Neurologische Klinik, Klinikum rechts der Isar, Technische Universität München, Ismaninger Strasse 22, D-81675 München, Germany.
Neurology. 2010 Jun 1;74(22):1790-7. doi: 10.1212/WNL.0b013e3181e0f784.
Embouchure dystonia is a focal task-specific dystonia affecting the complex interplay of lower facial, jaw, and tongue muscles in musicians playing brass or woodwind instruments. Although it is highly disabling for affected patients, little is known about the pathophysiologic basis of this rare movement disorder.
We therefore studied sensorimotor activation patterns during 2 orofacial motor tasks in brass players with embouchure dystonia by using fMRI. A "dystonia-specific" task involved buzzing at an instrument-specific, fully functional mouthpiece. A "neutral" task involved simply blowing into a tube.
Compared with healthy brass players, patients with embouchure dystonia showed significantly increased activation of somatotopic face representations within the bilateral primary sensorimotor cortex and of the bilateral premotor cortex during buzzing at the mouthpiece. Interestingly, a similar activation pattern was present during the neutral task when patients were clinically asymptomatic.
Sensorimotor overactivity could reflect deficient subcortical and intracortical inhibition as well as abnormal sensorimotor integration and reorganization in musicians with embouchure dystonia. Because this overactivity was also found during the neutral task, it could be a crucial pathophysiologic factor predisposing for the development of orofacial dystonia rather than a mere correlate of dystonic motor output.
口周肌张力障碍是一种局灶性运动障碍，影响吹奏铜管乐器或木管乐器的音乐家的面部、下颌和舌部肌肉的复杂相互作用。尽管它对受影响的患者有高度的致残性，但对这种罕见运动障碍的病理生理基础知之甚少。
因此，我们通过 fMRI 研究了患有口周肌张力障碍的铜管演奏者在进行 2 种口面部运动任务时的感觉运动激活模式。一个“特定于肌张力障碍”的任务涉及到用乐器专用的、功能齐全的吹嘴吹奏。一个“中性”任务则只是简单地吹气到管内。
与健康的铜管演奏者相比，患有口周肌张力障碍的患者在吹奏吹嘴时，双侧初级感觉运动皮层和双侧运动前皮层内的躯体感觉面部代表区的激活明显增加。有趣的是，当患者处于临床无症状状态时，在进行中性任务时也存在类似的激活模式。
感觉运动过度可能反映了皮质下和皮质内抑制不足，以及患有口周肌张力障碍的音乐家的感觉运动整合和重组异常。由于这种过度活跃也在中性任务中发现，因此它可能是导致口面部肌张力障碍发展的关键病理生理因素，而不仅仅是运动输出的相关性。
