Torsional optokinetic nystagmus after unilateral vestibular loss: asymmetry and compensation
Torsional optokinetic nystagmus after unilateral vestibular loss: asymmetry and compensation
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DOI：
10.1093/brain/awh504
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发表时间：
2005-07-01
期刊：
影响因子：
14.5
通讯作者：
Lacour, M
中科院分区：
文献类型：
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作者：
Lopez, C;Borel, L;Lacour, M
对17例梅尼埃病患者行根治性单侧前庭神经切断术(UVN)前、后(1周、1个月、3个月)的扭转视动性眼震(TOKN)进行分析。在不同的恒定角速度下，沿着视线向患侧或健侧进行视动刺激，研究tOKN。用视频眼震图分析tOKN和静止性眼球旋转的动态特性。将患者的表现与10名健康受试者进行比较。结果表明，在UVN后的急性期，患者的tOKN速度严重受损，且与刺激的方向有关：单侧刺激时tOKN速度增加，对侧刺激时tOKN速度降低。这些变化是导致tOKN显著不对称的原因，扭转性慢相眼速在自身方向上占优势。这些变化与静止性眼球向手术侧旋转有关。尽管随着时间的推移，tOKN的缺陷逐渐得到补偿，但tOKN的速度仍然与术前记录的不同，而且tOKN的不对称性在UVN后3个月仍然没有得到补偿。损伤后3个月仍有静止性眼球旋转。这些结果首次描述了单侧前庭缺失后tOKN的缺失和恢复。它们表明，前庭线索有助于视线周围视动刺激时的凝视稳定。他们还强烈地表明，tOKN损害可能是单侧前庭功能丧失后报告的长期不对称功能的一部分。
The aim of this study was to analyse torsional optokinetic nystagmus (tOKN) in 17 patients with Meniere's disease before and after (1 week, 1 month and 3 months) a curative unilateral vestibular neurotomy (UVN). The tOKN was investigated during optokinetic stimulations around the line of sight directed towards either the lesioned or the healthy side, at various constant angular velocities. Dynamic properties of tOKN and static ocular cyclotorsion were analysed using videonystagmography. Patients' performances were compared with those of 10 healthy subjects. The results indicate that, in the acute stage after UVN, patients exhibited drastic impairment of tOKN velocity that depended on the direction of stimulation: tOKN velocity increased for ipsilesional stimulations and decreased for contralesional stimulations. These changes were responsible for a dramatic tOKN asymmetry, with ipsilesional directional preponderance of torsional slow-phase eye velocity. The changes were associated with static ocular cyclotorsion towards the operated side. Despite progressive compensation of tOKN deficits over time, tOKN velocity still differed from that recorded preoperatively, and tOKN asymmetry remained uncompensated 3 months after UVN. A static ocular cyclotorsion remained up to 3 months after lesion. These results are the first description of tOKN deficits and recovery after unilateral vestibular loss. They show that vestibular cues contribute to gaze stabilization during optokinetic stimulation around the line of sight. They also strongly suggest that tOKN impairment could be part of the long-term asymmetrical functions reported after unilateral loss of vestibular functions.