Supplemental Digital Content is Available in the Text. Background and Purpose: Convergence of the eyes during head rotation increases the gain (eye velocity/head velocity) of the vestibulo-ocular reflex (VOR). We sought to know whether convergence would increase the VOR gain (mean + SD) in unilateral vestibular hypofunction (UVH). Methods: Vestibulo-ocular reflex gain during ipsi- and contralesional horizontal head rotation at near (15 cm) and far (150 cm) targets was measured in 22 subjects with UVH and 12 healthy controls. Retinal slip was estimated (retinal slip index [RSI]) as the difference between ideal VOR gain (no retinal slip) and the actual VOR gain. Results: Convergence did not significantly enhance VOR gain for ipsilesional rotation (mean difference, 0.04; 95% confidence interval [CI], −0.01 to 0.09), near viewing (0.77 ± 0.34) versus far viewing (0.72 ± 0.29), yet the VOR gain during contralesional rotation was greater for near viewing (1.20 ± 0.23) than for far viewing (0.97 ± 0.21; mean difference, 0.23; 95% CI, 0.13-0.32). In the 36% of subjects with recovery of their ipsilesional VOR gain, the vergence effect trended to recover (far VOR gain: 1.06 ± 0.17 vs near VOR gain 1.16 ± 0.21; mean difference, 0.10; 95% CI, −0.02 to 0.22). Ipsilesional head rotation induced greater retinal slip for near (RSI = 0.90 ± 0.34) targets than for far targets (RSI = 0.35 ± 0.29; mean difference, 0.56; 95% CI, 0.51-0.61). Discussion and Conclusions: The convergence-mediated VOR gain enhancement is preserved during contralesional but impaired during ipsilesional head rotation. Recovery of ipsilesional passive VOR gain does not equate to restored convergence enhancement, although it did increase ∼10%. These data suggest head motion viewing near targets will increase retinal slip, which warrants consideration as a gaze stability exercise for subjects with UVH. Video Abstract available for more insights from the authors (see Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A325).

中文翻译：

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单侧前庭功能减退的会聚前庭眼反射

补充数字内容在文本中可用。背景和目的：头部旋转过程中眼睛的会聚增加了前庭眼反射 (VOR) 的增益（眼睛速度/头部速度）。我们试图知道收敛是否会增加单侧前庭功能减退 (UVH) 的 VOR 增益（平均值 + SD）。方法：在 22 名 UVH 受试者和 12 名健康对照者中测量了在近 (15 cm) 和远 (150 cm) 目标的同侧和对侧水平头部旋转期间的前庭眼反射增益。视网膜滑动被估计为理想 VOR 增益（无视网膜滑动）和实际 VOR 增益之间的差异（视网膜滑动指数 [RSI]）。结果：收敛没有显着提高同侧旋转的 VOR 增益（平均差异，0.04；95% 置信区间 [CI]，-0.01 至 0.09），近视（0.77 ± 0. 34) 与远视 (0.72 ± 0.29) 相比，近视 (1.20 ± 0.23) 的对侧旋转过程中的 VOR 增益大于远视 (0.97 ± 0.21；平均差异，0.23；95% CI，0.13-0.32) . 在 36% 的同侧 VOR 增益恢复的受试者中，聚散效应趋于恢复（远 VOR 增益：1.06 ± 0.17 与近 VOR 增益 1.16 ± 0.21；平均差异，0.10；95% CI，-0.02 至 0.22） . 与远距离目标（RSI = 0.35 ± 0.29；平均差异，0.56；95% CI，0.51-0.61）相比，同侧头部旋转对近（RSI = 0.90 ± 0.34）目标引起更大的视网膜滑动。讨论和结论：会聚介导的 VOR 增益增强在对侧期间保留，但在同侧头部旋转期间受损。同侧被动 VOR 增益的恢复并不等同于恢复的收敛增强，尽管它确实增加了约 10%。这些数据表明在目标附近观察头部运动会增加视网膜滑动，这值得考虑作为 UVH 受试者的凝视稳定性练习。视频摘要可提供作者的更多见解（参见视频，补充数字内容 1，可在：http://links.lww.com/JNPT/A325 获得）。