Canal conversion after repositioning procedures: comparison of Semont and Epley maneuver.

Although the efficacy of Semont (SM) and Epley maneuvers (EM) for treatment of posterior canal benign paroxysmal positional vertigo (BPPV) is well established, data comparing SM and EM regarding maneuver-induced canal switch are lacking. We prospectively investigated 102 posterior canal BPPV patients after application of the Semont or the Epley maneuver and looked for the appearance of ipsilateral horizontal canal BPPV symptoms. Although treatment success was similar for SM and EM (67 and 76 %, respectively), there was a significant difference in posterior-to-horizontal canal switch rates. In particular, 4 of 51 patients (7.8 %) of the EM group converted to the geotropic type of horizontal canal BPPV, whereas none of the 51 SM patients exhibited a canal switch. All four patients were cleared with a single barbecue maneuver. Our data suggest a small but significant difference in canal switch rate between EM and SM, which could be partly explained by the higher number of maneuver steps during which the head is in the dependent position throughout the EM.