From the Division of Neurocritical Care, Department of Neurology, (S.B.S., D.F., M.E.M., M.B.B.), Departments of Neurology, Psychiatry, and Radiology (A.L.C., F.L.W.V.J.S., M.D.F.), Center for Brain Circuit Therapeutics, Division of Cardiology, Department of Medicine (B.S.), and Division of Epilepsy, Department of Neurology (J.W.L.), Brigham and Women's Hospital, Harvard Medical School; Departments of Neurology and Radiology (A.L.C.), Computational Radiology Laboratory, Boston Children's Hospital, Harvard Medical School, MA; Department of Neurology (E.A.), Weill Institute for Neurosciences, University of California at San Francisco; Neurology Service (E.A.), Zuckerberg San Francisco General Hospital, CA; Departments of Neurology and Radiology (M.D.F.), Athinoula A. Martinos Centre for Biomedical Imaging, Massachusetts General Hospital, Charlestown; and Department of Neurology (M.D.F.), Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA.
Neurology. 2022 Mar 22;98(12):e1238-e1247. doi: 10.1212/WNL.0000000000013301. Epub 2022 Jan 11.
Disorders of consciousness, EEG background suppression, and epileptic seizures are associated with poor outcome after cardiac arrest. Our objective was to identify the distribution of diffusion MRI-measured anoxic brain injury after cardiac arrest and to define the regional correlates of disorders of consciousness, EEG background suppression, and seizures.
We analyzed patients from a single-center database of unresponsive patients who underwent diffusion MRI after cardiac arrest (n = 204). We classified each patient according to recovery of consciousness (command following) before discharge, the most continuous EEG background (burst suppression vs continuous), and the presence or absence of seizures. Anoxic brain injury was measured with the apparent diffusion coefficient (ADC) signal. We identified ADC abnormalities relative to controls without cardiac arrest (n = 48) and used voxel lesion symptom mapping to identify regional associations with disorders of consciousness, EEG background suppression, and seizures. We then used a bootstrapped lasso regression procedure to identify robust, multivariate regional associations with each outcome variable. Last, using area under receiver operating characteristic curves, we then compared the classification ability of the strongest regional associations to that of brain-wide summary measures.
Compared to controls, patients with cardiac arrest demonstrated ADC signal reduction that was most significant in the occipital lobes. Disorders of consciousness were associated with reduced ADC most prominently in the occipital lobes but also in deep structures. Regional injury more accurately classified patients with disorders of consciousness than whole-brain injury. Background suppression mapped to a similar set of brain regions, but regional injury could no better classify patients than whole-brain measures. Seizures were less common in patients with more severe anoxic injury, particularly in those with injury to the lateral temporal white matter.
Anoxic brain injury was most prevalent in posterior cerebral regions, and this regional pattern of injury was a better predictor of disorders of consciousness than whole-brain injury measures. EEG background suppression lacked a specific regional association, but patients with injury to the temporal lobe were less likely to have seizures. Regional patterns of anoxic brain injury are relevant to the clinical and electrographic sequelae of cardiac arrest and may hold importance for prognosis.
This study provides Class IV evidence that disorders of consciousness after cardiac arrest are associated with widely lower ADC values on diffusion MRI and are most strongly associated with reductions in occipital ADC.
意识障碍、脑电图背景抑制和癫痫发作与心脏骤停后预后不良有关。我们的目的是确定心脏骤停后弥散 MRI 测量的缺氧性脑损伤的分布，并确定与意识障碍、脑电图背景抑制和癫痫发作相关的区域相关性。
我们分析了来自单一中心数据库中无反应患者的患者数据，这些患者在心脏骤停后接受了弥散 MRI 检查（n = 204）。我们根据出院前意识恢复情况（听从指令）、最连续的脑电图背景（爆发抑制与连续）以及是否存在癫痫发作对每位患者进行分类。用表观扩散系数（ADC）信号测量缺氧性脑损伤。我们将 ADC 异常与无心脏骤停的对照组（n = 48）进行了比较，并使用体素病变症状映射来识别与意识障碍、脑电图背景抑制和癫痫发作相关的区域相关性。然后，我们使用 bootstrap 套索回归程序来识别与每个结果变量具有稳健、多变量区域相关性的变量。最后，使用接收器操作特征曲线下面积，我们比较了最强区域相关性的分类能力与脑广泛总结指标的分类能力。
与对照组相比，心脏骤停患者的 ADC 信号降低，在枕叶最为明显。意识障碍与枕叶 ADC 降低最为明显，但也与深部结构有关。区域损伤比全脑损伤更能准确地分类意识障碍患者。背景抑制映射到一组相似的脑区，但与全脑测量相比，区域损伤不能更好地对患者进行分类。与缺氧损伤更严重的患者相比，癫痫发作较少见，尤其是在外侧颞叶白质损伤的患者中。
缺氧性脑损伤最常见于后脑区域，这种区域性损伤模式比全脑损伤测量更能预测意识障碍。脑电图背景抑制缺乏特定的区域相关性，但颞叶损伤的患者更不可能发生癫痫。缺氧性脑损伤的区域性模式与心脏骤停后的临床和脑电图后遗症相关，可能对预后有重要意义。
这项研究提供了 IV 级证据，表明心脏骤停后意识障碍与弥散 MRI 上广泛降低的 ADC 值相关，与枕叶 ADC 降低的相关性最强。
