脑卒中患者大腿肌肉协调性评价的MRI对比研究

Thigh muscle function in stroke patients revealed by velocity-encoded cine phase-contrast MRI

目的探讨脑卒中对下肢肌肉协调性的影响以及康复训练对肌肉功能的改善作用。方法共选取10例脑卒中偏瘫患者(处于基线期)和6例年龄和性别与之相匹配的正常对照者。采用速度编码相位对比MRI(VE-PC MRI)和表面肌电图(sEMG)评价膝关节屈伸运动中股四头肌和大腿后部及内侧肌群(腘绳肌和内收肌群)的肌肉协调性以及康复训练对上述肌肉的影响。结果VE-PC MRI检查结果显示,在基线期间,患侧股直肌的最大运动速度较正常对照者显著降低(P<0.01),且股直肌和股肌(股内侧肌、股中间肌、股外侧肌)达到最大运动速度的时间具有非同步性,而正常对照者具有同步性。患肢伸膝时大腿内、后组肌群和股四头肌的共同收缩较正常对照者明显(P<0.05),共同收缩主要归因于内收肌群的活动。sEMG结果表明,患侧股直肌和股二头肌在膝屈伸运动时的活动水平显著高于正常对照者(P<0.05),各组间股内侧肌的活动水平差异无统计学意义。患侧股二头肌和股四头肌的共同收缩水平较正常对照者显著(P<0.05)。经平均40d康复训练后随访发现,脑卒中患者Barthel指数评分显著提高(P<0.05),患侧股四头肌各部分肌肉活动趋向于同步性。结论脑卒中患者股直肌和股肌的收缩具有非同步性,股直肌在脑卒中后其功能受拟较严重。VE-PC MRI可定量评价在体肌肉功能活动信息,对于指导行之有效的个体化康复治疗具有重要意义。

Objective To examine how stroke affects muscle coordination and whether muscle function will be improved after rehabilitation. Methods Ten stroke patients with mild hemiparesis and six age-and sex-matched controls were investigated at baseline. Velocity-encoded phase-contrast magnetic resonance imaging （VE-PC MRI） and surface electromyography （sEMG） were performed to evaluate muscle coordination of thigh muscles during knee extension and flexion and the effect of rehabilitation. Results Using VE-PC MRI, we found that the peak velocity of rectus femoris was lower in the affected limb （P 〈0.01 ）. The affected rectus femoris and vasti reached peak velocity asynchronously. The co-contraction of the combined hamstring and adductor, and quadriceps femoris was significantly higher in the affected limb than in Control （ P 〈 0.05 ）. Results from sEMG showed that the rectus femoris and biceps femoris had a consistently high activity pattern in the affected limb. No difference was found between the groups in the vastus medialis activity. After 6-week therapy, the Barthel index improved significantly. The movement of different portions of affected quadriceps femoris changed towards synchronisation. Conclusion Timing of peak velocity between RF and vasti was asynchronous in the hemiparetic limb. Biarticular RF muscle is the more impaired muscle post stroke. VE-PC MRI can provide quantitative in vivo measurements of muscles function, which can be utilised to render the therapy more efficient and individually tailored.