Abstract: Objective    To explore the diagnosis and the efficacy of canalith  respositioning procedure(CRP) in patients with paroxysmal positional vertigo (BPPV) of anterior semicircular canal (ASC). Methods    In this research, a retrospective study of 41 patients with ASC-BPPV was performed, then the positioning tests and the CRP were analyzed. Results    In 28 individuals (68.3%) presented typical positional nystagmus during the positioning test for PSC-BPPV under the BPPV diagnosis and therapy system, 19 individuals had torsional nystagmus component and 9 individuals only had pure positional down beat nystagmus. In 35 individuals (84.6%) presented typical positional nystagmus during the positioning test for SSC-BPPV, 30 individuals had torsional nystagmus component and 5 individuals only had pure positional down beat nystagmus. In 38 patients had unilateral lesion, 30 were judged by torsional nystagmus component, 3 with pure positional down beat nystagmus but without torsional component were judged by the unilateral nystagmus and 5 with bilateral pure positional down beat nystagmus but without torsional component were judged by the obvious different strength of the vertigo and nystagmus, and 3 patients were difficult to judge the affected side.  In 38 patients had unilateral lesion, 23 were with the left AC involvement and 15 were with the right AC involvement. By once treatment, 28 patients were cured, 12 were improved and 1 was invalid. Conclusion    BPPV diagnosis and therapy system should be recommended for its exact curative effect in the process off diagnosis and treatment of BPPV.

Key words: Benign paroxysmal positional vertigo, Superior semicircular canal, Therapeutics, Positioning test