Department of Neurological and Visual Sciences, University of Verona, Clinic Hospital Gianbattista Rossi, Verona, Italy.
Magn Reson Imaging. 2010 Jun;28(5):646-52. doi: 10.1016/j.mri.2009.12.023. Epub 2010 Feb 1.
Whereas several studies have used functional magnetic resonance imaging (fMRI) to investigate motor recovery, whether therapy to decrease post-stroke hypertonus alters central motor patterns remains unclear. In this study, we used continuous electromyography (EMG)-fMRI to investigate possible changes in movement-related brain activation in patients receiving Botulinum toxin (BoNT-A) for hand-muscle hypertonus after chronic stroke.
We studied eight stroke patients all of whom had hemiparesis and associated upper-limb hypertonus. All patients underwent an fMRI-EMG recording and clinical-neurological assessment before BoNT-A and 5 weeks thereafter. The handgrip motor task during imaging was fixed across both patients and controls. The movements were metronome paced, movement amplitude and force were controlled with a plastic orthosis, dynamometer and EMG recording. An age-matched control group was recruited from among healthy volunteers underwent the same fMRI-EMG recording.
Before BoNT-A, while patients moved the paretic hand, fMRI detected wide bilateral activation in the sensorymotor areas (SM1), in the supplementary motor area (SMA) and cerebellum. After BoNT-A blood oxygenation level-dependent (BOLD) activation decreased in ipsilateral and contralateral motor areas and became more lateralized. BOLD activation decreased also in ipsilateral cerebellar regions and in the SMA.
Changes in peripheral upper-limb hypertonus after BoNT-A were associated to an improvement in active movements and more lateralized and focalized activation of motor areas. The clinical and EMG-fMRI coregistration technique we used to study hand-muscle hypertonus in patients receiving BoNT-A after chronic stroke should be useful in future studies seeking improved strategies for post-stroke neurorehabilitation.
虽然已有几项研究使用功能磁共振成像（fMRI）来研究运动功能的恢复，但针对降低卒中后肌肉痉挛的治疗方法是否会改变中枢运动模式，目前仍不清楚。在这项研究中，我们使用连续肌电图（EMG）-fMRI 来研究接受肉毒毒素（BoNT-A）治疗慢性卒中后手肌肉痉挛的患者，其运动相关脑激活是否可能发生变化。
我们研究了 8 名卒中患者，他们均存在偏瘫和上肢相关的肌肉痉挛。所有患者在接受 BoNT-A 治疗前和治疗后 5 周均接受了 fMRI-EMG 记录和临床神经评估。成像过程中的手握运动任务在患者和对照组中是固定的。运动由节拍器控制，运动幅度和力由塑料矫形器、测力计和肌电图记录来控制。我们从健康志愿者中招募了一个年龄匹配的对照组，他们接受了相同的 fMRI-EMG 记录。
在接受 BoNT-A 治疗前，当患者移动患手时，fMRI 在感觉运动区（SM1）、辅助运动区（SMA）和小脑检测到广泛的双侧激活。在接受 BoNT-A 治疗后，患侧和对侧运动区的血氧水平依赖（BOLD）激活降低，并变得更加偏侧化。同侧小脑区域和 SMA 的 BOLD 激活也降低。
BoNT-A 治疗后，外周性上肢肌肉痉挛的变化与主动运动的改善以及运动区更偏侧化和更聚焦的激活有关。我们用于研究接受慢性卒中后 BoNT-A 治疗的患者手部肌肉痉挛的临床和 EMG-fMRI 配准技术，应该对未来寻求改善卒中后神经康复策略的研究有用。
