Department of Biomedical Engineering, McGill University, Montreal, QC, Canada.
Department of Biomedical Engineering, Johns Hopkins University, Baltimore, USA.
Sci Rep. 2021 Jan 12;11(1):517. doi: 10.1038/s41598-020-79756-3.
The vestibular system is vital for maintaining balance and stabilizing gaze and vestibular damage causes impaired postural and gaze control. Here we examined the effects of vestibular loss and subsequent compensation on head motion kinematics during voluntary behavior. Head movements were measured in vestibular schwannoma patients before, and then 6 weeks and 6 months after surgical tumor removal, requiring sectioning of the involved vestibular nerve (vestibular neurectomy). Head movements were recorded in six dimensions using a small head-mounted sensor while patients performed the Functional Gait Assessment (FGA). Kinematic measures differed between patients (at all three time points) and normal subjects on several challenging FGA tasks, indicating that vestibular damage (caused by the tumor or neurectomy) alters head movements in a manner that is not normalized by central compensation. Kinematics measured at different time points relative to vestibular neurectomy differed substantially between pre-operative and 6-week post-operative states but changed little between 6-week and > 6-month post-operative states, demonstrating that compensation affecting head kinematics is relatively rapid. Our results indicate that quantifying head kinematics during self-generated gait tasks provides valuable information about vestibular damage and compensation, suggesting that early changes in patient head motion strategy may be maladaptive for long-term vestibular compensation.
前庭系统对于维持平衡和稳定注视至关重要，前庭损伤会导致姿势和注视控制受损。在这里，我们研究了前庭丧失及其随后代偿对自愿行为期间头部运动运动学的影响。在进行涉及前庭神经（前庭神经切断术）的手术肿瘤切除之前、之后 6 周和 6 个月，我们测量了前庭神经鞘瘤患者的头部运动。使用小型头戴式传感器在六个维度上记录头部运动，同时患者进行功能性步态评估（FGA）。在几个具有挑战性的 FGA 任务中，运动学测量值在所有三个时间点都与患者和正常受试者之间存在差异，这表明前庭损伤（由肿瘤或神经切断术引起）以未被中枢代偿正常化的方式改变头部运动。与前庭神经切断术相关的不同时间点的运动学测量值在术前和术后 6 周状态之间有很大差异，但在术后 6 周和 >6 个月状态之间变化不大，这表明影响头部运动学的代偿相对较快。我们的结果表明，在自发步态任务期间量化头部运动学可提供有关前庭损伤和代偿的有价值信息，表明患者头部运动策略的早期变化可能不利于长期前庭代偿。
