From the Department of Neurology (S.-H.K., S.-U.L., B.-H.C., K.-H.C., S.Y., B.-J.K.), Korea University Medical Center, Seoul; BK21 FOUR Program in Learning Health Systems (B.-J.K.), Korea University, Seoul; Dizziness Center (J.-S.K.), Clinical Neuroscience Center, Seoul National University Bundang Hospital, Seongnam; and Department of Neurology (J.-S.K.), Seoul National University College of Medicine, South Korea.
Neurology. 2023 Jun 6;100(23):e2374-e2385. doi: 10.1212/WNL.0000000000207299. Epub 2023 Apr 19.
The interpretation of video head-impulse tests (video-HITs) can often be complicated, limiting their clinical utility in acute vestibular syndrome. We aimed to determine video-HIT findings in patients with posterior circulation strokes (PCSs) and vestibular neuritis (VN).
We retrospectively analyzed the results of video-HITs in 59 patients with PCS. Irrespective of the actual lesion revealed later on MRIs, ipsilateral and contralateral sides were assigned according to the direction of slow phase of spontaneous nystagmus (SN). Then, the patterns of video-HIT findings were classified according to the vestibulo-ocular reflex (VOR) gain for the horizontal canals; (1) ipsilaterally positive, (2) contralaterally positive, (3) bilaterally normal, and (4) bilaterally positive. The abnormal responses were further defined into (5) wrong-way saccades, (6) perverted, and (7) early acceleration followed by premature deceleration. We also analyzed the asymmetry of the corrective saccadic amplitude between the sides, calculated from the sum of cumulative saccadic amplitudes on both sides. The results were compared with video-HIT results from 71 patients with VN.
Video-HITs were normal in 32 (54%), ipsilaterally positive in 11 (19%), bilaterally positive in 10 (17%), and contralaterally positive in 6 (10%) patients with PCS. Wrong-way saccades were more frequently observed in VN than in PCS (31/71 [44%] vs 5/59 [8%], < 0.001). Saccadic amplitude asymmetry was greater in VN than in PCS (median 100% [interquartile range 82-144, 95% CI 109-160] vs 0% [-29 to 34, -10 to 22, < 0.001]). When differentiating VN from PCS, the sensitivity was 81.7%, and specificity was 91.5% at the cutoff value of 71% for saccadic amplitude asymmetry with an area under the curve (AUC) of 0.91 (95% CI 0.86-0.97). The AUC for saccadic amplitude asymmetry was larger than that for the ipsilateral VOR gain ( = 0.041) and other parameters.
Patients with PCS may show various head-impulse responses that deviate from the findings expected in VN, which include normal, contralaterally positive, and negative saccadic amplitude asymmetry (i.e., greater cumulative saccadic amplitude contralaterally). A thorough analysis of corrective saccades in video-HITs can improve the differentiation of PCS from VN even before MRIs.
视频眼动试验（video-HIT）的解读往往较为复杂，限制了其在急性前庭综合征中的临床应用。本研究旨在探讨后循环卒中（PCSs）和前庭神经炎（VN）患者的 video-HIT 结果。
我们回顾性分析了 59 例 PCS 患者的 video-HIT 结果。根据自发眼震（SN）慢相的方向，将同侧和对侧分为阳性和阴性，无论实际病变后来在 MRI 上的显示如何。然后，根据水平半规管的前庭眼反射（VOR）增益，将 video-HIT 结果分类：（1）同侧阳性，（2）对侧阳性，（3）双侧正常，（4）双侧阳性。异常反应进一步分为（5）反向扫视，（6）倒错，和（7）早期加速后过早减速。我们还分析了从两侧累积扫视幅度之和计算的两侧校正扫视幅度的不对称性。将结果与 71 例 VN 患者的 video-HIT 结果进行比较。
32 例（54%）PCSs 患者的 video-HIT 正常，11 例（19%）同侧阳性，10 例（17%）双侧阳性，6 例（10%）对侧阳性。VN 患者中反向扫视比 PCS 患者更常见（31/71 [44%] vs 5/59 [8%]，<0.001）。VN 患者的扫视幅度不对称性大于 PCS 患者（中位数 100% [四分位距 82-144，95%CI 109-160] vs 0% [-29 至 34，-10 至 22]，<0.001）。在区分 VN 和 PCS 时，以扫视幅度不对称性的截断值 71%为界，敏感性为 81.7%，特异性为 91.5%，曲线下面积（AUC）为 0.91（95%CI 0.86-0.97）。扫视幅度不对称性的 AUC 大于同侧 VOR 增益（=0.041）和其他参数。
PCSs 患者可能表现出各种不同于 VN 预期的眼动反应，包括正常、对侧阳性和负性扫视幅度不对称（即对侧累积扫视幅度更大）。对 video-HIT 中的校正扫视进行彻底分析，甚至在 MRI 之前，就可以提高对 PCS 与 VN 的区分能力。
