Al Harrach Mariam, Rousseau François, Groeschel Samuel, Chabrier Stéphane, Hertz-Pannier Lucie, Lefevre Julien, Dinomais Mickael
Laboratoire Angevin de Recherche en Ingénierie des Systèmes (LARIS) EA7315, Université d'Angers, Polytech Angers, Angers, France.
INSERM U1101 LaTIM, UBL, IMT Atlantique, Brest, France.
Front Hum Neurosci. 2020 Apr 29;14:154. doi: 10.3389/fnhum.2020.00154. eCollection 2020.
Functional MRI is increasingly being used in the assessment of brain activation and connectivity following stroke. Many of these studies rely on the Blood Oxygenation Level Dependent (BOLD) contrast. However, the stability, as well as the accuracy of the BOLD response to motor task in the ipsilesional hemisphere, remains ambiguous. In this work, the BOLD signal acquired from both healthy and affected hemispheres was analyzed in 7-year-old children who sustained a Neonatal Arterial Ischemic Stroke (NAIS). Accordingly, a repetitive motor task of the contralesional and the ipsilesional hands was performed by 33 patients with unilateral lesions. These patients were divided into two groups: those without cerebral palsy (NAIS), and those with cerebral palsy (CP). The BOLD signal time course was obtained from distinctly defined regions of interest (ROIs) extracted from the functional activation maps of 30 healthy controls with similar age and demographic characteristics as the patients. An ROI covering both the primary motor cortex (M1) and the primary somatosensory cortex (S1) was also tested. Compared with controls, NAIS patients without CP had similar BOLD amplitude variation for both the contralesional and the ipsilesional hand movements. However, in the case of NAIS patients with CP, a significant difference in the averaged BOLD amplitude was found between the healthy and affected hemisphere. In both cases, no progressive attenuation of the BOLD signal amplitude was observed throughout the task epochs. Besides, results also showed a correlation between the BOLD signal percentage variation of the lesioned hemisphere and the dexterity level. These findings suggest that for patients who sustained a NAIS with no extensive permanent motor impairment, BOLD signal-based data analysis can be a valuable tool for the evaluation of functional brain networks.
功能磁共振成像（Functional MRI）越来越多地用于评估中风后脑激活和连接情况。这些研究中的许多都依赖于血氧水平依赖（BOLD）对比。然而，同侧半球对运动任务的BOLD反应的稳定性以及准确性仍不明确。在这项研究中，对7岁时发生新生儿动脉缺血性卒中（NAIS）的儿童的健康半球和患侧半球采集的BOLD信号进行了分析。因此，33例单侧病变患者进行了对侧手和同侧手的重复性运动任务。这些患者被分为两组：无脑瘫的患者（NAIS）和有脑瘫的患者（CP）。BOLD信号时间进程是从与患者年龄和人口统计学特征相似的30名健康对照的功能激活图中提取的明确界定的感兴趣区域（ROI）获得的。还测试了一个覆盖初级运动皮层（M1）和初级体感皮层（S1）的ROI。与对照组相比，无CP的NAIS患者对侧手和同侧手运动的BOLD幅度变化相似。然而，对于有CP的NAIS患者，在健康半球和患侧半球之间发现平均BOLD幅度存在显著差异。在这两种情况下，在整个任务时段均未观察到BOLD信号幅度的逐渐衰减。此外，结果还显示病变半球的BOLD信号百分比变化与灵巧程度之间存在相关性。这些发现表明，对于没有广泛永久性运动障碍的NAIS患者，基于BOLD信号的数据分析可能是评估功能性脑网络的有价值工具。
