Rottach K G, Wohlgemuth W A, Dzaja A E, Eggert T, Straube A
Dept. of Neurology, Klinikum Augsburg.
J Neurol. 2002 Sep;249(9):1200-5. doi: 10.1007/s00415-002-0806-1.
Oculomotor symptoms such as downbeat nystagmus can be due to side effects of drugs. We investigated the clinical effects as well as the eye movement symptoms after intravenous administration of opiates (pethidine and fentanyl). Eye movements were recorded with the magnetic search coil technique. All four normal subjects showed a transient disturbance of eye fixation with downbeat nystagmus, a range of saccadic intrusions and oscillations, including square wave jerks and saccadic pulses, lasting from 10 to 15 minutes. The gain of sinusoidal VOR and smooth pursuit was moderately decreased; in particular the vertical pursuit showed an upward velocity offset. On the basis of the clinical findings and of recent diprenorphine PET findings in humans, which detected opiod binding sites in the cerebellum and the known inhibitory action of opiates, we hypothesized that a cerebellar dysfunction occurs after opiate administration which could possibly be mediated by inhibition of the parallel fiber activation of the Purkinje cells. Furthermore, opiate binding sites in the vestibular nuclei could be responsible for the vertical vestibular tonus imbalance involved in the pathophysiolgy of downbeat nystagmus.
动眼神经症状，如下跳性眼球震颤，可能是药物副作用所致。我们研究了静脉注射阿片类药物（哌替啶和芬太尼）后的临床效果以及眼动症状。采用磁搜索线圈技术记录眼动。所有四名正常受试者均出现短暂的眼注视障碍，并伴有下跳性眼球震颤、一系列眼球扫视侵入和振荡，包括方波急跳和眼球扫视脉冲，持续10至15分钟。正弦VOR和平稳跟踪的增益适度降低；特别是垂直跟踪显示出向上的速度偏移。基于临床发现以及近期人类二丙诺啡PET研究结果（该研究在小脑中检测到阿片类结合位点以及阿片类药物已知的抑制作用），我们推测阿片类药物给药后会发生小脑功能障碍，这可能是由浦肯野细胞平行纤维激活受抑制介导的。此外，前庭核中的阿片类结合位点可能是导致下跳性眼球震颤病理生理学中垂直前庭张力失衡的原因。
