The treatment of horizontal canal positional vertigo: our experience in 66 cases.

Objectives/hypothesis: The horizontal semicircular canal variant of paroxysmal positional vertigo (HSC-PPV) shows three subtype nystagmic patterns: 1) bilateral geotropic nystagmus, 2) bilateral apogeotropic nystagmus that may switch into bilateral geotropic, and 3) bilateral apogeotropic nystagmus that never switches into bilateral geotropic. In recent years, many methods of physical treatment have been proposed for HSC-PPV, yet no standard protocol has been defined. We studied the effects of different methods according to each different form of HSC-PPV after a precise definition of the nystagmic and clinical features.

Study Design: A prospective trial of 66 patients with horizontal canal paroxysmal positional vertigo treated with a combination of rotational maneuver and forced prolonged position.

Methods: We evaluated 66 patients with HSC-PPV in its three subtypes. For patients with bilateral geotropic nystagmus, the "barbecue" method was combined with "forced prolonged position." Patients with bilateral geotropic nystagmus were submitted to maneuvers aimed at a switch to bilateral geotropic. The cases that did not switch were submitted to a modified fourth step of the Semont maneuver.

Results: Eighty percent of the patients with bilateral geotropic nystagmus became symptom free within the second session, and in 90% of the patients, symptoms were resolved by the third session. In the bilateral apogeotropic cases, the modified fourth step of the Semont maneuver resulted in 75% of the patients being symptom free.

Conclusions: The correct identification of both nystagmic pattern and site of the lesion is crucial for the choice of physical treatment of HSC-PPV and its success. We have standardized the treatment protocol consisting of a "barbecue" maneuver followed by "forced prolonged position" in cases of geotropic nystagmus and a modified fourth step of the Semont maneuver for apogeotropic nystagmus. Our results appear encouraging because 90% of the entire study group was symptom free after three sessions.