To determine the short term therapeutic efficacies of Gufoni maneuver and mastoid oscillation in apogeotropic type of benign paroxysmal positional vertigo (BPPV) involving the horizontal semicircular canal (HC-BPPV), a randomized, prospective, sham-controlled study was conducted.

The apogeotropic type of benign paroxysmal positional vertigo involving the horizontal canal (HC-BPPV) is likely due to otolithic debris in the anterior arm of the canal (canalithiasis) or the debris attached to the cupula (cupulolithiasis). It is important to seek the method to convert treatment-resistant apogeotropic form to the more treatment-responsive geotropic form in HC-BPPV. Recent randomized trials demonstrated that head shaking maneuver was more effective than the modified Semont maneuver and the Gufoni and head shaking maneuvers showed similar efficacy in treating apogeotropic HC-BPPV. Moreover, new repositioning maneuver using mastoid vibration showed good efficacies in patients with apogeotropic HC-BPPV in recent study. So we tried to compare the short term therapeutic efficacies of Gufoni maneuver and mastoid oscillation in apogeotropic HC-BPPV with a randomized, prospective, sham-controlled study.

Inclusion Criteria:

1. history of vertigo associated with changes in head position
2. direction-changing horizontal nystagmus beating toward the uppermost ear (apogeotropic nystagmus) in both turning positions detected with Frenzel glasses or videoculography in the Head turning test
3. vertigo associated with the elicited nystagmus
4. symptom within 2 weeks
5. put one's signature on consent

Exclusion Criteria:

1. patients with identifiable central nervous system disorders that could explain the positional vertigo and nystagmus
2. the patients with apogeotropic form which was transited from geotropic after previous therapeutic maneuvers
3. the patients who transited from apogeotropic from vertical canal BPPV during study
4. patients who had possible cause of secondary BPPV such as Meniere's disease, migraine or recent trauma history
5. patients whose affected ear cannot be identified
6. patients with multiple canal atypical positional nystagmus or who were treated previously with repositioning maneuvers were excluded.
7. patients with cervical or lumbar spine problem

217 patients enrolled in the study but 8 retracted their agreements.