Supplementary Material for: Head-Shaking Aids in the Diagnosis of Acute Audiovestibular Loss due to Anterior Inferior Cerebellar Artery Infarction

<b><i>Objective:</i></b> To determine the patterns and diagnostic value of head-shaking nystagmus (HSN) in patients with acute audiovestibular loss. <b><i>Method:</i></b> Eighteen patients underwent evaluation of spontaneous nystagmus, gaze-evoked nystagmus, HSN, head impulse test, ocular tilt reaction, subjective visual vertical, bithermal caloric tests, and pure-tone audiogram. The findings were compared with those of 21 patients with labyrinthitis.<b><i> Results:</i></b> Fifteen patients (83%) exhibited HSN, and the horizontal HSN usually beat contralesionally (10/14, 71%). However, 9 (50%) patients also showed patterns of central HSN that included perverted HSN (n = 7), HSN in the opposite direction of spontaneous nystagmus (n = 4), and HSN beating towards unilateral canal paresis or abnormal head impulse testing (n = 3). Overall, central HSN, gaze-evoked nystagmus, and normal head impulse testing were specific for anterior inferior cerebellar artery (AICA) infarction. Moreover, central HSN was the only sign that indicated stroke in 1 of our patients with isolated audiovestibular syndrome. Lesion subtraction analyses revealed that damage to the flocculus was relatively frequent in patients with perverted HSN. <b><i>Conclusions:</i></b> In AICA infarction, HSN was common with both peripheral and central patterns. Careful evaluation of HSN may provide clues for AICA infarction in patients with acute audiovestibular loss.

<b><i>研究目的：</i></b> 探讨急性前庭听觉损失患者的摇头性眼震（head-shaking nystagmus, HSN）的表现模式与诊断价值。<b><i>研究方法：</i></b> 纳入18例患者，对其开展自发性眼震、凝视诱发性眼震、摇头性眼震（HSN）、头脉冲试验、眼倾斜反应、主观视觉垂直、双温冷热试验及纯音听阈测试评估，并将检测结果与21例迷路炎患者的结果进行对比。<b><i>研究结果：</i></b> 15例患者（占比83%）出现摇头性眼震，其中水平型摇头性眼震的快相通常朝向健侧（10/14，71%）。另有9例（50%）患者表现出中枢性摇头性眼震模式，包括反向性摇头性眼震（n=7）、与自发性眼震方向相反的摇头性眼震（n=4），以及朝向单侧半规管麻痹或头脉冲试验异常侧摆动的摇头性眼震（n=3）。总体而言，中枢性摇头性眼震、凝视诱发性眼震及正常头脉冲试验，对小脑前下动脉（anterior inferior cerebellar artery, AICA）梗死具有诊断特异性。此外，在1例孤立性前庭听觉综合征患者中，中枢性摇头性眼震是唯一提示脑卒中的体征。病灶减法分析显示，出现反向性摇头性眼震的患者中，绒球受损的比例相对较高。<b><i>研究结论：</i></b> 在小脑前下动脉梗死患者中，摇头性眼震较为常见，且可兼具周围性与中枢性表现模式。对摇头性眼震进行细致评估，可为急性前庭听觉损失患者的小脑前下动脉梗死诊断提供参考线索。