Upper Extremity Motor Impairments and Microstructural Changes in Bulbospinal Pathways in Chronic Hemiparetic Stroke.
Upper Extremity Motor Impairments and Microstructural Changes in Bulbospinal Pathways in Chronic Hemiparetic Stroke.
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DOI：
10.3389/fneur.2017.00257
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发表时间：
2017
影响因子：
3.4
通讯作者：
Dewald JPA
中科院分区：
文献类型：
--
作者：
Owen M;Ingo C;Dewald JPA
在轻偏瘫卒中后，对单个关节的精确、个体化控制常常被高度刻板的多关节运动模式或异常肢体协同作用所取代，这可能对轻偏瘫臂的功能使用产生负面影响。这些协同作用表达的一个假设是对球脊髓通路的依赖性增加，如红核脊髓（RubST）束，尤其是网状脊髓（RetST）束，共同激活肩部、肘部、手腕和手指的多个肌肉。尽管有间接证据支持这一假设在人类中风后，它仍然不清楚它是否是正确的。因此，我们使用高分辨率扩散张量成像（DTI）来量化与手臂协同和手相关运动障碍严重程度相关的白色物质微观结构。对19名中度至重度受损的慢性脑卒中患者和15名年龄匹配的健康对照者进行了DTI检查。在中风患者中，与对照组相比，双侧放射冠和胼胝体体的各向异性分数（FA）显著降低，轴向和径向扩散率显著增加。此外，卒中后，对侧病变（CL）RetST FA与上肢（UE）协同严重程度（r =-0.606，p = 0.003）和手部损伤（r =-0.609，p = 0.003）显著相关。同病灶RubST的FA与手部损伤严重程度显著相关（r =-0.590，p = 0.004）。我们第一次分别评估了患有UE运动障碍的慢性卒中患者的RetST和RubST微结构。我们证明，具有最大UE协同严重程度和中风后手部损伤的个体在CL RetST中具有最高的FA，这种模式与髓鞘形成增加一致，并提示神经可塑性重组。由于RetST通路的微观结构，特别是，是敏感的异常关节耦合和手相关的运动障碍在慢性中风，它可以帮助测试特定的，新颖的，反协同神经康复干预的影响，从轻偏瘫恢复。
Following hemiparetic stroke, precise, individuated control of single joints is often replaced by highly stereotyped patterns of multi-joint movement, or abnormal limb synergies, which can negatively impact functional use of the paretic arm. One hypothesis for the expression of these synergies is an increased dependence on bulbospinal pathways such as the rubrospinal (RubST) tract and especially the reticulospinal (RetST) tracts, which co-activate multiple muscles of the shoulder, elbow, wrist, and fingers. Despite indirect evidence supporting this hypothesis in humans poststroke, it still remains unclear whether it is correct. Therefore, we used high-resolution diffusion tensor imaging (DTI) to quantify white matter microstructure in relation to severity of arm synergy and hand-related motor impairments. DTI was performed on 19 moderately to severely impaired chronic stroke individuals and 15 healthy, age-matched controls. In stroke individuals, compared to controls, there was significantly decreased fractional anisotropy (FA) and significantly increased axial and radial diffusivity in bilateral corona radiata and body of the corpus callosum. Furthermore, poststroke, the contralesional (CL) RetST FA correlated significantly with both upper extremity (UE) synergy severity (r = −0.606, p = 0.003) and hand impairment (r = −0.609, p = 0.003). FA in the ipsilesional RubST significantly correlated with hand impairment severity (r = −0.590, p = 0.004). For the first time, we separately evaluate RetST and RubST microstructure in chronic stroke individuals with UE motor impairment. We demonstrate that individuals with the greatest UE synergy severity and hand impairments poststroke have the highest FA in the CL RetST a pattern consistent with increased myelination and suggestive of neuroplastic reorganization. Since the RetST pathway microstructure, in particular, is sensitive to abnormal joint coupling and hand-related motor impairment in chronic stroke, it could help test the effects of specific, and novel, anti-synergy neurorehabilitation interventions for recovery from hemiparesis.