Abstract

Objectives
Aim of this study is to investigate the clinical efficacy of the vestibular function tests (VFTs) and the predictability of lesion side of vestibular asymmetry parameters in acute unilateral peripheral vestibulopathy.
Methods
Medical records and results of VFTs (Caloric, rotatory chair and head impulse tests) of 57 patients with acute unilateral vestibulopathy were reviewed retrospectively. The VFTs were examined within 7 days after the clinical onset.
Results
For the caloric test, 74% showed significant canal paresis and the predictability of lesion side was 88%. For the sinusoidal harmonic acceleration test, 91% had low gain in at least one Hz, phase lead showed 70%, 89% showed phase asymmetry and the predictability of lesion side was 90%. For velocity step test, 67% had abnormal Tc asymmetry and the predictability of lesion side was 95%. In bedside head impulse test (HIT), abnormal catch up saccades were observed in 89% and the predictability of lesion side was 100%. For the video HIT, cover or overt catch-up saccades were observed in 95% and the predictability of lesion side was 100%. 100% had low gain on the video HIT, but the lesion sides were uncertain because of bilateral involvements or artifacts.
Conclusion
The most important things in the diagnosis of acute unilateral vestibulopathy are typical clinical symptoms and spontaneous nystagmus. A combination of rotatory, caloric, and head impulse tests will result in a more complete examination of the vestibular system. Among them, head impulse test is recommended as the best tool in acute unilateral vestibulopathy.

• Keywords: acute unilateral vestibulopathy; vestibular neuronitis; vestibular function tests; caloric test; rotatory chair test; head impulse test