背景:临床动态姿势描记术集中在俯仰和横滚上,而不是偏航平面不稳定性测量。与健康对照(HC)受试者相比,这种强调可能并不代表平衡缺陷患者在临床姿势和步态任务中观察到的轴不稳定性。也不是基于与前庭眼反射(VOR)缺陷的相关性的预期不稳定性。为了检查前庭丢失时的轴稳定性变化,我们测量了躯干在所有三个方向上的摇摆(俯仰,roll,和偏航)在急性单侧前庭神经炎(aUVN)患者的姿势和步态任务中,并将结果与HC的结果进行了比较。还检查了VOR的同时变化,并将其与躯干平衡缺陷相关联。
方法:在aUVN发病6天内记录的11名患者(平均年龄61岁)的结果与8名年龄匹配的健康对照(HCs)的结果进行了比较。所有受试者都进行了两足站立任务,眼睛闭上泡沫(s2ecf),半步态任务-行走八个串联步骤(tan8),和四个步态任务-头部横向旋转行走3m,投球,或闭上眼睛(w3hr,w3hp,w3ec),走过四个24厘米高的屏障,间隔1米(巴尔)。任务\'峰-峰偏航,俯仰角和滚转角,和角速度是用安装在L1-3上的陀螺仪系统(SwayStarTM)测量的,特定轴,平衡控制指标(BCI),使用角度(a)进行串联步态和障碍任务,和所有其他任务的角速度(v),如下:轴BCI=(2×2ecf)v+1.5×(w3hr+w3hp+w3ec)v+(tan8+12×barr)a.
结果:偏航和沥青BCI显着增加(p≤0.004)(88%和30%,分别)比aUVN患者的滚动BCI。对于HC,仅偏航BCI而非俯仰BCI(p=0.002)大于侧倾BCI(72%)。BCIaUVN与HC的差异是音高,偏航,并以55、44和31%的速度滚动,分别(p≤0.002)。相对于滚动的这种差异对应于已知的更大的偏航平面,而不是滚动平面的不对称性(40与22%)以下基于VOR的aUVN响应。然而,VOR响应中的较低俯仰平面不对称性(3.5%)与平衡控制测试中观察到的俯仰平面不稳定性不一致。UVL受试者的俯仰平面不稳定性增加,然而,与侧倾和偏航高度相关。
结论:这些结果表明,对于aUVN患者和HC来说,在临床平衡任务期间,大于俯仰和横滚躯干运动的偏航是常见的。然而,aUVN导致较大的增加在俯仰比偏航平面不稳定性和较小的增加在滚动平面不稳定性。相对于滚动的这种差异对应于已知的比滚动平面不对称性更大的偏航平面(40与22%)在aUVN后观察到VOR反应。然而,VOR响应中的较低俯仰平面不对称性(3.5%)与俯仰平面中的增强运动不对应,在平衡控制任务中观察到。前庭诱发的肌源性电位(Vemps)的不对称性是否与俯仰平面平衡控制的缺陷更好地相关,尚待研究。当前的结果为定向特异性平衡反应的临床测试提供了强有力的理由,尤其是偏航和俯仰,以及偏航和滚转的平衡结果与VOR不对称性的联系。
BACKGROUND: Clinical dynamic posturography concentrates on the pitch and roll but not on the yaw plane instability measures. This emphasis may not represent the axis instability observed in clinical stance and gait tasks for patients with balance deficits in comparison to healthy control (HC) subjects, nor the expected instability based on correlations with vestibulo-ocular reflex (VOR) deficits. To examine the axis stability changes with vestibular loss, we measured trunk sway in all three directions (pitch, roll, and yaw) during the stance and gait tasks of patients with acute unilateral vestibular neuritis (aUVN) and compared the results with those of HC. Concurrent changes in VORs were also examined and correlated with trunk balance deficits.
METHODS: The results of 11 patients (mean age of 61 years) recorded within 6 days of aUVN onset were compared within those of 8 age-matched healthy controls (HCs). All subjects performed a two-legged stance task-standing with eyes closed on foam (s2ecf), a semi-gait task-walking eight tandem steps (tan8), and four gait tasks-walking 3 m with head rotating laterally, pitching, or eyes closed (w3hr, w3hp, w3ec), and walking over four barriers 24 cm high, spaced 1 m apart (barr). The tasks\' peak-to-peak yaw, pitch and roll angles, and angular velocities were measured with a gyroscope system (SwayStarTM) mounted at L1-3 and combined into three, axis-specific, balance control indexes (BCI), using angles (a) for the tandem gait and barriers task, and angular velocities (v) for all other tasks, as follows: axis BCI = (2 × 2ecf)v + 1.5 × (w3hr + w3hp + w3ec)v + (tan8 + 12 × barr)a.
RESULTS: Yaw and pitch BCIs were significantly (p ≤ 0.004) greater (88 and 30%, respectively) than roll BCIs for aUVN patients. For HCs, only yaw but not pitch BCIs were greater (p = 0.002) than those of roll (72%). The order of BCI aUVN vs. HC differences was pitch, yaw, and roll at 55, 44, and 31%, respectively (p ≤ 0.002). This difference with respect to roll corresponded to the known greater yaw plane than roll plane asymmetry (40 vs. 22%) following aUVN based on VOR responses. However, the lower pitch plane asymmetry (3.5%) in VOR responses did not correspond with the pitch plane instability observed in the balance control tests. The increases in pitch plane instability in UVL subjects were, however, highly correlated with those of roll and yaw.
CONCLUSIONS: These results indicate that greater yaw than pitch and roll trunk motion during clinical balance tasks is common for aUVN patients and HCs. However, aUVN leads to a larger increase in pitch than yaw plane instability and a smaller increase in roll plane instability. This difference with respect to roll corresponds to the known greater yaw plane than roll plane asymmetry (40 vs. 22%) following aUVN observed in VOR responses. However, the lower pitch plane asymmetry (3.5%) in VOR responses does not correspond with the enhanced movements in the pitch plane, observed in balance control tasks. Whether asymmetries in vestibular-evoked myogenic potentials (Vemps) are better correlated with the deficits in pitch plane balance control remains to be investigated. The current results provide a strong rationale for the clinical testing of directional specific balance responses, especially yaw and pitch, and the linking of balance results for yaw and roll to VOR asymmetries.