Department of Neurology, Christian-Albrecht-University, Kiel, Germany.
Mov Disord. 2012 Sep 1;27(10):1268-75. doi: 10.1002/mds.25061. Epub 2012 Jun 12.
Postural disturbances in advanced Parkinson's disease are less responsive to therapy than other cardinal motor signs. The vestibulocollic reflex represents one brain-stem neuronal circuit involved in postural adjustments. The objective of this study was to investigate the vestibulocollic reflex in parkinsonian patients and the effects of subthalamic stimulation and dopa by recording vestibular-evoked myogenic potentials. After overnight withdrawal of medication, 20 patients with Parkinson's disease with (6 men, 4 women; mean age, 64.4 ± 2.2 years) or without (8 men, 2 women; mean age, 62.7 ± 3.9 years) implanted subthalamic electrodes in different treatment conditions were compared with 10 age-matched controls (5 men, 5 women; mean age, 59.6 ± 2.4 years). Vestibular-evoked myogenic potentials were recorded by electromyographic surface electrodes applied to both sternocleidomastoid muscles (band-pass filter, 8-1600 Hz; sampling rate, 5 kHz) and averaged in response to bilateral auditory tone bursts (120 dB SPL; sine waves, 7 ms; 1000 Hz) applied through earphones. Adjusted vestibular-evoked myogenic potential amplitudes were significantly smaller in parkinsonian patients than in controls, in particular in patients without surgery. Administration of dopa, but not subthalamic stimulation, significantly increased amplitudes. Onset latencies were similar for all groups and treatment conditions. Decreased vestibular-evoked myogenic potential amplitudes in parkinsonian patients suggest reduced vestibular nuclei excitability within the brain stem, which is modulated by dopa but not by subthalamic stimulation. This suggests different pathways for the action of both treatment modalities in Parkinson's disease and may explain clinical differences in terms of postural disturbances. © 2012 Movement Disorder Society.
姿势障碍在晚期帕金森病中的反应不如其他主要运动迹象敏感。前庭眼反射代表参与姿势调整的一个脑干神经元回路。本研究的目的是通过记录前庭诱发的肌电图来研究帕金森病患者的前庭眼反射以及丘脑底核刺激和多巴胺的作用。在停药过夜后，将 20 名接受不同治疗条件的植入丘脑底核电极的帕金森病患者（6 名男性，4 名女性；平均年龄 64.4 ± 2.2 岁）或未接受治疗的帕金森病患者（8 名男性，2 名女性；平均年龄 62.7 ± 3.9 岁）与 10 名年龄匹配的对照组（5 名男性，5 名女性；平均年龄 59.6 ± 2.4 岁）进行比较。通过应用于双侧胸锁乳突肌的肌电图表面电极（带通滤波器，8-1600 Hz；采样率，5 kHz）记录前庭诱发的肌电图，并通过耳机施加双侧听觉音调爆发（120 dB SPL；正弦波，7 ms；1000 Hz）进行平均。调整后的前庭诱发的肌电图幅度在帕金森病患者中明显小于对照组，特别是在未接受手术的患者中。给予多巴胺但不是丘脑底核刺激会显著增加幅度。潜伏期在所有组和治疗条件下相似。帕金森病患者的前庭诱发肌电图幅度降低表明脑干中的前庭核兴奋性降低，这种降低可被多巴胺调节，但不受丘脑底核刺激调节。这表明两种治疗方式在帕金森病中的作用途径不同，并且可能解释了姿势障碍方面的临床差异。
