Effect of dynamic balance during the onset of benign paroxysmal positional vertigo on residual dizziness after successful repositioning: a multicenter prospective cohort study / 中华耳鼻咽喉头颈外科杂志

ABSTRACT

Objective: To explore the characteristics of dynamic balance during the onset of benign paroxysmal positional vertigo (BPPV) and its prediction of residual symptoms after successful repositioning. Methods: From January 2018 to August 2019, patients diagnosed with unilateral posterior semicircular canal or horizontal semicircular canal BPPV were consecutively enrolled from five otolaryngology clinics in Shanghai. The dynamic balance function was measured by sensory organization test (SOT) before repositioning maneuver, and the residual symptoms and its duration were followed up from one week to up to three months. Results: A total of 260 patients were recruited. After excluding 17 cases, 243 cases were successfully followed up including 89 males and 154 females, with an average age of (52.9±13.0) years. There were 175 cases of posterior semicircular BPPV, 61 cases of horizontal semicircular BPPV and 7 cases of canal conversion (from horizontal to posterior semicircular). Among 243 patients, 118 cases reported residual symptoms, with an incidence of 48.6%. The results of SOT showed that 58.0%(141/243) of the patients had abnormal vestibular input and 41.6%(101/243) were categorized as "near falls". With respect to the detailed residual symptoms, 47 cases (39.8%) reported unsteadiness or floating, 35 cases (29.7%) had fogginess/heaviness feeling, 22 cases (18.6%) had transient dizzy while head moving, and 15 cases (12.7%) reported that the symptom was too subtle to describe. Compared with the group without residual symptoms, the group with residual symptoms had more abnormal vestibular input(χ²=67.25, P<0.001) and near falls(χ²=74.78, P<0.001) as identified by SOT test. Cox proportional hazards regression failed to reveal any SOT results having significantly impact on the duration of residual symptoms [abnormal vestibular input (HR= 0.93, 95%CI 0.48, 1.80), and near falls (HR= 0.90, 95%CI 0.56, 1.46)]. Kaplan-Meier survival analysis showed that there was no significant difference in the duration of residual symptoms among patients with different SOT manifestations [Log rank (Mantel-Cox) test, P>0.05]. Conclusions: The impaired dynamic balance during the onset of BPPV is characterized by "abnormal vestibular input". The residual symptoms are mainly characterized by unsteadiness or floating feeling. The defect of dynamic balance function is a predictor of the residual symptoms after successful repositioning, but not for the duration of such symptoms.