[Clinical analysis of benign paroxysmal positional vertigowith multiple canal involvement]

Objective:To compare the clinical features and outcomes between patients with multi-canal benign paroxysmal positional vertigo(BPPV) and single-canal BPPV.Method:Five-hundred and seventy-eight patients with BPPV were retrospectively analyzed and divided into three groups: single-canal BPPV(526 cases),multi-canal BPPV in unilateral ear(11 cases) and multi-canal BPPV in both ears(41 cases).All patients were diagnosed by using the Dix-Hallpike test or roll test and treated with the canalith repositioning procedure.The following factors,including aetiology,age,sex,response to treatment and recurrence,were compared among the three groups.Results:①Greater percentage of idiopathic cases were identified in single-canal(66.2%:48.2%,P<0.01).Traumatic origin and prior history of BPPV were more common in bilateral multi-canal(41.6%:9.2%,P<0.05)and unilateral multi-canal (36.2%:0,P<0.01)respectively.②The recurrence rate was higher in multi-canal BPPV(40.4%:14.3%,P<0.01).Conclusion:Idiopathic BPPV is more common in single-canal BPPV.Potential causes may be identified in multi-canal BPPV.However,over 90% of the patients with single-canal and multi-canal BPPV are cured.