The Bascule/Pendular Maneuver: A Novel Repositioning Strategy for the Apogeotropic Variant of Posterior Canal BPPV

BACKGROUND: Benign paroxysmal positional vertigo (BPPV) is the most common peripheral vestibular disorder and most frequently involves the posterior semicircular canal (PSC). Atypical apogeotropic variants of PSC-BPPV may present with pure down-beating positional nystagmus, mimicking contralateral anterior semicircular canal involvement and resulting in diagnostic and therapeutic uncertainty. OBJECTIVE: To assess the effectiveness of the Bascule/Pendular maneuver in managing patients with pure down-beating positional nystagmus and suspected apogeotropic PSC-BPPV. METHODS: A total of 178 patients presenting with pure down-beating positional nystagmus without a torsional component were evaluated using a standardized diagnostic protocol under video-Frenzel goggle monitoring. All patients underwent the Bascule/Pendular maneuver, a modification of the classical Semont maneuver designed to mobilize otoconial debris along the vertical canal planes (Left Anterior-Right Posterior and Right Anterior-Left Posterior), regardless of precise lateralization. Conversion of nystagmus from the apogeotropic to the geotropic variant was considered the primary outcome. RESULTS: The maneuver was well tolerated, with no procedural interruptions or complications. Immediate conversion to the geotropic variant was achieved in 86 patients (48.3%) after a single maneuver. In the remaining patients, successful conversion was obtained after additional maneuvers, most commonly following a second application on the contralateral plane. Once geotropization was achieved, all patients were successfully treated using a standard posterior canal repositioning maneuver. CONCLUSIONS: The Bascule/Pendular maneuver is a practical and effective approach for patients presenting with pure down-beating positional nystagmus and suspected apogeotropic PSC-BPPV. By facilitating conversion to the geotropic form, it allows prompt treatment with conventional repositioning maneuvers and may represent a useful first-line strategy in atypical BPPV presentations.