Neural and Muscular Determinants of Dorsiflexor Weakness in Chronic Stroke Survivors
Neural and Muscular Determinants of Dorsiflexor Weakness in Chronic Stroke Survivors
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DOI：
10.1123/mcj.17.3.283
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发表时间：
2013-07-01
期刊：
影响因子：
1.1
通讯作者：
Rice, Charles L.
中科院分区：
文献类型：
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作者：
Klein, Cliff S.;Power, Geoffrey A.;Rice, Charles L.
很少有人研究神经和肌肉缺陷对同一中风受试者虚弱的贡献。我们使用磁共振成像（MRI）测定了7名慢性卒中受试者（40-67岁）双侧背屈肌的最大自主收缩（MVC）和50 Hz扭矩、激活（抽搐内插）、肌电图（EMG）振幅和拮抗剂共激活以及肌肉体积。在7名无卒中的对照受试者（24-69岁）中也记录了MVC和50 Hz扭矩。对侧肢体的MVC扭矩小于同侧肢体（29.8 +/- 21.3 Nm vs. 42.5 +/- 12.0 Nm，p = 0.04），并且与激活缺陷（r（2）= 0.77）和EMG振幅缺陷（r（2）= 0.71）相关。拮抗剂共激活百分比在肢体之间没有显著差异。肌肉体积、50 Hz扭矩和比扭矩（50 Hz扭矩/肌肉体积）在两侧之间也没有差异。中风后萎缩是常见的概念并没有得到结果的支持。我们的研究结果表明，移动的中风幸存者的背屈肌无力不能用萎缩或扭矩产生能力降低来解释，这表明核心因素发挥了重要作用。
Few examined the contribution of neural and muscular deficits to weakness in the same stroke subject. We determined maximal voluntary contraction (MVC) and 50 Hz torques, activation (twitch interpolation), electromyographic (EMG) amplitude and antagonist coactivation, and muscle volume using magnetic resonance imaging (MRI) of the dorsiflexors bilaterally in 7 chronic stroke subjects (40-67 y). Recordings of MVC and 50 Hz torque were also done in 7 control subjects (24-69 y) without stroke. The MVC torque was smaller in the contralesional than ipsilesilesional limb (29.8 +/- 21.3 Nm vs. 42.5 +/- 12.0 Nm, p = .04), and was associated with deficits in activation (r(2) = .77) and EMG amplitude (r(2) = .71). Antagonist coactivation percentage was not significantly different between limbs. Muscle volume, 50 Hz torque, and specific torque (50Hz torque/muscle volume) were also not different between sides. The concept that atrophy is commonplace after stroke is not supported by the results. Our findings indicate that dorsiflexor weakness in mobile stroke survivors is not explained by atrophy or reduced torque generating capacity suggesting an important role for central factors.