Tabrizi Yousef Moghadas, Mazhari Shahrzad, Nazari Mohammad Ali, Zangiabadi Nasser, Sheibani Vahid, Azarang Sahar
Neuroscience Research Center, Kerman University of Medical Sciences, Kerman, Iran.
Clin Neurol Neurosurg. 2013 Sep;115(9):1738-44. doi: 10.1016/j.clineuro.2013.04.002. Epub 2013 Apr 29.
Motor imagery (MI) impairment has been reported in individuals with multiple sclerosis (MS). The present study was designed to investigate neural evidence for MI impairment and its relationship to working memory in MS patients.
The study participants included 24 early stage MS patients (age: 22-40/mean=32.7 years; M/F=4/20; years since duration: 1-10/mean=5.8) and 24 age-, gender-, and education-matched controls (age: 21-40/mean=31.8 years; M/F=5/19). Event-related potentials were recorded during a mental hand rotation task, in which participants were instructed to judge the laterality of hands displayed in different orientations. Furthermore, the Paced Auditory Serial Addition Test (PASAT) was used for assessment of working memory.
At the behavioral level, MS patients were significantly less accurate and much slower (accuracy: 83.80 ± 7.72%; reaction time: 1665.95 ± 269.82 ms) than controls (accuracy: 88.35 ± 7.68%; reaction time: 1505.16 ± 225.11 ms). At the neural level, MS patients showed a significantly reduced amplitude (MS: 0.99 ± 0.89 μv, controls: 1.46 ± 1.00 μv) and delayed peak latency (MS: 458.45 ± 67.60 ms, controls: 417.91 ± 62.47 ms) at P3 for mental rotation effect. Moreover, there were significant correlations between individuals' PASAT scores and performance of the hand rotation task.
The results of the present study demonstrate MI impairment in patients with MS at both the behavioral and neural level. Neuronal activity dysfunction (decreased and delayed activity) in patients with MS provides new insights into MI impairment. Furthermore, our findings suggest the contribution of working memory dysfunction to compromised MI ability in patients with MS.
已有报道称多发性硬化症（MS）患者存在运动想象（MI）障碍。本研究旨在探究MS患者MI障碍的神经学证据及其与工作记忆的关系。
研究参与者包括24名早期MS患者（年龄：22 - 40岁/平均 = 32.7岁；男/女 = 4/20；病程：1 - 10年/平均 = 5.8年）和24名年龄、性别及教育程度匹配的对照者（年龄：21 - 40岁/平均 = 31.8岁；男/女 = 5/19）。在一项心理手部旋转任务中记录事件相关电位，该任务要求参与者判断以不同方向展示的手部的偏侧性。此外，使用听觉序列加法测验（PASAT）评估工作记忆。
在行为水平上，MS患者的准确性显著低于对照者，且速度更慢（准确性：83.80 ± 7.72%；反应时间：1665.95 ± 269.82毫秒），而对照者的准确性为88.35 ± 7.68%，反应时间为1505.16 ± 225.11毫秒。在神经水平上，MS患者在心理旋转效应的P3波处振幅显著降低（MS组：0.99 ± 0.89微伏，对照组：1.46 ± 1.00微伏），且峰值潜伏期延迟（MS组：458.45 ± 67.60毫秒，对照组：417.91 ± 62.47毫秒）。此外，个体的PASAT分数与手部旋转任务的表现之间存在显著相关性。
本研究结果表明，MS患者在行为和神经水平上均存在MI障碍。MS患者的神经元活动功能障碍（活动减少和延迟）为MI障碍提供了新的见解。此外，我们的研究结果表明工作记忆功能障碍对MS患者受损的MI能力有影响。
