Square wave manoeuvre for apogeotropic variant of horizontal canal benign paroxysmal positional vertigo in neck restricted patients

OBJECTIVE: We aimed to describe the clinical features of the apogeotropic variant of horizontal canal benign paroxysmal positional vertigo (HC BPPV-AG) in a cluster of patients with restrictive neck movement disorders and a new therapeutic manoeuvre for its management. METHODS: In a retrospective review of cases from an ambulatory tertiary referral center, patients with HC BPPV-AG in combination with neck movement restriction that prevented any classical manual repositioning procedure or who were refractory to canalith repositioning manoeuvres, were treated with a new manoeuvre comprised of sequential square-wave pattern of head and body supine rotations while nystagmus was being monitored, until either an apogeotropic to geotropic conversion or resolution of the nystagmus was observed. RESULTS: Fifteen patients were studied. All but one [14/15 cases] showed a positive therapeutic response to the repositioning procedure in a single session. In two cases, a direct relief of vertigo and elimination of nystagmus was observed without an intermediate geotropic phase. Although in three patients the affected ear was not initially identified, it was ultimately identified and successfully treated by the square wave manoeuvre in all of them. CONCLUSIONS: The square-wave manoeuvre is an alternative for HC BPPV-AG treatment in either cases with neck restriction, where the affected side is not well identified at the bedside or when other manoeuvres fail to resolve the HC BPPV-AG.