Fischer David B, Truog Robert D
From Harvard Medical School (D.B.F., R.D.T.), Boston, MA; and Boston Children's Hospital (R.D.T.), Boston MA.
Neurology. 2015 Aug 11;85(6):543-8. doi: 10.1212/WNL.0000000000001748. Epub 2015 Jun 17.
Uncertainty in diagnosing disorders of consciousness, and specifically in determining whether consciousness has been lost or retained, poses challenging scientific and ethical questions. Recent neuroimaging-based tests for consciousness have cast doubt on the reliability of behavioral criteria in assessing states of consciousness and generate new questions about the assumptions used in formulating coherent diagnostic criteria. The reflex, a foundational diagnostic tool, offers unique insight into these disorders; behaviors produced by unconscious patients are thought to be purely reflexive, whereas those produced by conscious patients can be volitional. Further investigation, however, reveals that reflexes cannot be reliably distinguished from conscious behaviors on the basis of any generalizable empirical characteristics. Ambiguity between reflexive and conscious behaviors undermines the capacity of the reflex to distinguish between disorders of consciousness and has implications for how these disorders should be conceptualized in future diagnostic criteria.
意识障碍诊断中的不确定性，尤其是在确定意识是否丧失或保留方面，提出了具有挑战性的科学和伦理问题。最近基于神经影像学的意识测试对行为标准在评估意识状态方面的可靠性提出了质疑，并引发了关于制定连贯诊断标准时所采用假设的新问题。反射作为一种基础诊断工具，为这些障碍提供了独特的见解；无意识患者产生的行为被认为是纯粹反射性的，而有意识患者产生的行为则可能是有意志的。然而，进一步的研究表明，基于任何可推广的经验特征，反射都无法与有意识行为可靠地区分开来。反射性和有意识行为之间的模糊性削弱了反射区分意识障碍的能力，并对这些障碍在未来诊断标准中应如何概念化产生了影响。
