Clinical Characteristics of Unsustainable Vertigo In Patients With Vestibular Neuritis

Background: Vestibular neuritis (VN) is the most common peripheral cause of acute vestibular syndrome. The typical features of VN are characterized by consistent vertigo or gait instability, persisting from one day to several weeks. Canal paresis of ≥25% in caloric testing is traditionally considered the hallmark of VN. However, owing to the wide application of video head impulse tests (vHITs), which precisely locate affected semicircular canals, unsustainable vertigo and instability in patients with VN have attracted interest. In this article, we retrospectively analyzed the clinical features in patients with VN and episodic vertigo, aiming to expand the atypical clinical features and effective indicator of VN.Methods: This retrospective study enrolled 57 patients with VN. Among them, patients with symptomatic (vertigo or gait instability) remission of more than 3 times per day for more than 1 hour each time were selected for unsustainable vertigo (UV) group, while subjects without significant relief period were selected for sustainable vertigo (SV) group. Demographic information, clinical manifestations and supplementary examinations of them were collected and analyzed. These patients were followed up with one year to gather prognostic information.Results: Statistical analysis revealed that the incident rate of spontaneous nystagmus (SN) and proportion of severe vertigo (Dizziness Handicap Inventory questionnaire score ≥ 60) in SV group were significantly higher than those in UV group. Pearson correlation revealed that with a longer disease course, the latency of overt saccade was shorter (p < 0.01, R2 = 0.116) and the velocity of overt saccade was slower (p < 0.01, R2 = 0.150) in all patients with VN. All the patients felt relief from their symptoms after two weeks of treatment. During the first year of follow-up, no vertigo or instability reoccurred.Conclusion: This research showed that a lower incident rate of SN and proportion of severe vertigo could explain the episodic syndrome of VN. The latency and velocity of overt saccade can be promising indicators of VN prognosis. Although the pathogenesis of paroxysmal vertigo in VN remains unknown, timely treatment will reduce the risk of vestibular sequelae and emotional disturbance.