Millar Jennifer L, Gimmon Yoav, Roberts Dale, Schubert Michael C
Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, MD, United States.
Laboratory of Vestibular NeuroAdaptation, Department of Otolaryngology - Head and Neck Surgery, Baltimore, MD, United States.
Front Neurol. 2020 Feb 20;11:79. doi: 10.3389/fneur.2020.00079. eCollection 2020.
Gaze stability exercises are a critical component of vestibular rehabilitation for individuals with vestibular hypofunction and many studies reveal the rehabilitation improves functional performance. However, few studies have examined the vestibular physiologic mechanisms (semicircular canal; otolith) responsible for such recovery after patients with vestibular hypofunction complete gaze and gait stability exercises. The purpose of this study was to compare behavioral outcome measures (i.e., visual acuity during head rotation) with physiological measures (i.e., gain of the vestibulo-ocular reflex) of gaze stability following a progressive vestibular rehabilitation program in patients following unilateral vestibular deafferentation surgery (UVD). We recruited = 43 patients ( = 18 female, mean 52 ± 13 years, range 23-80 years) after unilateral deafferentation from vestibular schwannoma; = 38 (25 female, mean 46.9 ± 15.9 years, range 22-77 years) age-matched healthy controls for dynamic visual acuity testing, and another = 28 (14 female, age 45 ± 17, range 20-77 years) healthy controls for video head impulse testing. Data presented is from = 19 patients (14 female, mean 48.9 ± 14.7 years) with UVD who completed a baseline assessment ~6 weeks after surgery, 5 weeks of vestibular physical therapy and a final measurement. As a group, subjective and fall risk measures improved with a meaningful clinical relevance. Dynamic visual acuity (DVA) during active head rotation improved [mean ipsilesional 38.57% ± 26.32 ( = 15/19)]; mean contralesional 39.96% ± 22.62 ( = 12/19), though not uniformly. However, as a group passive yaw VOR gain (mean ipsilesional pre 0.44 ± 0.18 vs. post 0.44 ± 0.15; mean contralesional pre 0.81 ± 0.19 vs. post 0.85 ± 0.09) did not show any change ( ≥ 0.4) after rehabilitation. The velocity of the overt compensatory saccades during ipsilesional head impulses were reduced after rehabilitation; no other metric of oculomotor function changed ( ≥ 0.4). Preserved utricular function was correlated with improved yaw DVA and preserved saccular function was correlated with improved pitch DVA. Our results suggest that 5 weeks of vestibular rehabilitation using gaze and gait stability exercises improves both subjective and behavioral performance despite absent change in VOR gain in a majority of patients, and that residual otolith function appears correlated with such change.
注视稳定性训练是前庭功能减退患者前庭康复的关键组成部分，许多研究表明这种康复能改善功能表现。然而，很少有研究探讨在前庭功能减退患者完成注视和步态稳定性训练后，负责这种恢复的前庭生理机制（半规管；耳石）。本研究的目的是比较单侧前庭神经切断术（UVD）患者在进行渐进性前庭康复计划后，注视稳定性的行为结果指标（即头部旋转时的视力）与生理指标（即前庭眼反射增益）。我们招募了43例单侧前庭神经鞘瘤去传入术后患者（18例女性，平均年龄52±13岁，范围23 - 80岁）；38例（25例女性，平均年龄46.9±15.9岁，范围22 - 77岁）年龄匹配的健康对照者进行动态视力测试，另有28例（14例女性，年龄45±17岁，范围20 - 77岁）健康对照者进行视频头脉冲测试。呈现的数据来自19例UVD患者（14例女性，平均年龄48.9±14.7岁），他们在术后约6周完成了基线评估，接受了5周的前庭物理治疗并进行了最终测量。总体而言，主观和跌倒风险指标有了具有临床意义的改善。主动头部旋转时的动态视力（DVA）有所提高[患侧平均提高38.57%±26.32（15/19）]；对侧平均提高39.96%±22.62（12/19），但并非一致。然而，总体而言，被动偏航VOR增益（患侧术前平均0.44±0.18与术后0.44±0.15；对侧术前平均0.81±0.19与术后0.85±0.09）在康复后没有显示出任何变化（P≥0.4）。康复后患侧头部脉冲时明显的代偿性扫视速度降低；眼动功能的其他指标没有变化（P≥0.4）。椭圆囊功能保留与偏航DVA改善相关，球囊功能保留与俯仰DVA改善相关。我们的结果表明，尽管大多数患者的VOR增益没有变化，但使用注视和步态稳定性训练进行5周的前庭康复可改善主观和行为表现，并且残余耳石功能似乎与这种变化相关。
