Department of Anesthesia, The Toronto Western Hospital, University Health Network, and Department of Physiology, University of Toronto, 399 Bathurst Street, 3MC-431, Toronto, Ontario, Canada M5T 2S8.
Stroke. 2011 May;42(5):1261-9. doi: 10.1161/STROKEAHA.110.603225. Epub 2011 Apr 14.
Cerebrovascular reactivity (CVR) is an indicator of cerebral hemodynamics. In adults with cerebrovascular disease, impaired CVR has been shown to be associated with an increased risk of stroke. In children, however, CVR studies are not common. This may be due to the difficulties and risks associated with current CVR study methodologies. We have previously described the application of precise control of end-tidal carbon dioxide partial pressure for CVR studies in adults. Our aim is to report initial observations of CVR studies that were performed as part of a larger observational study regarding investigations in pediatric patients with cerebral vascular disease.
Thirteen patients between the ages of 10 and 16 years (10 with a diagnosis of Moyamoya vasculopathy and 3 with confirmed, or suspected, intracranial vascular stenosis) underwent angiography, MRI, and functional blood oxygen level-dependent MRI mapping of CVR to hypercapnia. The results of the CVR study were then related to both the structural imaging and clinical status.
Sixteen blood oxygen level-dependent MRI CVR studies were performed successfully in 13 consecutive patients. Twelve of the 13 patients with angiographic abnormalities also had CVR deficits in the corresponding downstream vascular territories. CVR deficits were also seen in 8 of 9 symptomatic patients and 2 of the asymptomatic patients. Notably, in patients with abnormalities on angiography, the reductions in CVR extended beyond the ischemic lesions identified with MR structural imaging into normal-appearing brain parenchyma.
This is the first case series reporting blood oxygen level-dependent MRI CVR in children with cerebrovascular disease. CVR studies performed so far provide information regarding hemodynamic compromise, which complements traditional clinical assessment and structural imaging.
脑血管反应性（CVR）是脑血流动力学的一个指标。在患有脑血管疾病的成年人中，已经证明受损的 CVR 与中风风险增加有关。然而，在儿童中，CVR 研究并不常见。这可能是由于当前 CVR 研究方法的困难和风险所致。我们之前描述了精确控制呼气末二氧化碳分压在成人 CVR 研究中的应用。我们的目的是报告作为一项关于脑血管疾病儿科患者研究的更大观察性研究的一部分进行的 CVR 研究的初步观察结果。
13 名年龄在 10 至 16 岁之间的患者（10 名诊断为烟雾病，3 名确诊或疑似颅内血管狭窄）接受了血管造影、MRI 和功能性血氧水平依赖 MRI 映射 CVR 以评估高碳酸血症。然后将 CVR 研究的结果与结构成像和临床状况相关联。
13 名连续患者中的 13 名成功进行了 16 次血氧水平依赖 MRI CVR 研究。13 名存在血管造影异常的患者中有 12 名在相应的下游血管区域也存在 CVR 缺陷。8 名有症状的患者和 2 名无症状患者也存在 CVR 缺陷。值得注意的是，在血管造影异常的患者中，CVR 的降低范围超出了 MR 结构成像所识别的缺血性病变，延伸到正常的脑实质。
这是第一组报告脑血管疾病儿童血氧水平依赖 MRI CVR 的病例系列。迄今为止进行的 CVR 研究提供了有关血液动力学受损的信息，补充了传统的临床评估和结构成像。
