Buma Floor E, van Kordelaar Joost, Raemaekers Matthijs, van Wegen Erwin E H, Ramsey Nick F, Kwakkel Gert
Center of Excellence for Rehabilitation, Rehabilitation Centre De Hoogstraat, Rembrandtkade 10, 3583TM, Utrecht, The Netherlands.
Department of Neurology and Neurosurgery, Rudolf Magnus Institute of Neuroscience, UMC Utrecht, PO Box 85060, 3508AB, Utrecht, The Netherlands.
Exp Brain Res. 2016 Jul;234(7):2077-2089. doi: 10.1007/s00221-015-4538-8. Epub 2016 Mar 15.
It is unclear whether additionally recruited sensorimotor areas in the ipsilesional and contralesional hemisphere and the cerebellum can compensate for lost neuronal functions after stroke. The objective of this study was to investigate how increased recruitment of secondary sensorimotor areas is associated with quality of motor control after stroke. In seventeen patients (three females, fourteen males; age: 59.9 ± 12.6 years), cortical activation levels were determined with functional magnetic resonance imaging (fMRI) in 12 regions of interest during a finger flexion-extension task in weeks 6 and 29 after stroke. At the same time points and by using 3D kinematics, the quality of motor control was assessed by smoothness of the grasp aperture during a reach-to-grasp task, quantified by normalized jerk. Ipsilesional premotor cortex, insula and cerebellum, as well as the contralesional supplementary motor area, insula and cerebellum, correlated significantly and positively with the normalized jerk of grasp aperture at week 6 after stroke. A positive trend towards this correlation was observed in week 29. This study suggests that recruitment of secondary motor areas at 6 weeks after stroke is highly associated with increased jerk during reaching and grasping. As jerk represents the change in acceleration, the recruitment of additional sensorimotor areas seems to reflect a type of control in which deviations from an optimal movement pattern are continuously corrected. This relationship suggests that additional recruitment of sensorimotor areas after stroke may not correspond to restitution of motor function, but more likely to adaptive motor learning strategies to compensate for motor impairments.
目前尚不清楚中风后同侧和对侧半球以及小脑中额外募集的感觉运动区域是否能够代偿丧失的神经元功能。本研究的目的是调查中风后二级感觉运动区域募集增加与运动控制质量之间的关系。在17例患者（3名女性，14名男性；年龄：59.9±12.6岁）中，在中风后第6周和第29周进行手指屈伸任务期间，使用功能磁共振成像（fMRI）测定12个感兴趣区域的皮质激活水平。在相同时间点，通过3D运动学，在伸手抓握任务期间，根据抓握孔径的平滑度评估运动控制质量，以标准化加加速度进行量化。中风后第6周，同侧运动前皮质、岛叶和小脑，以及对侧辅助运动区、岛叶和小脑与抓握孔径的标准化加加速度显著正相关。在第29周观察到这种相关性呈阳性趋势。本研究表明，中风后6周二级运动区域的募集与伸手和抓握过程中加加速度增加高度相关。由于加加速度代表加速度的变化，额外感觉运动区域的募集似乎反映了一种控制类型，即不断纠正与最佳运动模式的偏差。这种关系表明，中风后感觉运动区域的额外募集可能并不对应于运动功能的恢复，而更可能是为了补偿运动障碍的适应性运动学习策略。
