Determination of the time course of caloric nystagmus in patients with spinocerebellar degeneration using caloric step stimulus procedure

Abstract

Conclusions: The step stimulus procedure can provide information on the time course of the vestibulo-ocular reflex. Spinocerebellar degeneration and aging seem to shorten the time constant of the onset of the vestibulo-ocular reflex, causing a rapid rise up. Failure of the central processing of velocity storage might contribute to this rapid rise up.

Objectives: The aim of this study is to evaluate the time course characteristics of the vestibulo-ocular reflex in patients with spinocerebellar degeneration.

Methods: Ten patients (20 ears) and 22 healthy subjects (30 ears) underwent caloric test using the step stimulus procedure. We evaluated the time course of caloric VOR and calculated the parameters of the time constant of an activation and adaptation response. We compared between the control and SCD groups to elucidate the time course characteristics of caloric VOR in patients with SCD.

Results: Spinocerebellar degeneration seems to shorten the time constant of the activation response by caloric irrigation with 20 °C, 7l/min air. However, aging also possibly contributes to this shortening. No change was observed in the time constant of the adaptation response.

Chinese abstract

结论：步骤刺激手术可以提供关于前庭眼反射时程的信息。脊髓小脑退化和衰老似乎缩短了前庭眼反射发作的时间常数, 导致快速上升。速率存储的中央处理失败可能加速了这种快速上升。

目的：本研究的目的是评估脊髓小脑退化患者前庭眼反射的时程特征。

方法：10例（20个耳）和22例健康受试者（30个耳）接受了用步骤刺激手术进行的热量测试。我们评估了热量VOR的时间过程, 并计算了激活和适应反应的时间常数的参数。我们比较了对照组和SCD组, 以便明确SCD患者的热量VOR的时程特征。

结果：脊髓小脑退化似乎通过用20摄氏度每分钟71升的空气的热量灌注来缩短活化反应的时间常数。然而, 老龄化也可能导致这种缩短。没有观察到适应反应的时间常数的变化。

Keywords:

• Caloric test
• step stimulus
• spinocerebellar degeneration
• vestibulo-ocular reflex
• time constant

Disclosure statement

The authors report no conflict of interest. The authors alone are responsible for the content and writing of the paper.