Lim Vanessa K, Bradshaw John L, Nicholls Michael E R, Altenmüller Eckart
Department of Psychology, Unviersity of Auckland, New Zealand.
Ann N Y Acad Sci. 2005 Dec;1060:349-59. doi: 10.1196/annals.1360.029.
Auditory evoked potentials (AEPs) were examined in patients with musician's cramp (focal dystonia) in order to determine whether these patients have electrophysiological changes in a sensory system that is not usually associated with symptoms. All participants were professional guitarists and were required to listen to 2,000 monaurally presented stimuli (middle C, with duration of 7 ms). During one block, 250 stimuli were presented to one ear. Once a block was finished, another block was presented in the other ear; in total there were eight blocks of stimuli. During this task, EEGs from 10 scalp electrodes and one bipolar eye channel were continuously recorded. There were no significant latency or topographical differences in the electrophysiological recordings. However, there was a significant group difference in the peak-to-peak amplitude of the P1-N1a component. The patients had a larger peak-to-peak difference than controls (1.63 vs. 0.62 microV). The P1 and N1a are cortically generated potentials. Patients with focal dystonia had an increase in activity compared to controls when processing simple auditory stimuli. Such changes in electrophysiological responses may be a result of increases in excitation or lack of inhibition; alternatively the changes may represent cross-modal maladaptive plasticity from the somatosensory modality to the auditory modality. Thus, this study provides further evidence that patients with focal dystonia have alterations of the central nervous system that are not limited to their symptomatic sensory domain.
对患有音乐家痉挛（局灶性肌张力障碍）的患者进行听觉诱发电位（AEP）检查，以确定这些患者在一个通常与症状无关的感觉系统中是否存在电生理变化。所有参与者均为专业吉他手，他们被要求单耳聆听2000次呈现的刺激（中央C音，持续时间7毫秒）。在一个时段中，向一只耳朵呈现250次刺激。一个时段结束后，在另一只耳朵呈现另一个时段；总共进行八个时段的刺激。在这项任务期间，持续记录来自10个头皮电极和一个双眼双极通道的脑电图。电生理记录中没有明显的潜伏期或地形图差异。然而，P1-N1a成分的峰峰值幅度存在显著的组间差异。患者的峰峰值差异大于对照组（1.63微伏对0.62微伏）。P1和N1a是皮质产生的电位。与对照组相比，局灶性肌张力障碍患者在处理简单听觉刺激时活动增加。电生理反应的这种变化可能是兴奋增加或抑制不足的结果；或者这些变化可能代表从体感模式到听觉模式的跨模态适应不良可塑性。因此，本研究提供了进一步的证据，表明局灶性肌张力障碍患者存在中枢神经系统改变，且不限于其有症状的感觉领域。
