Bilateral Sequential Vestibular Neuritis: Report of Three Cases

OBJECTIVE: To describe the clinical characteristics, vestibular function test results, and recovery patterns of patients with bilateral sequential vestibular neuritis (BSVN), and to highlight its diagnostic challenges and pathophysiological implications. PATIENTS: Three male patients (aged 39, 47, and 57 y) diagnosed with bilateral sequential vestibular neuritis were retrospectively analyzed, each presenting with a second episode involving the contralateral ear after a symptom-free interval. INTERVENTIONS: All patients underwent comprehensive vestibular assessments during both episodes, including caloric testing, video head impulse test (vHIT), and cervical and ocular vestibular evoked myogenic potentials (VEMP). MAIN OUTCOME MEASURES: Quantitative measures of vestibular dysfunction (canal paresis, vestibulo-ocular reflex gain, VEMP asymmetry ratio), symptom severity, and interval between sequential attacks were analyzed to assess the pattern of recovery and compensation. RESULTS: All patients initially presented with unilateral vestibular neuritis followed by contralateral involvement after 2 to 5 years. The first 2 patients achieved complete or near-complete recovery, while the third developed persistent bilateral vestibulopathy with prolonged oscillopsia and imbalance. Across all cases, spontaneous nystagmus and vertigo during the second attack were milder than those in the first, suggesting central compensation and the influence of residual vestibular function. CONCLUSIONS: BSVN is an exceptionally rare condition demonstrating both peripheral restoration and central adaptive mechanisms. Sequential vestibular testing provides valuable insights into its heterogeneous presentations and recovery patterns. Recognition of this condition is crucial for accurate diagnosis, patient counseling, and long-term management.