，在使用功能性脑成像进行评估时，实际上表现出了言语理解的神经关联。这些fMRI结果被发现与患者在检查时的行为表现无关，因此提供了超越传统临床评估的额外诊断信息。值得注意的是，功能性脑成像揭示的听觉处理水平与扫描6个月后患者随后的行为恢复密切相关（rs = 0.81，P < 0.001），这一发现进一步强调了脑成像的效用，表明脑成像也可能提供有价值的预后信息。虽然在就脑成像在意识障碍临床决策中的使用达成共识声明之前还需要进一步的证据，但这项研究的结果清楚地突出了成像在为意识障碍患者的诊断决策过程提供信息方面的潜力。
