视频头脉冲试验中左右前庭眼反射增益的差异

文献信息

中文摘要

目的： 本研究旨在评估视频头脉冲试验（vHIT）中前庭眼反射（VOR）增益的左右对称性及其相对于冷热试验结果的诊断意义。方法：回顾性分析因头晕就诊并接受双温冷热试验和vHIT的患者。在确定的764例患者中，排除9例双侧前庭功能减退者，最终纳入755例患者进行分析（451例冷热反应对称；304例单侧前庭功能减退（UVH））。在冷热反应正常的受试者中比较两个方向的水平VOR增益，并在UVH患者中根据受累侧进行比较。根据冷热功能减退严重程度进行亚组分析。根据水平VOR增益模式分析冷热试验结果，并评估孤立性单侧低VOR增益（<0.8）对同侧UVH的诊断效能。结果：在冷热结果正常的受试者中，向右VOR增益显著高于向左（1.03 [0.95-1.11] 对 0.93 [0.87-0.99]；p < 0.001）。在UVH患者中，在相当程度的冷热功能减退水平下，右侧UVH的同侧VOR增益显著大于左侧UVH。亚组分析显示，这种差异在轻至中度冷热功能减退患者中显著。孤立性右侧低VOR增益在90.5%的病例中与右侧UVH相关，而孤立性左侧低VOR增益在54.5%的病例中与左侧UVH相关；阳性预测值（PPV）在两侧之间差异显著（90.5% 对 54.5%；p = 0.004）。结论：vHIT中的水平VOR增益显示出与侧别依赖性诊断效能相关的左右不对称性。当对两侧应用相同的VOR增益截断值时，孤立性右侧低VOR增益对同侧UVH的PPV显著高于孤立性左侧低VOR增益。这些发现表明，在解读VOR增益时应考虑头脉冲的方向。

英文摘要

Objectives: The objective of this study was to evaluate left-right symmetry of vestibulo-ocular reflex (VOR) gain on the video head impulse test (vHIT) and its diagnostic implications relative to caloric test results. Methods: Patients presenting with dizziness who underwent a bithermal caloric test and vHIT were retrospectively analyzed. Of 764 patients identified, nine with bilateral vestibular hypofunction were excluded, leaving 755 patients for analysis (451 showing symmetric caloric responses; 304 with unilateral vestibular hypofunction (UVH)). Horizontal VOR gain was compared between directions in subjects with normal caloric responses and according to the affected side in patients with UVH. Subgroup analyses were performed according to caloric weakness severity. Caloric findings were analyzed according to horizontal VOR gain patterns, and the diagnostic performance of isolated unilateral low VOR gain (<0.8) for ipsilateral UVH was evaluated. Results: In subjects with normal caloric results, rightward VOR gain was significantly higher than leftward (1.03 [0.95-1.11] vs. 0.93 [0.87-0.99]; p < 0.001). In patients with UVH, ipsilateral VOR gain was significantly greater in right-sided than in left-sided UVH at comparable levels of caloric weakness. Subgroup analysis showed that this difference was significant in patients with mild-to-moderate caloric weakness. Isolated right low VOR gain was associated with right UVH in 90.5% of cases, whereas isolated left low VOR gain was associated with left UVH in 54.5%; the positive predictive value (PPV) differed significantly between sides (90.5% vs. 54.5%; p = 0.004). Conclusions: Horizontal VOR gain on vHIT showed a left-right asymmetry associated with side-dependent diagnostic performance. When the same VOR gain cutoff was applied to both sides, isolated right low VOR gain had a substantially higher PPV for ipsilateral UVH than isolated left low VOR gain. These findings indicate that the direction of head impulse should be considered when interpreting VOR gain.