Division of Physiological Psychology and/or Laboratory for Sleep and Consciousness Research, Department of Psychology, University of Salzburg, Hellbrunnerstraße 34, 5020 Salzburg, Austria.
J Neurol. 2013 Sep;260(9):2348-56. doi: 10.1007/s00415-013-6982-3. Epub 2013 Jun 14.
Patients suffering from disorders of consciousness still present a diagnostic challenge due to the fact that their assessment is mainly based on behavioral scales with their motor responses often being strongly impaired. We therefore focused on resting electroencephalography (EEG) in order to reveal potential alternative measures of the patient's current state independent of rather complex abilities (e.g., language comprehension). Resting EEG was recorded in nine minimally conscious state (MCS) and eight vegetative state/unresponsive wakefulness syndrome (VS/UWS) patients. Behavioral assessments were conducted using the Coma-Recovery Scale-Revised (CRS-R). The signal was analyzed in the frequency domain and association between resting EEG and CRS-R score as well as clinical diagnosis were calculated using Pearson correlation and repeated-measures ANOVAs. The analyses revealed robust positive correlations between CRS-R score and ratios between frequencies above 8 Hz and frequencies below 8 Hz. Furthermore, the frequency of the spectral peak was also highly indicative of the patient's CRS-R score. Concerning differences between clinical diagnosis and healthy controls, it could be revealed that while VS/UWS patients showed higher delta and theta activity than controls, MCS did not differ from controls in this frequency range. Alpha activity, on the other hand, was strongly decreased in both patient groups as compared to controls. The strong relationship between various resting EEG parameters and CRS-R score provides significant clinical relevance. Not only is resting activity easily acquired at bedside, but furthermore, it does not depend on explicit cooperation of the patient. Especially in cases where behavioral assessment is difficult or ambiguous, spectral analysis of resting EEG can therefore complement clinical diagnosis.
由于意识障碍患者的评估主要基于行为量表，且其运动反应通常受到严重损害，因此他们的诊断仍然具有挑战性。我们因此专注于静息脑电图（EEG），以揭示患者当前状态的潜在替代指标，这些指标独立于相当复杂的能力（例如语言理解）。在九位最小意识状态（MCS）和八位植物状态/无反应性觉醒综合征（VS/UWS）患者中记录静息 EEG。使用昏迷恢复量表修订版（CRS-R）进行行为评估。对信号进行频域分析，并使用 Pearson 相关和重复测量 ANOVA 计算静息 EEG 与 CRS-R 评分之间的关联以及临床诊断。分析显示 CRS-R 评分与 8 Hz 以上和 8 Hz 以下频率之间的比值之间存在强正相关。此外，频谱峰值的频率也高度表明患者的 CRS-R 评分。关于临床诊断与健康对照组之间的差异，可以发现 VS/UWS 患者的 delta 和 theta 活动高于对照组，而 MCS 在该频率范围内与对照组没有差异。另一方面，与对照组相比，两个患者组的 alpha 活动均明显降低。各种静息 EEG 参数与 CRS-R 评分之间的强关系提供了显著的临床相关性。静息活动不仅易于在床边获得，而且它不依赖于患者的明确合作。特别是在行为评估困难或不明确的情况下，静息 EEG 的频谱分析因此可以补充临床诊断。
