The outcome of the canalith repositioning procedure for benign paroxysmal positional vertigo: are there any characteristic features of treatment failure cases?

To demonstrate the success rate of the canalith repositioning procedure (CRP) in our clinic and to establish any characteristic features of cases of treatment failure, we reviewed clinical records of 62 patients who were diagnosed with posterior semicircular canal-benign paroxysmal positional vertigo (BPPV) and treated with the CRP. The basic strategy of the CRP was to rotate the involved canal slowly in the plane of gravity so that free-floating materials could migrate into the utricle only once. After the procedure we instructed patients to keep their heads upright for 10 h and not to sleep on the affected ear for 2 weeks. After the initial treatment, successful results were obtained in 51 of the 62 patients (82.2%). After the second treatment, 56 patients (90.3%) experienced success. Six patients (9.7%) did not obtain resolution even after the second treatment. While 46 patients were diagnosed with idiopathic BPPV, in 16 patients a different diagnosis was determined (head injury in 7 patients, Ménière's disease in 2, vestibular neuritis in 2 and unilateral sensorineural hearing loss in 5). We categorized these 16 patients as having secondary BPPV. Patients with idiopathic BPPV showed a significantly higher success rate with CRP than those with secondary BPPV. Patients with secondary BPPV may have quantitatively or qualitatively different lesions than those with idiopathic BPPV.