Ikoma K, Samii A, Mercuri B, Wassermann E M, Hallett M
Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
Neurology. 1996 May;46(5):1371-6. doi: 10.1212/wnl.46.5.1371.
To assess the excitability of the motor system, we studied 11 patients with task-specific dystonia and 11 age-matched normal subjects. The dominant side was affected in nine of the patients. We delivered transcranial magnetic stimuli at different stimulus intensities and with different levels of muscle facilitation to the side contralateral to the side of electromyographic recording, and recorded motor evoked potentials (MEPs) from the flexor carpi radialis muscles bilaterally. The threshold intensity for eliciting MEPs at rest did not differ between patients and normal subjects. We compared the affected side in patients with the dominant side in normal subjects. With facilitation, the percentage of the area of the MEP to the M wave (MEP area%) was similar in both groups at low stimulus intensities, but with increasing stimulus intensity the increase in the MEP area% was greater in patients than in normal subjects (ANOVA, p < 0.001). The increase in MEP area% was similar in both groups with increasing facilitation levels. The duration of the silent period was similar in patients and normal subjects. We conclude that cortical motor excitability is increased in dystonia.
为评估运动系统的兴奋性，我们研究了11例任务特异性肌张力障碍患者和11名年龄匹配的正常受试者。9例患者的优势侧受累。我们在不同刺激强度和不同肌肉易化水平下，向肌电图记录侧的对侧施加经颅磁刺激，并双侧记录桡侧腕屈肌的运动诱发电位（MEP）。静息时引出MEP的阈值强度在患者和正常受试者之间无差异。我们将患者的受累侧与正常受试者的优势侧进行比较。在易化状态下，两组在低刺激强度时MEP面积占M波面积的百分比（MEP面积%）相似，但随着刺激强度增加，患者的MEP面积%增加幅度大于正常受试者（方差分析，p<0.001）。随着易化水平增加，两组的MEP面积%增加相似。静息期持续时间在患者和正常受试者中相似。我们得出结论，肌张力障碍患者的皮质运动兴奋性增加。
