Follow-up Examination of Vibration-Induced Nystagmus in Patients with Unilateral Vestibular Neuritis

ABSTRACT

BACKGROUND AND OBJECTIVES: The aim of this study was to verify if vibration-induced nystagmus in patients with vestibular neuritis changed over time and to compare the results of vibration-induced nystagmus (VIN) test to those of caloric test. MATERIALS AND METHOD: We compared VIN results with those of caloric testing in 23 patients (MF = 1112, 15~67 years old) with unilateral vestibular neuritis seen at onset and in follow-up for around 2 months. The eye movement recordings were made and the maximum slow-phase eye velocities (SPV) were calculated during vibration. If spontaneous nystagmus was present, it was subtracted from the slow-phase eye velocities of VIN. RESULTS: In acute stage, VIN of which SPV was directed towards the lesioned side was observed in 21 (91%). In follow-up, VIN of which SPV was directed towards the lesioned side was observed in 19 (83%). There was a significant decrease of the SPV of VIN over time. Significant correlations were observed in between canal paresis & SPV of VIN in both acute and follow-up stages. CONCLUSION: Our findings show that VIN test can predict the severity of vestibular asymmetry not only in acute stage but also in follow-up stage. Our results suggest that vibration-induced nystagmus might represent the peripheral vestibular asymmetry in patients with vestibular neuritis.