Ackermann H, Hertrich I, Daum I, Scharf G, Spieker S
Department of Neurology, University of Tübingen, Germany.
Mov Disord. 1997 Nov;12(6):1019-27. doi: 10.1002/mds.870120628.
The various components of the central motor system are expected to play a similar role in speech production and in upper limb control. Slowed articulatory performance, therefore, must be expected in disorders of the corticobulbar tracts, cerebellum, and basal ganglia. Using an optoelectronic device, the present study recorded lower lip trajectories during production of sentence utterances in patients with Parkinson's disease (PD), Huntington's disease (HD), cerebellar atrophy (CA), and pseudobulbar palsy (PB). The various subject groups showed a similar range of overall motor disability. Patients with CA and PB exhibited slowed movement execution in terms of a reduced ratio of peak velocity to maximum amplitude ("stiffness"). In contrast to upper limb motor control, the lip excursions showed an uncompromised shape of velocity profiles. Two different patterns emerged in HD. A single patient suffering from the akinetic-rigid Westphal variant of this disease had articulatory hypometria, whereas the remaining subjects showed significant bradykinesia under increased temporal demands, concomitant with normal movement amplitudes. The PD patients had unimpaired velocity-displacement relationships. Presumably, biomechanical constraints such as the rather small excursions of articulatory lower lip gestures or the scarce spindle supply of facial muscles account for the observed discrepancies between upper limb and speech motor control in PD.
中枢运动系统的各个组成部分预计在言语产生和上肢控制中发挥类似作用。因此，在皮质延髓束、小脑和基底神经节疾病中，必然会出现发音表现迟缓的情况。本研究使用光电设备记录了帕金森病（PD）、亨廷顿病（HD）、小脑萎缩（CA）和假性延髓麻痹（PB）患者在说出句子时的下唇轨迹。各个受试者组的整体运动功能障碍程度相似。CA和PB患者在运动执行方面表现出迟缓，表现为峰值速度与最大幅度之比（“僵硬程度”）降低。与上肢运动控制不同，唇部运动的速度曲线形状未受影响。HD患者出现了两种不同模式。一名患有这种疾病的运动不能-强直型韦斯特法尔变种的患者出现了发音运动减少，而其余受试者在时间要求增加时表现出明显的运动迟缓，同时运动幅度正常。PD患者的速度-位移关系未受损害。据推测，诸如发音时下唇动作幅度较小或面部肌肉的肌梭供应稀少等生物力学限制因素，解释了PD患者在上肢和言语运动控制方面观察到的差异。
