Sakatani K, Murata Y, Fukaya C, Yamamoto T, Katayama Y
Department of Neurosurgery, Nihon University School of Medicine, Tokyo, Japan.
Acta Neurochir Suppl. 2003;87:59-62. doi: 10.1007/978-3-7091-6081-7_13.
Clinical applications of blood-oxygenation-level-dependent contrast functional MRI (BOLD-fMRI) have been rapidly moving toward routine non-invasive cortical mapping in the patients with brain disorders. However, it is not yet clear whether the damaged brain shows same cerebral blood oxygenation (CBO) changes during neuronal activation as those in the normal adult. We compared the activation mapping obtained by BOLD-fMRI and the evoked-CBO changes measured by near infrared spectroscopy (NIRS) in normal adults (6 cases) and patients with damaged brain (6 cases of cerebral ischemia and 10 cases of brain tumors in or adjacent to the motor cortex). BOLD-fMRI demonstrated robust activation areas in the primary sensorimotor cortex (PSMC) during contralateral hand grasping tasks in all of the normal adults; however, in the cerebral ischemia (6 cases) and the brain tumors (2 cases), BOLD-fMRI demonstrated only limited activation areas in the PSMC on the lesion side during the task. NIRS demonstrated an increase of focal concentration of oxyhemoglobin and total hemoglobin at the PSMC during the task in all of the normal adults and the patients, indicating the presence of rCBF increase in response to neuronal activation. A focal concentration of deoxyhemoglobin decreased during the task in the normal adults, however, in the patients that showed limited activation areas by BOLD-fMRI, deoxyhemoglobin concentrations increased during the entire course of the task. In summary, the evoked-CBO changes occurring in the damaged brain differed from those in the normal brain. This indicates that BOLD-fMRI may overlook activation areas in the damaged brain.
血氧水平依赖对比功能磁共振成像（BOLD-fMRI）的临床应用已迅速朝着对脑部疾病患者进行常规非侵入性皮质图谱绘制发展。然而，尚不清楚受损大脑在神经元激活过程中是否表现出与正常成年人相同的脑血氧合（CBO）变化。我们比较了正常成年人（6例）以及脑部受损患者（6例脑缺血患者和10例运动皮质内或其附近有脑肿瘤的患者）通过BOLD-fMRI获得的激活图谱和通过近红外光谱（NIRS）测量的诱发CBO变化。在所有正常成年人对侧手部抓握任务期间，BOLD-fMRI在初级感觉运动皮质（PSMC）显示出强烈的激活区域；然而，在脑缺血患者（6例）和脑肿瘤患者（2例）中，任务期间BOLD-fMRI在病变侧的PSMC仅显示出有限的激活区域。NIRS显示，在所有正常成年人和患者的任务期间，PSMC处氧合血红蛋白和总血红蛋白的局部浓度增加，表明存在对神经元激活作出反应的局部脑血流量增加。在正常成年人的任务期间，脱氧血红蛋白的局部浓度降低，然而，在通过BOLD-fMRI显示激活区域有限的患者中，脱氧血红蛋白浓度在整个任务过程中均增加。总之，受损大脑中发生的诱发CBO变化与正常大脑不同。这表明BOLD-fMRI可能会忽略受损大脑中的激活区域。
