Acute vestibular asymmetry disorder: a new disease entity in acute vestibular syndrome?

Abstract

Background: Acute vestibular syndrome (AVS) is characterized by the rapid onset of vertigo, nausea, vomiting and gait unsteadiness, which lasts for days.

Aims/objectives: We report cases as acute vestibular asymmetry disorder (AVAD), with presentations that mimic vestibular neuritis (VN) but without central lesions.

Materials and methods: We retrospectively reviewed records of patients presenting with acute spontaneous vertigo lasting more than 24 h from January 2011 to June 2016. Among 341 patients, five showed different findings that did not indicate either VN or stroke. We analyzed the clinical features and vestibular assessments of these patients.

Results: All five patients showed spontaneous nystagmus continuing for several days. However, head impulse tests (HITs) did not reveal a corrective saccade. Brain magnetic resonance imaging showed no abnormal lesions. The bithermal caloric test revealed directional preponderance without canal paresis. Finally, the slow harmonic test of the rotatory chair revealed unilateral high gain and phase within the normal range, but a significantly asymmetric response was observed. No patients showed recurrence during follow-up.

Conclusions and significance: Our study suggests that a normal HIT in AVS is not always a dangerous sign indicating an acute stroke. From our observations, we propose that AVAD would be a new disease entity within AVS.

Chinese abstract

背景：急性前庭综合征（AVS）以快速发作的眩晕、恶心、呕吐和步态不稳为特征, 并可持续数天。

目的：我们报告的病例为急性前庭不对称性疾病（AVAD）, 表现类似前庭神经炎（VN）, 但无中枢病变。

材料与方法：回顾性分析2011年1月至2016年6月急性自发性眩晕患者24小时以上的记录。在341名患者中, 5名患者记录有新的表现, 而这些表现均未显示是VN或中风。我们分析了这些患者的临床特征和前庭评估。

结果：5例患者均显示自发性眼球震颤持续数天。然而, 头部脉冲测试（HITS）没有显示纠正球囊。脑磁共振成像未见异常病变。热双温试验显示定向优势, 无管轻瘫。最后, 旋转椅慢谐波测试显示, 在正常范围内的单边高增益和相位, 但观察到明显的不对称响应。随访期间无患者复发。

结论和意义：我们的研究表明, AVS的正常头部脉冲测试并不总是急性中风的危险信号。根据我们的观察, 我们提出AVAD将是AVS的一种新的疾病。

Keywords:

• Acute vestibular syndrome
• magnetic resonance imaging
• vertigo

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was supported by the Soonchunhyang University Research Fund.