OBJECTIVE The objective of this study was to determine the frequency and clinical correlates of different electroencephalographic patterns and their association with clinical outcomes in critically ill patients. SUBJECTS AND METHODS This retrospective cross-sectional study was performed in the Neurology Department of King Fahd Hospital of the University, Kingdom of Saudi Arabia and involved a review and analysis of medical records pertaining to 179 intensive care unit patients who underwent electroencephalography (EEG) in the June to November 2018 period. RESULTS Among the different etiologies, presence of spike and wave or sharp wave (SWs) was associated with encephalitis (P = .01) and large artery stroke (P = .01), whereas markedly attenuated EEG activity (p = .04) and burst suppression (P = .01) were associated with large artery stroke and hypoxic ischemic encephalopathy (HIE), respectively. Generalized theta activity (P = .01) was significantly found in patients of septic encephalopathy, while generalized delta activity (P = .02) and asymmetrical background (P = .04) were significantly associated with traumatic brain injury. Presence of periodic discharges in EEG was significantly associated with more adverse clinical outcomes (P = .001), whereas rhythmic delta activity (RDA) (P = .03), persistent focal slow wave activity (P = .01), and asymmetric background (P = .002) were found in patients who were discharged from hospital with sequelae of current illness. CONCLUSION Certain EEG patterns are associated with particular underlying etiologies like SWs for encephalitis, markedly attenuated EEG activity and burst suppression with large artery stroke and HIE, respectively. Whereas few EEG patterns, including periodic discharges, RDA, persistent focal slow wave activity have some prognostic value in critically ill patients. However, they cannot be used as markers for prognostic assessment of patients without considering other clinical and diagnostic variables. Further larger prospective studies with continuous EEG monitoring with control of confounding factors are needed.

中文翻译：

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重症患者脑电图模式的临床相关性

目的 本研究的目的是确定不同脑电图模式的频率和临床相关性以及它们与危重患者临床结果的关联。对象和方法 本项回顾性横断面研究在沙特阿拉伯王国大学法赫德国王医院神经科进行，涉及对 179 名接受脑电图 (EEG) 的重症监护病房患者的病历进行审查和分析。 2018 年 6 月至 11 月期间。结果 在不同的病因中，棘波和尖波 (SWs) 的存在与脑炎 (P = .01) 和大动脉卒中 (P = .01) 相关，而脑电图活动显着减弱 (p = .04) 和突发抑制（P = . 01) 分别与大动脉卒中和缺氧缺血性脑病 (HIE) 相关。在脓毒性脑病患者中发现广泛的 theta 活动 (P = .01)，而广泛的 delta 活动 (P = .02) 和不对称背景 (P = .04) 与创伤性脑损伤显着相关。EEG 中周期性放电的存在与更不利的临床结果显着相关 (P = .001)，而节律性 delta 活动 (RDA) (P = .03)、持续的局灶性慢波活动 (P = .01) 和不对称背景(P = .002) 出现在因当前疾病而出院的患者中。结论 某些 EEG 模式与特定的潜在病因相关，例如脑炎的 SWs、大动脉卒中和 HIE 分别显着减弱 EEG 活动和爆发抑制。而很少有 EEG 模式，包括周期性放电、RDA、持续局灶性慢波活动对危重患者具有一定的预后价值。然而，在不考虑其他临床和诊断变量的情况下，它们不能用作患者预后评估的标志物。需要进一步更大规模的前瞻性研究，在控制混杂因素的情况下进行连续 EEG 监测。