Young G B
Department of Clinical Neurological Sciences, The University of Western Ontario, London, Ontario, Canada.
J Clin Neurophysiol. 2000 Sep;17(5):473-85. doi: 10.1097/00004691-200009000-00006.
The EEG allows insight into thalamocortical function in comatose patients when this is inaccessible clinically. A single EEG can help with broad diagnostic categorization whereas continuous or serial EEG provides monitoring for unstable and potentially treatable conditions and for monitoring the effects of therapy. The EEG plays a supplemental role in establishing the prognosis in disease states that are capable of causing neuronal death. The most prevalent and problematic of these conditions involves survivors of cardiac arrest who are initially in coma with intact brainstem reflexes. In such patients single EEGs are of 100% specificity for no possibility of recovery of consciousness only for essentially complete generalized suppression (<10 microV) after the first day of the arrest. Several other generalized patterns, including less marked suppression, burst-suppression, epileptiform activity, periodic complexes, and alpha-theta coma patterns, usually but not invariably indicate a poor outcome. Serial EEGs, continuous raw and automated "trending," testing of reactivity, and the inclusion of multiple variables hold promise for an improved role in the prognostic determination in these patients.
脑电图能够在临床上无法获取相关信息时，洞察昏迷患者的丘脑皮质功能。单次脑电图有助于进行广泛的诊断分类，而连续或系列脑电图则可对不稳定且可能可治疗的病情进行监测，并监测治疗效果。脑电图在能够导致神经元死亡的疾病状态下确定预后方面发挥着辅助作用。其中最常见且成问题的情况涉及心脏骤停幸存者，他们最初处于昏迷状态，但脑干反射完整。在此类患者中，仅在心脏骤停第一天后出现基本完全性广泛性抑制（<10微伏）时，单次脑电图对于意识无法恢复的特异性为100%。其他几种广泛性模式，包括不太明显的抑制、爆发抑制、癫痫样活动、周期性复合波以及α-θ昏迷模式，通常但并非总是预示着不良预后。系列脑电图、连续原始及自动“趋势分析”、反应性测试以及纳入多个变量，有望在这些患者的预后判定中发挥更大作用。
